摘要:

Editorial A new journal for the new millennium J. Environ. Monit. 1999 1 1N This first issue of the Journal of Environmental Monitoring (JEM) published by The Royal Society of Chemistry is the culmination of more than two years of market research and discussions with leading experts from industry academia and agencies (national and international) involved with environmental monitoring regulations pertaining to exposures and analytical science. As a result of these deliberations it was considered to be timely to launch a high quality journal dedicated to primary and applied research in environmental and biological monitoring despite our awareness of tightening library and academic budgets. Environmental monitoring is a research area that has seen rapid growth in the last few years but until now the subject matter has been scattered throughout many diVerent journals due to its interdisciplinary nature.JEM hopes to accommodate all relevant components information and developments in a single resource of modest cost. Addressing the needs of an expanding specialist subject JEM is dedicated to all aspects of the measurement of chemical physical and biological agents in outdoor indoor and workplace environments with a view to assessing exposure in relation to adverse environmental and health eVects. Through its focus on exposure assessment (including biological monitoring) JEM targets the interface of analytical science with disciplines concerned with the presence of organic and inorganic contaminants and other agents in the natural and human environments. JEM aims to bring together the many elements involved in monitoring including multi-media environmental sampling and analyses (e.g.of gases aerosols particles chemicals radiation physical agents noise and electric and magnetic fields; their detection and quantitation in air soils sediments tissues or body fluids as well as in emissions eZuents or wastes of natural or anthropogenic origin); measurement of biomarkers of exposure eVect (outcome) or susceptibility; speciation of environmental contaminants; design of sampling strategies; development of associated analytical technologies; advances in monitoring equipment; quality control and assurance; legislative issues regarding exposure limits and acceptable concentrations of contaminants. In addition to original publications JEM will promote this important multidisciplinary area through critical reviews perspectives and appropriate news items.Launching the journal at this time is considered particularly appropriate since the monitoring of the natural and human environments is necessarily linked to other major environmental initiatives. Examples are our eVorts to assess understand and predict changes in the environment such as those associated with the long-range transport of contaminants and global warming or to manage the oceans lakes rivers land air and other natural resources. Establishment of integrated networks for real-time measurements such as those of air pollutants implicated in causing respiratory distress in healthy and susceptible populations is also closely allied to suitable advances in monitoring technology and data management.Further the promulgation and enforcement of cogent regulations for environmental occupational and public health hazards are dependent on reliable quantitative measurements. Moreover improved access to high quality environmental information would enhance educational eVorts. The need for interdisciplinary co-operation and expertise in conducting eVective environmental and biological monitoring programmes arises because of the inherent complexities of how hazardous agents are dispersed and of their impact on living organisms. We therefore invite submissions from individuals or groups working in one or more of the following relevant sectors natural sciences; life sciences; geography; environmental sciences; engineering; toxicology; epidemiology; occupational hygiene; environmental occupational or public health; the socioeconomic sciences; and the regulatory community. The challenge for JEM will be to become an eVective multidisciplinary resource by attracting high quality publications from this diverse and broad community and to establish a similarly widespread readership. It is hoped that these eVorts will promote and encourage research and training thereby generating and disseminating information that will help to safeguard and preserve our environment. On behalf of the Editorial Board Evert Nieboer Chairman

ISSN:0960-7919    

DOI:10.1039/em99001n

出版商:RSC    

年代:1999

数据来源: RSC

摘要:

2N J. Environ. Monit. 1999 1 Editorial Board Members Professor Evert Nieboer (Chairman) Evert Nieboer was born in 1940 in the Netherlands and completed his undergraduate degree (Honours Chemistry) and MSc (Analytical Chemistry) at McMaster University Hamilton Canada. His doctoral work (Inorganic/Analytical Chemistry) was conducted at the University ofWaterloo Canada. He spent two years as a National Research Council (Canada) Post-Doctoral Fellow with R. J. P. Williams at Oxford. It was there that his enduring interest in inorganic biochemistry began. In 1970 he joined the Chemistry Department at Laurentian University Sudbury Canada. During his ten-year tenure at Laurentian he worked in close collaboration with D. H. S. Richardson on the use of lichens and mosses in pollution monitoring.It was his training in analytical chemistry and growing interest in biological monitoring that allowed Professor Nieboer to begin a collaboration with the medical department of a local nickel mining/ refining company. This association sparked his lasting involvement in the human and environmental toxicology of metals and metalloids. In 1980 he was appointed Professor of Toxicology in the Biochemistry Department at McMaster University in support of the Occupational Health Programme. Since July 1997 Professor Nieboer also has assumed a part-time position (Professor II Enviromental Medicine) at the Institute of Community Medicine University of Tromsø Tromsø Norway. ProfessorNieboer is an enthusiastic teacher.His teaching involvements at McMaster have included undergraduate biochemistry toxicology at the undergraduate graduate and diploma levels and tutoring in the undergraduate medical programme.Through international workshops and participation in international conferences he has promoted the application of this approach to learning to environmental and occupational health studies. Professor Nieboer’s research interests focus on the biochemistry clinical/ analytical chemistry and toxicology of metals within the context of environmental and occupational health. He has published some 100 papers and edited two books.He has led a number of teams (including physicians and epidemiologists) in the preparation of health assessment documents toxicological profiles of environmental contaminants and numerical health-risk estimations for government and industrial agencies.More recently he headed an international teamin an assessment of reproductive and developmental health in relation to occupational exposure in nickel refineries located in the Kola Peninsula of Russia.ProfessorNieboer was the Scientific Programme Chairman or Co-chair for the followingmeetings The Fourth (1988,Helsinki Finland) and Fifth (1992 Sudbury Canada) International Conferences onNickel Biochemistry Toxicology and Ecologic Issues and the First (1991 Leon Norway) the Second (1994 Leon Norway) and the Third (1997 PortDouglas Australia) International Symposium on Speciation of Elements in Biological Enviromental and Toxicological Sciences. Dr Richard Brown Richard Brown is an environmental chemist with an international reputation in developing and applying analytical methods for assessing air quality.He is a senior member of the Environmental Measurement Group of the Health and Safety Laboratory. The Group provides analytical services consultancy and training in air quality assessment particularly for organic vapours and other industrial and environmental chemicals and also provides a similar service for pesticide residue analysis in vegetation and other environmental matrices. He is a member of many European and international committees particularly on standards. Richard is a Fellow of the Royal Society of Chemistry. Dr Brown gained a BA(Hons) in Natural Sciences from the University of Cambridge in 1965 gaining anMA from the University of Cambridge and anMSc inMolecular Enzymology fromthe University ofWarwick in 1966. He gained a PhDin Molecular Sciences at the University ofWarwick in 1969 and from 1969–1970 was a Postdoctoral Fellow at the University of Trondheim.He was then Research Fellow in Botany at the University of Durham from 1970–1972.From1972 to 1975 he was Research Fellow in Biology at the University of Bradford.He joined the (then) Occupational Hygiene and Medicine Laboratory in 1976. Dr Brown was Secretary of the IUPAC Commission on Atmospheric Chemistry from 1995 and Convenor of CEN/TC264/WG11 1995 and Convenor of ISO/TC146/SC2/WG4 1997. Dr Emile De Saeger Dr De Saeger is the Senior Researcher and Head of the European Reference Laboratory of Air Pollution (ERLAP) at the Environmental Institute of the Joint Research Centre in Ispra Italy. ERLAP was established in 1994 in the framework of an agreement between the Environment Institute and DGXI to undertake activities to support the implementation of EC Air Quality and Emission Control Directives.His main tasks concern the coordination of study projects dealing with preparatory work in support to the development of new regulations; harmonisation of air quality measurements in the EU monitoring J. Environ. Monit. 1999 1 3N d’Hygie�ne et d’Epide�miologie of the Belgian Ministry of Public Health. From 1989 to 1993 he was Fellow Researcher at the Central Laboratory of Air Pollution (CLAP) Environment Institute of the Joint Research Centre in Ispra in charge of activities in support of the European Commission (DGXI) for the implementation of EC Air Quality Directives. Dr De Saeger has published approximately 20 papers or EUR reports) 20 technical reports and 25 conference proceedings.Emphasis is on air quality measurements validation of mathematical models monitoring methods development and validation QA/QC and harmonization of measurement techniques. validation and application of advanced urban pollution models; participation in global air quality monitoring programmes; emissions of dioxins and heavy metals from waste incinerators; participation in the ISO and CEN activities for the standardization of air quality measurements. Dr De Saeger gained a Licence en Sciences Chimiques and a Licence Spe�ciale en Environement from the Universite� Libre de Bruxelles in 1974 and 1979 respectively. He then spent a 6-month training period at the Commission of the European Communities (CECA). From 1977 to 1989 Dr De Saeger was Fellow Researcher at the Institut networks; development and validation of new monitoring techniques; organisation of pilot studies and measurement campaigns; interpretation and cartography of air pollution data; Dr Hendrik Emons Hendrik Emons is Head of the Environmental Specimen Bank at the Research Center Ju� lich.He studied chemistry at theMartin- Luther University of Halle where he gained a PhD in Physical Chemistry and Electrochemistry in 1984. He moved to the Analytical Centre at theUniversity of Leipzig to gain aDSc in Analytical Chemistry in 1988. He was Docent for Analytical Chemistry at the University of Leipzig. In 1991/2 hewasHumboldt Fellow and Visiting Professor at the University of Cincinnati,USA. Since 1993 he has been at the Institute of Applied Physical Chemistry Research Center of Ju� lich.Since 1996 he has also been an external member of the Chemistry Faculty at the University of Essen. He was visiting Professor at the Karl-Franzens University of Graz Austria in 1997. His research interests are analytical chemistry fromelectroanalysis and sensors to speciation; physical chemistry from surfactants tomolecular interfacial structures; and environmental chemistry fromenvironmental analysis to biomonitoring and specimen banking. He is a member of the following groups and societies Society of German Chemists (GDCh) Division of Analytical Chemistry Division of Applied Electrochemistry Personal Member of the Discussion Group ‘Environmental Analysis’;Working Group ‘Micro and Trace Analysis of Elements’; German Society of Chemical Engineering (DECHEMA) Member of the Advisory Board for ‘Chemical Sensors’; Association of Electrochemical Research Institutions (AGEF) —Board Member Speaker of the Research Topic ‘Fundamentalics’; Advisory Group ‘Analysis of Biological Material’ of the German Research Society (DFG) within the Programme ‘Human Biomonitoring’; International Society of Electrochemistry (ISE).Dr Emons is a member of the Advisory Board of T he Analyst and Analytical Communications. Professor Jan-Olof Levin Professor Levin is Head of the Department of Chemistry National Institute forWorking Life Umea° Sweden. Professor Levin gained a BSc in chemistry at the University of Uppsala in 1969 and a PhD in organic chemistry at the University of Umea° in 1974. He became Associate Professor in analytical chemistry at the University of Umea° in 1986 and Professor of chemical occupational hygiene at the University of Umea° in 1997.From 1968 to 1970 Professor Levin held various lecturing and research positions at the Department of Organic Chemistry University of Uppsala. From 1970 to 1975 he held lecturing and research positions at the Department of Organic Chemistry University of Umea°. From 1975 Professor Levin was senior research chemist at the Swedish National Institute of Occupational Health (SNIOH) later National Institute forWorking Life (NIWL) Umea°. He became Head of the Department of Chemistry NIWL Umea° in 1994. Professor Levin’s research areas are Development of methods for sampling and analysis of chemical substances in work-room ambient and in-door air; Development of methods for measuring chemicals or metabolites of chemicals in human body fluids; and Assessment of chemical exposure within various branches of industry.Professor Levin has published more than 200 papers reports and abstracts within the above mentioned areas. 4N J. Environ. Monit. 1999 1 Dr Yngvar Thomassen Dr Yngvar Thomassen was born in Porsgrunn Norway on March 25 1947. Dr. Thomassen’s academic training was obtained in the Department of Analytical Chemistry at the University of Oslo from where he graduated in 1973. He spent one year at the Norwegian Defence Institute before taking a postdoctoral research associate position at the Department of Analytical Chemistry at the University of Oslo where he conducted research for 2c years. In 1978 he visited The University of Toronto Department of Environmental Studies and Geology for one year with a Royal Norwegian Grant (visiting scientist).He is currently Director of Research at the National Institute of Occupational Health in Oslo where he has spent 23 years of his professional life. Dr. Thomassen is the author or co-author of over 150 scientific publications on atomic spectroscopy and other spectroscopic methods for the determination of essential and toxic elements in the environment with special emphasis on electrothermal atomic absorption spectrometry (ETAAS). He is best known for his research on the use of ETAAS in the determination of selenium and other toxic elements in human health and disease. Dr Thomassen serves on the Editorial Boards of T he Analyst and Analytical Communications Journal of T race Elements in Medicine and Biology and he has given over 170 presentations on various aspects of his research of which 56 were invited lectures at major conferences and symposia.In the period 1983–91 he was a member of the Commission on Toxicology International Union of Pure and Applied Chemistry (titular member from 1986) where he initiated the development of human body fluids as quality assurance materials for the measurement of minor trace and ultratrace elements and organic metabolites. Dr Thomassen has organized a number of Nordic national and international conferences on topics dealing with analytical chemistry atomic spectroscopy and environmental and biological issues. His present research focuses on clinical aspects of analytical chemistry and the application of atomic spectroscopy (ETAAS and ICP-AES) within the context of environmental and occupational health.Philippe Quevauviller was born in 1959 in Chatelaillon-Plage (France). He studied marine geology at the University of Bordeaux I (France) and specialised in geochemistry for which he obtained an MSc in 1984. Between 1984 and 1987 he was associate researcher at the Portuguese Environment Ministry where he performed a multi-disciplinary study of a coastal and estuarine environment (Sado estuarine system Portugal) dealing with its characterisation in terms of geomorphology sedimentology and geochemistry. Geochemical studies of the Sado Estuary were pursued in 1987 in particular on trace metals and organotin patterns in collaboration with the Laboratory of Analytical Chemistry of the University of Pau (France).He performed other studies at the end of 1987 in collaboration with the ‘Laboratoire Municipal’ of Bordeaux (France) to gain experience in the determination of PCBs in sediment and soil samples. From January 1989 to March 1989 Philippe Quevauviller was Associate Researcher at the Dutch Ministry of Public Works (Rijkswaterstaat The Netherlands) for which the research activities focused on the evaluation of contamination levels in Dutch coastal environments for organotin compounds; this work included sampling of various environmental compartments (sediments water and suspended matters) in Dutch estuaries and the North Sea followed by laboratory work (determinations of butylated tin compounds) carried out at the Laboratory of Molecular Photophysics and Photochemistry of the University of Bordeaux I (France).Parallel research activities were carried out on organotins and methylmercury e.g. on grain size distribution sediment studies contamination studies of estuarine and lagoon areas (e.g. Arcachon Basin in France) leaching studies of PVC with respect to butyltin compounds etc. Since 1989 he has been managing RTD projects in the frame of the Standards Measurements and Testing Programme (formerly BCR) of the European Commission. These projects generally concern the certification of environmental analysis and pre-normative research aiming to test the feasibility of European standards prior to their implementation. He has organised a series of EC scientific workshops dealing with various topics in order to stimulate the creation of European networks for the improvement of the state-of-the art of various types of analytical activities and he has participated in the scientific committees of various international conferences. He has published more than 140 papers 45 EUR reports and one book on ‘‘Method Performance Studies for Speciation Analysis’’ (published by The Royal Society of Chemistry); he has also acted as editor or co-editor of 15 special issues of international journals and of 4 books. He is Editor of the Measurement & Testing Newsletter (Information bulletin of the EC-SMT programme) member of the editorial boards of Analysis Europa the Fresenius’ Journal of Analytical Chemistry Quimica y T ecnologia Medioambiental Journal of Analytical Atomic Spectrometry and contributing editor to T rends in Analytical Chemistry. Dr Philippe Quevauviller (DG XII Liaison Member)

ISSN:0960-7919    

DOI:10.1039/em99002n

出版商:RSC    

年代:1999

数据来源: RSC

摘要:

makers and researchers has increased dramatically. For scientists it has brought increased budgets at a time of increasing pressure on research funding. For politicians it has brought yet another highly contentious environmental issue crucially dependent on scientific data. Into the mainstream From the UK’s consultation paper in January to the European Commission working paper in December 1998 saw a whole series of policy documents and action plans that signalled EDs had moved to the centre of the environmental stage. In the US the Endocrine Disrupter Screening and Testing Advisory Committee (EDSTAC) a committee of 40 scientists and policy-makers set up by the EPA presented its long-awaited strategy last October.2 EDSTAC called for a comprehensive screening and evaluation programme to identify Rising hormones Nineteen-ninety eight was a frantic year in the hormone-disruptor debate with a whole series of studies and initiatives pushing the hormones issue up the policy agenda.As policy-makers weigh the options the environmental monitoring community has an important opportunity to shape future policies. Over recent years concern has arisen over whether exposure to small amounts of man-made chemicals can interfere with the hormonal—or endocrine— systems of humans and animals (see Box 1). The debate on ‘endocrine disrupters’ (EDs) has been notable for the wide range of chemicals implicated the complexity of the supposed interactions and the very low dose levels involved.Although scientific research has been undertaken for some time hormone disrupters only really appeared on the policy agenda in 1996 with the launching of the OECD’s Endocrine Disrupters Project.1 Since then the attention given to the hormones issue by both policy- Box 1 The endocrine debate The debate focuses on whether exposure to small amounts of man-made chemicals in air water and food can interfere with the hormonal systems of humans and wildlife. The endocrine system is critical to the functioning of both plants and animals controlling growth reproduction and day-to-day living. Certain external substances are believed to interact with these chemical messengers causing adverse health eVects. Laboratory studies have indicated potential harmful eVects in animals or animal cells.However there is relatively little evidence on the incidence and causes of endocrine-disrupting eVects in the environment. Abnormalities in the sexual development of fish have been observed in the UK Japan and elsewhere. Some cancers and behavioural problems are also thought to be hormone related. A wide range of substances have been reported to cause endocrine-disrupting eVects and the scope continues to expand with new research. Although some are restricted to specific applications others are widely used. As yet the nature of the interactions is not well understood but it is believed the chemicals either mimic or block the responses of endocrine receptors. In some cases the substances are long-lived and are known to accumulate in the tissues of plants and animals.Table 1 shows the main categories of substances concerned. Feature Article chemicals with hormone-disrupting potential. The programme is to address both human and ecological eVects and will examine processes related to estrogen androgen and thyroid hormones. The disrupting properties of both chemical substances and common mixtures will be considered. Altogether more than 87,000 individual chemicals are to be screened including ingredients in pesticides cosmetics and food additives. Across the Atlantic the European Parliament called for a precautionary approach to the ED issue.3 However in their report also issued in October MEPs acknowledged that firmer scientific evidence about possible health and fertility eVects is needed before substances should be removed from the market.As host to a major international conference in November the Austrian government added to the pressure by saying that action on hormone disrupters ‘is overdue’. The shape of future European policy Table 1 Substances with potential endocrine-disrupting properties Uses Examples Category Natural Phyoestrogens Present in plant materials Produced naturally Isoflavones Lignans Coumestans 17b-estradiol Female sex hormones Man-made Incineration and chemical byproducts Dioxins Polychlorinated biphenyls Polychlorinated organic compounds Organochlorine pesticides DDT; dieldrin; lindane Insecticides (some now banned or phased out) Organotins Alkylphenols Tributyltin Nonylphenol Anti-fouling agent Production of nonylphenol ethoxylates and polymers Alkylphenol ethoxylates Phthalates Bi-phenolic compounds Nonylphenol ethoxylate Surfactants Dibutyl phthalate (DBP) Plasticisers Butylbenzyl phthalate (BBP) Bisphenol-A Polycarbonate plastics and epoxy resins Synthetic steroids Contraceptives Ethinyl estradiol Adapted from Endocrine-disrupting substances in the environment What should be done? UK Environment Agency 1998 J.Environ. Monit. 1999 1 5N J. Environ. Monit. 1999 1 Feature Article became clear in the European Commission’s paper published in December.4 This outlined a series of actions as the basis for a concerted European action plan.For the short term the Commission proposes further research on the causes and consequences of hormone disruption together with full participation in international screening programmes. A priority list of potential EDs is proposed as an aid to environmental and product monitoring. This would be followed in the longer term by amendments to existing legislation. The Commission said eVective substitutes for many hormone disrupters will also need to be found or developed. A cautious response Industry understandably has been guarded in its response. At a meeting in October the German Chemical Society said that potential human health eVects of EDs were being overestimated and that the ensuing ‘panic’ was unjustified.5 Stressing that estrogenic eVects of suspected hormone disrupters have only been found under laboratory conditions the Society noted that as yet there is no proof of any causal link between these chemicals and human health.Responding to the UK consultation paper published in January,6 the Chemical Industries Association emphasised the importance of reproducible protocols before a reliable prioritisation can take place a stance reiterated by other industry bodies.7 However industry is also sensitive to charges of complacency. As evidence of its commitment it points to expenditure of around $20 million per annum on industrial research into EDs in addition to normal expenditures on product testing.8 This includes a $7 million research programme on endocrine-disruptors launched by the European Chemical Industry Council (CEFIC) last May.Under this scheme independent institutes across Europe are undertaking research into health 6N and wildlife aspects. A further initiative concerned with the North Sea coast Endocrine Disruption in the Marine Environment (EDMAR) is also receiving CEFIC support. Battle lines are drawn While the debate to date has been fairly low key there are signs of looming battles ahead. In November a coalition of eight environmental groups including the UK oYces of Friends of the Earth the World Wide Fund for Nature and Greenpeace called for immediate action to reduce the risks to health and the environment from hormone disrupting chemicals.The NGOs also proposed radical changes to the chemicals licensing system to reduce the risk of similar issues arising in the future. As the year drew to a close European industry and consumer groups clashed bitterly over the use of phthalates as softening agents in children’s toys.9 The row followed new evidence from the EU committee on toxicity ecotoxicity and the environment over the migration of phthalates used in toys. Although the concerns do not relate solely to endocrine eVects the bitter war of words was a stark reminder of what is at stake in the endocrine debate health versus competitiveness. Neither should suVer unnecessarily.Future focus From the many studies and research findings of recent years three issues are set to dominate the scientific agenda. These are the investigation of an increasingly broad range of hormonal eVects; the significance and interpretation of low-dose eVects; and the cost-eVective design of large-scale chemical screening programmes. More than sex To date public attention has focused mostly on the disruption of sex hormone systems. Recently however scientific research has widened to consider the potential eVects on other endocrine systems such as pituitary and thyroid hormones that influence growth development and behaviour. One recent study by Swedish scientists concluded that changes to the thyroid and retinoid systems could be more important than for sex hormones including possible eVects on behaviour intelligence and cancer formation.10 The ‘most probable’ eVects of human exposure to EDs according to the report are neuro-behavioural changes.Cancer formation was also considered to be a high risk including cancers of the breast endometrium prostate and testes. Based on the current evidence falling sperm counts were found to be one of the least likely eVects. Low dose mysteries One of the most controversial aspects of the endocrine debate is the extent to which very low doses can cause significant biological eVects. Dose–response relationships is one disputed area.11 Traditionally toxicologists assume that the biological response to a chemical always increases with increasing doses.Recent work at the University of Missouri reported the eVects of bisphenol and diethylstilbestrol (DES) on prostate development in male mice. Prostrate size was inhibited for high doses but actually increased for doses 10,000 times lower. Thus the dose-response curve was in the form of an inverted U and the data from the high dose part of the curve would not predict the lowdose eVects. However subsequent work sponsored by industry claims to have found no evidence of such eVects from low-dose exposures for bisphenol-A.12 Another major challenge is in dose thresholds. For all chemicals classical toxicology assumes there is a safe dose below which the body’s natural protection mechanisms prevent harm occurring.A growing body of evidence suggests that for hormonal systems there is no such threshold. EVective screening With such a large number of chemicals to be assessed researchers need to design cost-eVective screening programmes.2 The EDSTAC report proposed a tiered approach based on initial sorting priority setting Tier 1 Screening (T1S) and Tier 2 Testing (T2T). The initial prescreening programme will be automated. The scale of the exercise makes validation and standardisation of the screening tests themselves a major challenge. The main validation issues are in the Tier 1 screens a series of three in-vitro and five in-vivo tests intended to determine whether chemicals are potential endocrine disruptors.The more complicated Tier 2 tests involving mammals are well accepted and largely validated. EPA expects the entire standardisation and validation process to take at least two to three years although individual tests will be implemented as soon as they have been validated. As one of the first and most important steps towards implementation the validation process is being watched closely by industry and environmental groups. Industry is concerned that the tests are reliable representative and transparent. Environmental groups fear that industry could use the massive validation and screening programme to drag its feet on the endocrine issue. Policy implications In the policy arena future activities will focus on three main areas.Firstly research into the causes and consequences of endocrine disruption will remain a priority. Despite the extensive worldwide research eVort we still have relatively limited evidence of causal links between EDs and human health. The toxicological evidence in particular is hotly disputed. Environmental monitoring will play a major role in helping to prove or disprove these links. Secondly there is an urgent need for more information on occurrences and risks. While some substances are routinely monitored under existing legislation reliable data on the levels of many endocrine-disrupting chemicals in the environment is lacking. This means extensive environmental monitoring and product screening programmes.Thirdly and in the longer term policy-makers will be concerned with appropriate regulatory approaches. On the basis of the priority lists they will be looking to see how far the relevant chemicals are covered by existing legislation and what amendments or new regulations might be needed. In all of these areas environmental monitoring will play a very important role in advancing the hormone debate. However with such a large number of substances implicated and the technical diYculties of chemical analysis comprehensive testing will be extremely expensive. Environmental monitoring programmes need to be properly targeted and designed on the basis of environmental risk. A ‘priority list’ approach where certain substances are prioritised for detailed investigation is favoured in both the US and in Europe.In the interests of eYciency the main focus will continue to be the international screening programmes being co-ordinated by the OECD. In the meantime policy-makers face a dilemma to take early preventative action or await the results of further targeted research. Environmental groups argue for a precautionary approach establishing lists of substances that may be regarded as hormone-mimicking with a view to early legislation on emissions environmental quality standards (EQSs) and product bans. The chemical industry argues that it is only possible to draw up target lists once there is international agreement on selection criteria which will not be in place until at least 2000.Most regulators seem to favour a middle way establishing priority lists for monitoring but stopping short of legislative action. A challenging agenda At a technical level hormone disruption presents a long and challenging agenda for the environmental monitoring community. Specific priorities for the analytical sciences include the development of $ standard and cost-eVective screening tests of ED activity for diVerent chemicals; $ methods for assessing ED eVects of chemical mixtures as the basis for toxicity-based controls of environmental discharges; $ biological methods for assessing direct eVects in environmental monitoring and surveillance programmes; $ analytical methods for detecting low concentrations of substances in environmental media.In addition the analytical sciences will have a role in $ investigating the interactions of chemicals with endocrine systems; $ investigating the fate and transformation of ED chemicals in environmental media. This applies particularly to water suspended particulates sediments and soils and to wastewater treatment processes; $ generating information for the development of EQSs that take account of ED eVects; $ improving the basis for risk assessment for diVerent categories of substances. The results of this work will influence the direction and pace of regulation and will be eagerly awaited on all sides. The stakes are high for all concerned policy-makers industry and NGOs.As so often in Feature Article science the researchers themselves could be caught in the middle with every paper and research report fought over and the data interpreted or misinterpreted to suit the argument. While the debate to date has been fairly well natured there are no guarantees it will remain so. Indeed there are all the signs of a classic industry-environmentalist confrontation looming. So while scientists should welcome the increased budgets they should be aware of the dangers in rising hormones. Mike Sharpe 7N J. Environ. Monit. 1999 1 Notes 1 Details at www.oecd.org/ehs/ endocrin.htm 2 EDSTAC Final Report Endocrine Disruptor Screening and Testing Advisory Committee Environmental Protection Agency Washington D.C. 1998. Available at www.epa.gov/opptintr/opptendo/ whatsnew.htm 3 ENDS Daily 21st October 1998 (see www.ends.co.uk) 4 Working paper on hormone disrupting chemicals European Commission DG XI Brussels December 1998 5 ENDS Daily 1st October 1998 (see www.ends.co.uk) 6 Endocrine-disrupting substances in the environment What should be done? Environmental Issues Series No.1 Environment Agency Bristol UK 1998. Available at www.environment-agency.gov.uk 7 Response to the Environment Agency Consultative Report ‘Endocrine-disrupting substances in the environment What should be done?’ Chemical Industries Association London 1998 9 Details available at www.cefic.be/emsg/emre/ emre-en.htm 9 ENDS Daily 1st December 1998 (see www.ends.co.uk) 10 Endocrine disrupting substances Report 4859 Swedish Environmental Protection Agency Stockholm 1998. Available at www.environ.se 11 ‘Results of low-dose exposure research may challenge the theoretical basis of toxicology’ Environmental Science & Technology 1st November 1998 12 Details available at www.bisphenola. org/bulletin2.html

ISSN:0960-7919    

DOI:10.1039/em99005n

出版商:RSC    

年代:1999

数据来源: RSC

摘要:

News Legislation US revises drinking water regs New measures to strengthen drinking water protection were announced by US President Bill Clinton in December. Revisions to public health standards issued under the Safe DrinkingWater Act (SDWA) Amendments of 1996 will protect against cryptosporidium other disease-causing microbes and potentially harmful byproducts of the water treatment process. The new rules arise because certain microbial pathogens such as cryptosporidium are known to be highly resistant to traditional disinfection practices. Over recent years cryptosporidiosis outbreaks have been reported across the United States resulting in intestinal illnesses and at least 50 deaths. Water suppliers have to provide suYcient protection against microbes but avoid other health risks from disinfection byproducts (DBPs).These are the first of a series of technical regulations being prepared under the SDWA Amendments to be phased in by May 2002. They follow six years’ work by US water industry environmental and public health groups and local state and federal authorities. EPA Safe Drinking Water Hotline T el +1 800 426 4791 EPA OYce of Ground Water and Drinking Water www.epa.gov/OGWDW/ Germany takes the EU helm Germany has brought a long environmental agenda to its six-month presidency of the European Union which started in January. The high profile being given to environmental aVairs follows the victory of the Social Democrat-Greens coalition in last year’s general election. Pride of place goes to proposals for higher energy taxes as a means of cutting employment charges and achieving climate change objectives.These follow similar measures within Germany itself. Other priorities identified for the German presidency include a framework law on water resources and protection revision of regulations on 8N J. Environ. Monit. 1999 1 air emissions from waste incinerators and electric power plants and emission standards for heavy goods vehicles. German environment ministry www.bmu.de EU to cut benzene and CO pollution Plans to clean up Europe’s air by imposing strict limits on emissions of benzene and carbon monoxide have been approved by the European Commission. The plans require benzene levels to be cut by 70% to 5 mg m-3 by 2010 and CO to be reduced by a third to 10 mg m-3 by 2005. Welcoming the new measures EU Environment Commissioner Ritt Bjerregaard said the targets were ambitious but attainable.If approved the proposals will force EU Member States to prepare action plans to tackle pollution hot spots. Under the Auto-Oil programme approved last June EU governments are already obliged to cut benzene levels in motor fuels and restrict the amount of CO in vehicle exhausts. The new limits may require further measures such as alternative fuels road use charges traYc abatement schemes and industrial pollution controls. The limits will be reviewed in 2004 and measures against other airborne carcinogens are expected later in the year. Devolution in air toxics legislation Proposals issued by the EPA will allow state and local agencies greater autonomy in implementing air pollution control programmes. Introduced under the Clean Air Act the proposed regulation allows state and local governments to administer and enforce their own regulations for reducing air toxics in place of federal programmes.While states are already allowed to introduce their own toxics regulations the new rules will allow federal and state authorities greater flexibility in meshing their schemes together. This should reduce the administrative burdens on industry and government by eliminating overlapping federal and state regulations. EPA OYce of Air Quality Planning and Standards www.epa.gov/ttn/oarpg Phased approach proposed for emissions register The forthcoming European Polluting Emissions Register (EPER) could be introduced in three stages according to the Swedish Environmental Protection Agency. Known greenhouse gases sulfur dioxide and ammonia are proposed for inclusion in the first phase.This could be followed by benzene asbestos and some known heavy metals. The final phase could incorporate long-lived organic substances to be phased out within 25 years. EPER is a direct result of the EU’s Integrated Pollution Prevention and Control (IPPC) Directive which aims to strengthen the European framework on industrial pollution controls. The register is to provide a coherent system for reporting from all significant point sources to air water and soil every three years. The information will be available both to decision-makers and the public. Under the Swedish proposals the register would be compiled and maintained by the European Environmental Agency in Copenhagen. Swedish EPA www.environ.se Ireland faces challenge on air quality; finalises IPC system The continuing growth in road traYc threatens to reverse Ireland’s progress in improving air quality according to the Irish Environmental Protection Agency.In its air quality report for 1997 published late last year EPA notes that actions against traditional pollution sources such as industrial stacks have successfully reduced ambient levels of smoke and sulfur dioxide. However, levels of other pollutants such as nitrogen dioxides and particulates (PM10) are close to legal limits and will pose problems in complying with EU legislation. The new pollutants are a consequence of the increases in road traYc arising from Ireland’s rapid economic growth. As part of measures to tackle the problem a major review and restructuring of the country’s air quality monitoring network is to be undertaken.Meanwhile the recent introduction of new licensing requirements for a further 20 types of businesses has completed the introduction of integrated pollution control (IPC) in J. Environ. Monit. 1999 1 9N Environmental quality News Ireland. First introduced in 1994 the IPC system is modelled on the British system and covers around 100 sectors and processes. The latest additions include large combustion plants and certain agricultural activities. Irish EPA www.epa.ie Italy toughens air quality standards New measures aim to combat air pollution in Italian cities. Under a decree that came into force on 1st January this year benzene limits are set at 10 mg m-3 for cities with populations greater than 150 000. Smaller towns with large numbers of tourists and areas at high risk of pollution are also covered by the new limits.Under the regulations city mayors are required to report on urban air quality with specific reference to benzene levels and pollution sources by this May. Motor scooters are major contributors to benzene in Italian cities and the new measures allow the authorities to prohibit scooters failing EU emissions standards. Italian Environment Ministry T el +39 06 57221 EPA moves against mercury and toxic chemicals Concerted action against mercury and other priority chemicals such as dioxin and PCBs is planned under a draft strategy released by the US EPA. The strategy targets persistent organic compounds and others such as mercury that can ‘bioaccumulate’ or build up in the food chain. Under the strategy EPA will develop and implement national action plans for persistent chemicals that utilise a mixture of voluntary action regulation enforcement and new research.Further persistent pollutants will be screened with a view to developing reduction plans and mechanisms will be developed for preventing potential new pollutants reaching the marketplace. The progress of all actions will be closely monitored. While public comments are being invited on the current draft strategy EPA is already implementing the first of the initiatives—an action plan for mercury. Action plans for other chemicals will be developed during the course of the year. Under the mercury action plan electricity utilities are to be required to publish information on mercury emissions from coal-fired power stations.These are the largest source of mercury emissions in the US accounting for one third of all manmade emissions. Commenting on the move EPA Administrator Carol Browner said community right-to-know initiatives were ‘one of the most eVective tools to solve tough environmental problems’ allowing people to make ‘informed decisions‘ about how they live and work. The new rules apply to all plants above 25 MW around 1400 in all including random smokestack testing for a sample of 75 plants. EPA began collecting the emissions data on 1st January and will make it available on the Internet from early next year. Air toxics strategy ppic@epa.gov Mercury action plan maxwell.bill@epa.gov Performance reviews highlight water problems France and Belgium both face major challenges in tackling water pollution according to two recent environmental assessments.Reviewing Belgian environmental performance the OECD notes that the country’s high population density strong industrialisation and intensive agriculture place strong pressures on water resources. The report notes that standards of waste water treatment are amongst the lowest in the OECD and that progress in dealing with agricultural pollution has been limited. Consequently Belgium faces ‘a major challenge’ in implementing EU directives on nitrates and urban waste water the report concludes. Water pollution by nitrates is also on the increase in France according to a report from the French environment institute IFEN. Over two-thirds of the country are said to be experiencing increases in nitrate levels with particular hot spots in parts of northern France.Along with other EU states France has already been threatened with legal action by the European Commission unless nitrate levels are reduced. Other common themes in the reports include the concerns expressed regarding urban air quality waste management practices and the destruction of wetlands in the two countries. OECD www.oecd.org IFEN www.ifen.f r Japan sounds alarm on hormone disrupters Recent results from Japanese researchers raise further concerns about the health and environmental eVects of hormone-disrupting chemicals. A team at Yokohama City University led by Taisen Iguchi found evidence that hormone disrupters can enter the brain and be passed onto foetuses. Injecting the plastic additive bisphenol-A into pregnant mice the team measured increases of the chemical in the brains of both adults and foetuses.The findings suggest that the compounds can cross the protective barriers of the placenta and enter the brain liver and other organs. In a separate development the Japanese Environment Agency has found that nine out of ten of the country’s waterways are contaminated with hormone-disrupting chemicals. A survey of 130 rivers lakes and marine locations found up to 11 such chemicals at 93% of the sites sampled. The commonest pollutants were nonyl phenol found in 76% of sites tested bisphenol-A recorded in 68% of waterways and di(2-ethylhexyl) phthalate found at 55% of sites. Further work is planned to fully assess the results and their implications. More information on endocrine disrupters is given in the Feature Article (p.5N) in this issue. EPA reviews MTBE in gasoline The US EPA has set-up a panel of leading experts to advise it on the use of MTBE (methyl tertiary butyl ether) and other oxygenates in gasoline. While these compounds have brought important clean air benefits EPA says a better understanding is needed of the public health concerns raised by the discovery of MTBE in some water supplies. The panel brings together leading experts from public health petrochemicals water utilities and local and state governments under the chairmanship of Dr. Daniel Greenbaum President of the Health EVects Institute Cambridge MA. They will examine the role of oxygenates in meeting clean air goals and assess evidence on their health and environmental eVects. Production costs of oxygenates and potential alternatives will also be studied.Clean air takes to the web Clean air information will be published daily on the Internet under recent moves by the US EPA to give citizens clearer information about pollution levels in their local communities. The proposal for a new national website on air quality data is part of a package of measures to revise the Agency’s Pollutant Standards Index (PSI) also known as the Air Quality Index. The PSI provides environmental agencies with a uniform system for measuring pollution levels for major air pollutants on a scale from 0 (good) to 500 (hazardous). Under the proposals an additional air quality category of ‘unhealthful for sensitive groups’ will be added just above the health standard 100. The new category will provide a warning for asthmatics and others with respiratory problems.In another right-to-know measure EPA has opened up a database of air emissions and fuel sources for virtually all US power plants. Integrating 12 diVerent federal databases the new Emissions and Generation Resource Integrated Database or ‘E-GRID’ provides information on emissions per unit of electricity permitting direct comparisons of pollution levels from diVerent power sources. Pollutant data initially covers emissions of carbon dioxide sulfur dioxide and nitrogen oxide for 1996 but more pollutants will be added in the future. With 18 states already allowing consumers to chose between competing electricity suppliers EPA considers this information an important aspect of the citizen’s ‘right-to-know’. It will also allow regulators to monitor changes within the electricity industry.PSI stone.susan@epa.gov E-GRID www.epa.gov/acidrain/ egrid/egrid.htm Stronger action urged on pesticide residues High levels of pesticide residues in fruit and vegetables have been highlighted in the first EU-wide survey. Looking at seven pesticides the survey found the highest residue levels in lettuce followed by grapes strawberries apples and tomatoes. The commonest residues were dithiocarbamate fungicides and pesticides of the benomyl group. Commenting on the data EU Consumer Safety Commissioner Emma Bonino said that Member States should respect maximum residue levels and called for stronger action to ensure this was the case. The Commission says the pesticide residue survey will now be undertaken annually. Agency reports improvement in bathing water The proportion of coastal bathing waters meeting EU standards reached more than 90% for the first time last year according to the UK Environment Agency.The figures are contained in the Agency’s 1998 survey of bathing water in England and Wales. Of 458 coastal bathing waters 413 (90.4%) met the mandatory coliform standards specified in the Bathing Waters Directive compared with 88.8% in 1997. Water quality was also measured at nine inland bathing waters for the first time. EA www.environment-agency.gov.uk Eco-farming increases heavy metals Researchers in the Netherlands have found that some systems of ecological arable farming which use only organic fertilisers contaminate the soils with heavy metals. Levels of cadmium copper and lead were up to twice as high as when a combination of both animal manure and artificial fertiliser is used.The scientists also found that mixed farming combining arable with dairy farming leads to less heavy metal contamination than farming based on only one of these. To avoid discriminating against ecological practices in the future soil quality norms should be based on the total heavy metals load the researchers say. Dr. Simon Moolenaar SWM@rotterdam.iwaco.nl 10N J. Environ. Monit. 1999 1 News Chemical hazards Experts prepare for global treaty on POPs The prospect of a global treaty on persistent organic pollutants (POPs) moved a step nearer following a recent meeting of international experts. The UNEP Criteria Expert Group discussed scientific criteria for identifying suspected POPs which pose a risk to human health or the environment.The work of the Group will form the scientific basis for a global treaty on POPs to be adopted by next year. Twelve POPs are already being addressed by the treaty negotiations— aldrin chlordane DDT dieldrin dioxins endrin furans heptachlor hexachlorobenzene mirex PCBs and toxaphene. In addition to toxicity the Group considered factors such as volatility persistence long-range transport and bioaccumulation. Speaking after the meeting in Bangkok late last year Group Co-Chair Fatoumata Jallow Ndoye said ‘We were very pleased by the progress. There are draft proposals for POPs criteria and a process for adding chemicals to the future treaty. We also have a proposal for integrating socioeconomic considerations into the process.’ UNEP Executive Director Klaus Toepfer said ‘The attention paid by countries from all parts of the globe attests to the seriousness of the global POPs problem and bodes well for successfully concluding negotiations by the year 2000’.UNEP jwillis@unep.ch http://irptc.unep.ch OECD agrees chemicals criteria Users will have clearer information on the risks from chemicals following international agreement on a harmonised classification system. Meeting in Paris late last year the OECD Chemicals Committee agreed on a common system for classifying chemicals according to their toxic and ecotoxic properties. A chemical’s hazards are to be classified against eight criteria acute toxicity carcinogenicity skin irritation/ corrosion eye irritation/corrosion sensitisation germ cell mutagenicity reproductive toxicity and aquatic environment.OECD says that as well as aiding eVective communication the new system will eliminate barriers to trade from diVerent classification and labelling systems and reduce the need for animal testing. The system grew out of the Rio Conference in 1992 which requested that a global classification and labelling system for chemicals be developed. Work is not finished yet however. The outline scheme is being passed on to the Inter-Organisational Programme for the Sound Management of Chemicals a UN body which will work out operational details. Full implementation is expected by 2001. OECD ehscont@oecd.org Millennium bug could lead to chemical accidents Many chemical installations and storage facilities risk accidents as a result of the millennium computer bug a group of international hazards experts has warned.At its meeting in Paris in December the OECD’s Working Group on Chemical Accidents noted that although some chemical companies are already ‘Year 2000 compliant’ many others are still at risk. Small and medium-sized companies which generally have lower awareness are a particular concern. The computers responsible for the maintenance schedules monitoring and control and security systems in modern chemical plants are potentially vulnerable to Y2K failures. Facilities at risk include oil refineries petrochemical plants and hazardous goods transportation. The Group called for greater co-operation between governments and the chemical industry in addressing the problem including in developing countries. For those still struggling with the problem the OECD’s Electronic Information Clearing House on Chemical Emergencies can provide access to relevant information.The system routes all enquiries about the millennium bug and hazardous installations to designated contact points. OECD ehscont@oecd.org EU reviews chemicals controls A major overhaul of EU controls on dangerous chemicals has been recommended by the European Commission. Reviewing the existing regulatory framework on chemicals the Commission says urgent revisions are needed to reflect growing public concern and emerging knowledge. The Commission is particularly keen to address ‘new’ issues such as hormone disrupters and what it calls ‘structural deficiencies’ in chemical risk assessment. As well as new measures based on the precautionary principle the Commission is calling for more rigorous and consistent implementation and enforcement of regulations by Member States.Evaluation procedures and communication with the public also need to be improved. Formal legislative proposals are likely to follow as part of a new strategy for chemicals to be presented later this year. Global action on HFCs Action to reduce emissions of hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs) is being investigated by parties to the Montreal Protocol. Both chemical groups are powerful greenhouse gases but are being used as substitutes for substances that deplete the ozone layer. A meeting convened by the UN Environment Programme in Cairo last November invited a committee of experts to examine ways to minimise the use of HFCs and PFCs. The committee is expected to report before the end of the year.UNEP www.unep.ch/ozone Global ban on TBT The use of organotin antifouling paints will be banned from 2003 under a draft agreement reached by members of the International Maritime Organisation (IMO). The agreement now has to be incorporated into a legal instrument which is likely to receive formal approval by the end of the year. Other measures confirmed by the IMO include proposals to ban organotin paints from use on any ship by 2008 and procedures for evaluating the environmental eVects of nonorganotin antifouling paints. Organotin paints such as tributyl tin have been shown to damage shellfish and these latest measures are part of a movement to remove them from the marine environment. IMO www.imo.org Australia assesses chemical infrastructure Environment Australia has published what it calls a ‘national profile‘ of the country’s chemicals management infrastructure.Descriptive rather than discursive the report draws together information from government industry community and research bodies to provide the first comprehensive overview of chemical management practices. A number of barriers to accessing information on chemicals use or emissions are identified in the report. Many of these are already being addressed by the recent introduction of the National Pollutant Inventory. Further measures are likely following the emphasis given to environmental issues and especially chemicals in the recent general election. Full report at www.environment.gov.au/epg/pubs/ profile.html J. Environ. Monit. 1999 1 11N News Chemicals database will aid emissions scenarios Two new information sources on industrial chemicals have been announced by OECD.The Database on Use and Release of Industrial Chemicals provides chemical information as an input to 12N J. Environ. Monit. 1999 1 Directory describes the schemes used to notify and assess the use of new chemicals in OECD countries. The directory is part of work to make the diVerent national schemes more transparent. OECD ehscont@oecd.org environmental exposure analyses. Users can search the database for published information on emission scenarios specific chemicals or specific applications. OECD says the database will help avoid duplication of eVort in developing chemical emission scenarios. A second database the New Industrial Chemicals Information News Research news FP5 gets the green light The European Union’s Fifth Framework Programme has finally received the go-ahead after nearly a year of impasse between the European institutions.The Council of Research Ministers representing the EU member governments gave the final approval for the programme at its meeting in December allowing the start as scheduled at the beginning of the year. The main sticking point had been a dispute between the European Parliament and the European Commission the EU’s executive arm about the budget. The parties agreed on a budget of Euros 15 billion for the four year programme. Under the new arrangements research activities related to environmental monitoring and standards formerly undertaken under the Standards Measurement and Testing Programme will be split across a number of ‘research themes’.The first calls for proposals are expected in February or March this year. For further details on the Fifth EC-Framework Programme see page 16N. EU R&D www.cordis.lu Canada and US focus on hormone disrupters The Canadian federal government is to invest CAN $40 million into research on endocrine disrupters and other toxic substances. The initiative fulfils a commitment under the renewed Canadian Environmental Protection Act for research on hormone disrupting substances. Other health and environmental issues being addressed under the fouryear package include persistent organic pollutants toxic metals cumulative eVects of toxics and air pollutants. The programme will be implemented under Canada’s Toxic Substance Research Initiative (TSRI). Across the US border the National Toxicology Program and the National Institute of Environmental Health Sciences are setting up a Center for the Evaluation of Risks to Human Reproduction (CERHR).The new Center will provide a focus for the two organisations’ work on the eVects on chemicals on human reproduction and development. It is being operated under contract by Sciences International Inc. As well as the scientific community NTP says the Center will make a special eVort to reach out to those who are not scientifically trained. Inputs will be solicited from a wide range of interest groups and the Center’s reports will be available on the Internet. Chemicals for potential evaluation are currently being invited together with candidates for the Center’s list of expert reviewers. T SRI www.hc-sc.gc.ca/tsri NT P http://ntp-server.niehs.nih.gov/ EU launches new health institute A new Institute for Health and Consumer Protection has been launched by the EU’s Joint Research Centre.The Institute will support the European Commission in policymaking on health and consumer issues. It will provide a focus for the Centre’s work on standards and quality controls in areas such as food cosmetics drugs and chemicals. Acting Director Herbert Allgeier said the new Institute was part of the EU’s eVorts to ensure that ‘the consumer is not deceived by counterfeit or adulterated products or exposed to unnecessary risks and hazards’. Specific activities will include assessments of the health eVects of environmental contaminants; creating and maintaining databases on chemical risks; and assessing compliance of foodstuVs with quality and product labelling regulations.JRC www.jrc.org Secondment Programme for EU scientists The EU’s Joint Research Centre has launched a new programme of scientific exchanges. The Secondment Programme encourages scientists from industry or other research institutes to work within the JRC on a temporary basis. The JRC helps the European Commission to frame science-based regulations and policies. The secondments are an opportunity for researchers to get an inside track on policy-making and will also aid training and the transfer of know-how. JRC institutes and programmes covered by the scheme include the Centre for Reference Materials and Chemical Reference Measurements the Reference Laboratories for Neutron Data and for Isotopic Measurements and the European Reference Laboratory for Atmospheric Pollution.JRC www.jrc.org Annual date for asthma ‘Help our children breathe’ was the theme of the first World Asthma Day on 11th December. With an estimated 150 million people worldwide facing daily struggles against recurrent asthma attacks World Asthma Day will be an annual event to highlight the plight of asthma suVerers. The theme reflects particular concern over the increasing incidence of asthma in children. Launching the initiative WHO expert Dr Nikolai Khaltaev also emphasised the growing problem in developing countries. ‘India for example has an estimated 15 to 20 million asthmatics’ he said. While factors such as genetic predisposition indoor and outdoor allergens smoking and air pollution are known to be significant risk factors researchers are left struggling to explain J.Environ. Monit. 1999 1 13N Food and tobacco why rates are increasing on average by 50% every decade. WHO rozovi@who.ch www.who.ch Expert group to co-ordinate soil protection A new group to co-ordinate European actions on soil protection was agreed at a meeting in Bonn in December. The European Soil Forum is intended to provide a focus for a policy debate in Europe on a more holistic approach to soil protection. The first meeting of the forum is scheduled for this November following a series of working papers being prepared by the European Commission. These are expected to explore policy options for dealing with contaminated sites and wider soil protection measures. Potential options include a soil framework directive revisions to existing directives on sewage sludge and integrated pollution prevention and control and harmonising soil quality standards.Joint research on soil protection issues is also likely to be discussed. ESF promotes European networking The European Science Foundation has launched eight new programmes aimed at fostering European scientific collaboration. Started in January the programmes cover a variety of fields in the physical life medical and social sciences and will each run for between four and five years. One programme aims to network European research groups studying the genetics ecology pathology and agronomy of genetically modified crops. Another aims to link research traditions in community ecology and ecosystem ecology. A third will study social variations in health expectancy in Europe.ESF asmith@esf.org News Drink and tobacco oYcial carcinogens Alcoholic beverages and environmental tobacco smoke are among six substances being recommended for listing as carcinogens by the US National Toxicology Program (NTP). At its meeting in December a panel of NTP experts reviewed 11 substances or exposure circumstances for potential listing in the NTP’s Ninth Report on Carcinogens due later this year. The other substances accepted for listing as ‘known to be a human carcinogen’ were ethylene oxide nickel compounds crystalline silica and TCDD. Diesel exhaust particulates and isoprene (a constituent in polymers) were recommended as ‘reasonably anticipated to be a human carcinogen’. Ethyl acrylate was delisted and the jury is still out on MTBE and boot and shoe manufacture.Preparation of the carcinogens report is mandated by Congress with the final decision on listings being made by the Department of Health and Human Services. NTP is currently consulting over the move. Comments should be addressed to Dr. C. W. Jameson. jameson@niehs.nih.gov http://ntp-server.niehs.nih.gov/ UK to consult on workplace smoking The UK’s Health and Safety Commission is set to seek public consultation on the introduction of oYcial guidance on passive smoking at work. Responding to the UK government’s White Paper ‘Smoking Kills’ Commission Chairman Frank Davies said oYcial guidance ‘was one possibility for a way forward’ but the Commission ‘has not yet come to a final view’. HSC is due to publish a consultative document shortly including outline guidance and a forecast of any economic impact.The introduction of oYcial guidance in the form of an Approved Code of Practice (ACoP) would represent a major change in the legal framework. Currently employers have no liability for passive smoking under UK law but if they failed to follow an ACoP a court may consider that the employer has broken the law. Health and Safety Commission Tel +44 541 545500 UK backs food irradiation The UK’s Institute of Food Science & Technology has endorsed the use of irradiation as ‘a safe and eVective food processing method’. In a statement issued in December IFST notes that food irradiation appears to be gaining consumer acceptance in the US but has been slow to gain support within many parts of Europe including the UK. The EU remains split on the issue with countries such as Belgium France the Netherlands Portugal and the UK in favour of a directive on food irradiation whereas Denmark Germany and Luxembourg remain opposed.Within the UK seven categories of foods are cleared for irradiation to specified doses and the regulations require that products be clearly labelled. IFST stresses the need for continuing information on the advantages and limitations of the technology so that consumers can make ‘an informed buying decision’. IFST ifst@easynet.co.uk Publications and events CEFIC guides environmental performance Guidelines for chemical companies in reporting health safety and environmental performance have been prepared by the European Chemical Industry Council (CEFIC). At the heart of the system is a set of 16 core parameters which for the first time cover safety and occupational health as well as environmental protection.CEFIC says the new 14N J. Environ. Monit. 1999 1 News framework will make company reporting more consistent and will allow the chemical industry to ‘share the sector’s HSE performance with all stakeholders’. At the moment quantitative data for the sector is only available for two parameters CO2 and energy eYciency but this will be widened to cover all 16 core parameters by 2002. CEFIC www.cefic.be Guidance on use of biological agents Special guidance on the large-scale contained use of biological agents in industry and research has been issued by the UK’s Health and Safety Executive. It is intended to help employers comply with the requirements of the Control of Substances Hazardous to Health Regulations 1994 (COSHH).The guidance covers containment systems and safe working practices where biological agents including GMOs are used in large quantities such as pharmaceuticals food and fine chemicals production academic and research establishments. Areas covered include management systems control measures emergency planning and personal protective equipment. T he large-scale contained use of biological agents ISBN 0-7176-1544-8 price £8.50 COMAH Conference A high profile conference on the new Control of Major Accident Hazards Regulations is being organised by the UK Health and Safety Executive. The Conference takes place on 1–2 March 1999 at the Institute of Civil Engineers 1 St George Street London UK. It is the first of a series of special events to mark the 25th anniversary of the Health and Safety at Work Act.Further details from June Ellis HSE Tel +44 151 951 4595. The Seventh Symposium on the Chemistry and Fate of Modern Pesticides This conference will be held on 14–16 September 1999 at the University of Kansas Lawrence KS USA. Further details from The University of Kansas Division of Continuing Education 1515 St. Andrews Drive Lawrence KS 66047-1625 USA. Tel +1 785 864 4790; Fax +1 785 864 5074; E-mail bproctor@ukans.edu. Policies for people A recent report from an influential UK body urges a more people-focused approach to environmental policies A new approach to deciding environmental policies that takes greater account of people’s values has been called for by the Royal Commission on Environmental Pollution. Launching the report in London the Commission’s Chairman Sir Tom Blundell said ‘For environmental policies to be successful people must have confidence in the way they are being protected against risks.That is best achieved if they are involved at every stage.’ Referring to the scientific controversies of the last few years he stressed there was a need for ‘a much better understanding of the relationship between policies science and values’. Entitled Setting Environmental Standards the report emphasises that protecting the environment has become much more complex. Increasingly the problems are global in scale and may occur some way in the future. Also commitments to sustainable development mean that protection of the environment has to be reconciled with greater material well-being and social justice. Sir John Houghton one of the report’s main authors said that ‘scientific assessments and analyses of technology economics and risks must inform policy decisions but cannot pre-empt them’.He added that ‘setting a standard or target is not only a scientific or technical matter but a practical judgement which has to be made in the light of all the relevant factors’. As well as numerical and legally enforceable limits the report’s definition of ‘environmental standard’ embraces guidelines codes of practice and other criteria used for measuring environmental performance. New forms of environmental standards are evolving for example the green claims made about products environmental reporting by companies and published targets set by governments for environmental quality. Bodies involved in setting standards should ensure their procedures are transparent and open at every stage.They should also leave an ‘audit trail’ recording what factors have been taken into account in their decisions. While direct regulation will continue to be important it will be only one element in a broader portfolio which will include green taxes and charges and voluntary actions by companies and individuals. These alternative approaches based on partnership rather than confrontation make transparency and openness even more crucial. Noting the shift away from national environmental policy-making the Commission says its conclusions apply equally to standards set at European or international level. However while this trend will continue to take eVective account of people’s views the Commission urges that environmental standards should be set at the lowest sensible level. Established in 1970 the RCEP is an independent body that advises the UK government on environmental policy. While the report is based primarily on the UK’s experience it contains much that is of relevance to scientists and policy-makers elsewhere. Setting the Standard T wenty-first Report of the Royal Commission on Environmental Pollution ISBN 0 10 140532 4. Available from the Stationery OYce price £21.40. T he report’s conclusions are available on-line at www.rcep.org.uk Mike Sharpe

ISSN:0960-7919    

DOI:10.1039/em99008n

出版商:RSC    

年代:1999

数据来源: RSC

摘要:

Forum Update on Performance Based Methods System (PBMS) InDecember 1991 theUnited States’ OYce ofManagement and Budget (OMB) issued a statement requiring the review and evaluation of national water quality monitoring activities and the development of recommendations for improvements. Later that year the Intergovernmental Task Force onMonitoringWater Quality (ITFM) was formed to respond to this challenge. ITFM’s charge was to develop a voluntary integrated nationwide monitoring strategy. In May 1997 the NationalWater QualityMonitoring Council (NWQMC) and theMethods and Data Comparability Board (MDCB) were chartered under the Federal Advisory Committee Act (FACA) succeeding ITFM.TheCouncil’s charge is to implement a nationwide strategy to improve water quality monitoring assessment and reporting and oversee the activities of theMDCB.The MDCB is co-chaired by Herb Brass (EPA Cincinnati OH) and Merle Shockey (USGS Arvada CO). Its challenge is to identify examine and recommend monitoring approaches that facilitate collaboration and yield comparable data and assessment results. It is a partnership of water quality experts from Federal agencies States Tribes municipalities industry and private organizations. MDCB will provide the framework and the forum for comparing evaluating and promoting monitoring approaches that can be implemented in all appropriate water quality monitoring programs. ITFM championed the use of PBMS and the MDCB also continues to support PBMS. To this end a Performance Based Methods System Work Group composed of over 20 individuals representing diverse perspectives and chaired by Andy Eaton (Joint Editorial Board Standard Methods and Montgomery Watson Laboratories Pasadena CA) is preparing a position paper on PBMS as one of MDCB’s initial activities.Various distinctions have been made between a performance-based methods system and a performance-based measurement system. The former generally implies the use of reference methods and their associated performance criteria as the standard of comparison to othermethods while the latter requires only stated performance criteria as the comparison standard. It is important to point out that theMDCB endorses the need for reference methods as well as statedperformance criteria which have been shown to be achievable. Thus PBMS as used by MDCB refers to a Performance Based Methods Systemrather than a Performance BasedMeasurement System.It’s important to keep a distinction between these two concepts which unfortunately use the same acronym. Key aspects ofMDCB’s endorsement of PBMSinclude (a) the need to establish measurement quality objectives (MQOs) or data quality objectives (DQOs) for each parameter reported; (b) the need for referencemethods to demonstrate the ability tomeet theseMQOs or DQOs; (c) the need for adequate reference materials to assist labs in demonstrating the appropriateness of a givenmethod (prescriptive or PBMS); and (d) the need for labs to adequately document method performance. PBMS definitions have in common that the concept is a framework that permits the use of any appropriate sampling and analytical technology that demonstrates the ability to meet established performance criteria and complies with specified DQOs and MQOs of the project in which the sampling and analytic technology is employed.To establish and preserve the credibility of performance-based systems performance criteria such as precision bias sensitivity specificity detection level and rates of false positives and false negatives must be designated and a sample collection or sample-analysis method-validation process must be documented. Whether PBMS is called a methods system or a measurement system the basic goals are the same—to provide information of known quality that will satisfy user needs. It is generally agreed by the MDCB that the implementation of a PBMS with corresponding required data qualifiers entered into a multi-user database will allow divergent data from numerous environmental programs to be used for many purposes.Additional information will be available when the work group completes the position paper. In the future you may obtain copies of this position paper from the public Web site of MDCB which is currently under development. Information on progress on the publicWeb site the PBMS position paper and other activities of MDCB is coordinated by Charlie Peters MDCB’s executive secretary. Charlie is best reached by E-mail at capeters@usgs.gov if you desire additional information. Lawrence H. Keith Vice President and Senior Corporate Fellow Waste Policy Institute VA USA Larry_Keith@upi.org J. Environ. Monit. 1999 1 15N NEMI—A National Environmental Methods Index Another priority of the Methods and Data Comparability Board (MDCB— see Update on PBMS above) is the development of a ‘compendium’ of method summaries that can be used to allow rapid communication and comparison of critical parameters of methods for use with method selection modifications and data comparability.A Database/Compendium work group is developing criteria for the information that will be needed for various categories of methods. NEMI will be especially useful for PBMSrelated applications. When ready in pilot form next summer NEMI will contain three categories of methods (sample preparation field methods and laboratory methods) two major types of analytes (1 Chemicals which will have subgroups of typical organic and inorganic analytes nutrients and radionuclides and 2 biologicals which will have subgroups of microbiological and biological ‘analytes’).It will be freely available on the internet and you’ll be able to search it multiple ways in order to meet your specific needs. Searches may be focused with any of the categories or types of analytes using any of the parameters below $ Search by single analyte to find all applicable methods in the database; $ Search for all methods that are applicable to a selected group of analytes using a ‘market basket’ approach to select analytes; $ Search by method to find all the analytes covered by that method; $ Search by keywords using Boolean functions of ‘and’ ‘or’ ‘not’ and ‘near’; $ Search by meta data (selected QC data such as MDL accuracy and precision); $ Search by method source (EPA USGS DOE ASTM AOAC Standard Methods etc.); $ Search by user preference (e.g.AFCEE-approved methods California preferred methods; etc.). Another useful feature is hyperlinks to the full methods when these are available on the Internet. Currently this includes EPA’s SW-846 methods. At some time in the future EPA’s OYce of Water methods also will be on the Internet. Method summaries that you find from your searches of NEMI will be able to be printed or downloaded as files for your personal use. The pilot database being used to develop NEMI is the On-line Environmental Methods Summary Database. This database funded by the Waste Policy Institute currently contains about 1300 analyte/method summaries from 40 EPA methods. It is available for use at http://www.wpi.org/ wpi/prodser. The meta data contained in the method summaries can also be used as input into DQO-PRO (free software linked from this same site) in order to calculate estimated confidence levels for your analytical data based on numbers of samples analyzed.Future enhancements may include simple front-end interfaces to NEMI that will help people use the Data Quality Objective (DQO) Process to design goal-oriented monitoring programs. By querying users for their requirements of analytes and selected meta data their replies could serve as automatic search criteria for NEMI and facilitate PBMS method selections. Information on NEMI and other activities of MDCB is coordinated by Charlie Peters MDCB’s executive secretary. Charlie is best reached by E-mail at capeters@usgs.gov if you require additional information. Lawrence H. Keith Vice President and Senior Corporate Fellow Waste Policy Institute VA USA Larry_Keith@upi.org 16N J.Environ. Monit. 1999 1 Thematic Programmes Quality of life and User-friendly Competitive and Preserving the living resources information society sustainable growth ecosystem Programme 1 Programme 2 Programme 3 Programme 4 Key Actions+Generic Technologies+Research Infrastructure Horizontal Programmes International Role of Innovation and Human Potential & Community Research Participation of SMEs Socio-Economic Research Coordination and Specific Actions Forum Towards the Fifth EC-Framework Programme The European Commission will soon launch the Fifth Framework Programme for Research and Development (1998–2002) (FP5) which has been conceived as a break with the past in comparison with the Fourth Framework Programme (1994–1998).The new general policy guidelines which put research at the service of the people will be best achieved by improving the bases of European competitiveness within a perspective of sustainable development. The Fifth Framework Programme is merely designed to support and enhance scientific and technological excellence while being relevant to main EU policies and of European added value. The objectives are defined according to socioeconomic and competitive needs placing more emphasis on the results and focusing on a limited number of topics. A simplified structure is proposed consisting of four Thematic Programmes and three Horizontal Programmes. Thematic programmes The four Thematic Programmes are aiming respectively to (1) improve the quality of life and management of living resources (2) create a userfriendly information society (3) promote competitive and sustainable growth and (4) preserve the ecosystem.Each Thematic Programme is organised in the form of Key Actions Generic Technologies and Research Infrastructures (see below) Each Key Action will be problemoriented and targeted to the objectives of the respective Programme. The aim is to link them to major and social objectives with relevant national and international initiatives and to integrate activities and disciplines (from basic research to development and demonstration) in close consultation with the scientific community industry and users. Generic Technologies will aim to develop the European technological capacity and to stimulate flow of ideas and knowledge to complement the Key Actions. They will focus on a limited number of areas not covered by the Key Actions and on potential multisectoral applications.The Research Infrastructure will promote an optimal use and wide access to existing research infrastructures and develop transnational cooperation in a rational and cost eVective context. This Community added value will be complementary to national and multinational initiatives (e.g. networking). Horizontal programmes These programmes will deal with (1) International Role of Community Research (2) Innovation and Participation of SMEs and (3) Human Potential and Socio-Economic Research. These activities will be based on coordination support and accompanying measures of Thematic Programmes and support to other Community policies. Complete information on the diVerent programmes can be obtained through the Internet ( http://www.cordis.lu/).Implementation Improved management practices will be developed ensuring a co-ordination between diVerent programmes research programmes and other EU activities (e.g. technical and economic assistance education and training structural funds and other EU policies) and European and national activities while keeping a flexibility by regularly adapting the work programmes. Indicative timetable The first reading by the European Parliament took place on 18 December 1997. A common position was adopted by the Council on 23 March 1998. The Fifth Framework Programme has been oYcially adopted by the Council and European Paliament of the EU on the 22nd December 1998. The overall budget is 14,960 million Euros. Research in support of environmental monitoring Projects dealing with environmental monitoring will find their way in various places.The Thematic Programmes 1 and 4 (see above) will cover topics related to environmental studies development of new methods and instrumentation for environmental monitoring and research in support of standardisation for environment-related analyses. Programme 1 will focus on living resources whereas Programme 4 will cover all types of environmental research projects. The Thematic Programme 3 will include Generic Technologies on Measurements and Testing which will pursue the activities of the present Standards Measurements and Testing Programme. With respect to environmental matters however only projects related to research on new Certified Reference Materials will be consided in these Generic Technologies; the Research Infrastructure of Programme 3 (see above) will cover projects aiming to produce new CRMs (as a result of feasibility studies undertaken in the Generic Technologies) and to organise interlaboratory studies.It should be stressed that all projects will need to be linked either to EU policies or have an industrial impact. Horizontal Programmes will also include research areas related to environmental monitoring e.g. projects developed in partnership between EU and non-EU organisations (International Role of Community Research) projects involving SMEs (Innovation and Participation of SMEs) and projects with a socio-economic impact and stimulating the mobility and training of researchers (Human Potential & Socio-Economic Research).Potential proposers willing to submit research projects within the FP5 are strongly encouraged to carefully read the work programmes of the diVerent specific programmes as soon as they are available. In many instances projects are considered to be out-ofscope simply because the problem does not focus on the respective specific programmes. A good practice is to read the relevant programme in detail and to seek advice (if necessary) on specific projects by contacting the responsible EC helpdesk prior to the submission of the proposal. Updated information on the calls for proposals expected to be published in 1999 on environmentrelated topics will be given in the second issue of JEM. Additional information on FP5 can be obtained through Michel Claessens Communication Unit Fax +32 22958220; E-mail michel.claessens@dg12.cec.be Ph.Quevauviller Brussels Belgium J. Environ. Monit. 1999 1 17N † This article is based on R. H. Brown ‘New European legislation and its relation to methods performance criteria and standardisation’ ACGIH 1998 Applied Workshop Chapel Hill NC February 1998. Forum CEN Air Quality Standards† Two new European Directives on Air Quality have been promulgated recently namely a Chemical Agents Directive (98/24/EC)1 and an Ambient Air Directive (96/62/EC).2 The first concerns the workplace and the second outdoor air but both require an assessment of air quality and both imply a requirement for actual measurement. If measurement results are to be comparable across Europe there is also a requirement for standardisation of such measurements either as defined reference methods or as method performance requirements.The Technical Committee TC137. This Committee took the view that air quality assessment standards should take the form of performance requirements rather than prescribed methods. This approach has the advantage of allowing any method to be used which meets these requirements without stifling innovation and development. The actual writing of standard measurement procedures was taken to be the role of ISO or member state regulatory bodies such as HSE the Health and Safety Executive (for example the MDHS series). The approach taken by WG2 has been to develop a hierarchy of standards with a general performance requirements document at the top and a series of specialised standards under this umbrella. task of standardisation in the field of measurement is ultimately the responsibility of the European Commission but it usually devolves this responsibility to Scientific Expert Groups reporting to the Commission or to Technical Committees of CEN the Comite� Europe�en de Normalisation.The development of standard measurement procedures ideally meeting the Cerformance criteria is also the responsibility of ISO the International Organisation for Standardisation. Workplace Standards The task of developing appropriate standards for workplace air quality measurements within the European Community has been carried forward by working groups (WGs) of CEN 18N J. Environ. Monit. 1999 1 Forum Umbrella Standard The umbrella standard3 provides among other things definitions and minimum requirements for unambiguity (the uniqueness of the result) selectivity (which depends on whether detailed knowledge of the air composition is known in advance) and overall uncertainty (a combination of precision and bias).Second Tier Standards These standards contain specific (minimum) performance requirements for measuring devices together with the appropriate test methods. So far the standards for diVusive samplers,4 pumped sorbent tubes,5 detector tubes6 and low volume sampling pumps7 have been published. Standards are being prepared for high volume pumps sampling and analysis of metal species (or more generally of chemical agents in airborne particles) samplers for mixed aerosols and vapours and jointly with a CENELEC working group for direct-reading electrical apparatus. Guidance is also being prepared for chemically impregnated systems and for the selection of procedures and devices.Ambient Air Standards The task of developing appropriate standards for ambient air quality measurements within the European Community has been carried forward by working groups (WGs) of CEN Technical Committee TC264. In addition to the ‘framework’ Directive on Ambient Air Quality Assessment and Management,2 several associated Daughter Directives have been promulgated or are under development. These Directives prescribe performance requirements as Data Quality Objectives (DQOs) including accuracy and precision minimum data capture and minimum time coverage. DQOs are set at diVerent levels for diVerent pollutants and also for diVerent assessment methods; mandatory measurment indicative measurement modelling or objective estimation.Usually a ‘reference’ method is prescribed but other methods meeting the DQOs may be used. The primary task of CEN TC264 is to evaluate and recommend reference methods where these are not already prescribed in Directives. However in the specific case of diVusive samplers which are likely to be used for indicative measurement performance requirements standards have been developed by CEN/TC 164/WG 11 analogous to EN 4823 and EN 8384 of CEN/TC137/WG 2. References 1 Council Directive 98/24/EC on the protection of the health and safety of workers from the risks related to chemical agents at work 1998. 2 Council Directive 96/62/EC on ambient air quality assessment and management 1996. 3 Workplace atmospheres—General requirements for the performance of procedures for the measurement of chemical agents (EN 482 1994).4 Workplace atmospheres—Requirements and test methods for diVusive samplers for the determination of gases and vapours (EN 838 1995). 5 Workplace atmospheres—Requirements and test methods for pumped sorbent tubes for the determination of gases and vapours (EN 1076 1997). 6 Workplace atmospheres—Requirements and test methods for short term detector tube systems (EN 1231 1996). 7 Workplace atmospheres—Requirements and test methods for pumps for personal sampling of chemical agents (EN 1232 1997). Richard Brown Health and Safety Executive UK Progress with the ambient air directive and its implications On the basis of the experience gained from earlier air quality directives the European Union adopted in 1996 a new Directive on Ambient Air Assessment and Management which established a more integrated and coherent approach to air quality.This directive constitutes the framework for the development of specific Daughter Directives for a series of pollutants. The first Daughter Directive for SO2 NO2 PM10 and Pb has recently been submitted by the European Commission to the Council of Ministers and the European Parliament and is expected to be adopted in 1999. Further Daughter Directive proposals for Benzene and CO as well as the revised O3 directive are currently being finalized by the Commission and will be presented to the Council and the Parliament at the beginning of 1999. The preparation of the Daughter Directive proposal for Heavy Metals (Cd As Ni Hg) and for PAHs will start in 1999 and is foreseen to be submitted to the Council and the Parliament at the end of the year.For each pollutant the daughter directives will establish air quality standards for the protection of human health and vegetation criteria for the location and the minimum number of mandatory measurement sites reference measurement techniques and related data quality objectives criteria for the use of indicative assessment methods. As a general trend in the management of air quality the new regulation will require integrated approaches based on intelligent assessment. Besides the mandatory monitoring activity needed to control the compliance of limit values other tasks have become an absolute priority such as the proper design and optimization of the monitoring networks the classification of a territory in zones of homogeneous air quality the use of alternative assessment techniques to produce maps of the air quality in a given area the use of modelling tools to simulate and forecast air quality levels the information provided to the public the implementation of eYcient abatement measures.The forthcoming benzene directive oVers researchers working with thermal desorption methods new and interesting opportunities active sampling on a sorbent cartridge is proposed as one of the reference measurement methods. In addition the diVusive sampling technique constitutes a powerful tool for the classification of zones preliminary assessments of ambient air quality the design/optimization of monitoring networks monitoring in areas at no risk of exceeding limit values classification in zones of homogeneous air quality validation and mathematical models and measurement campaigns to evaluate the eYciency of abatement measures. Emile De Saeger JRC Environment Institute Italy

ISSN:0960-7919    

DOI:10.1039/em99015n

出版商:RSC    

年代:1999

数据来源: RSC

摘要:

J. Environ. Monit. 1999 1 19N † I use the word ‘uncertainty’ (u) to indicate standard uncertainty as defined in the ISO Guide to the Expression of Uncertainty of Measurement and ‘reliability’ to indicate an extended uncertainty the range in which we expect the true value to lie. Viewpoint Sampling the uncertainty that dares not speak its name ‘How reliable are these analytical results?’ This is a question that the end user of analytical data—presumably the person who is paying for it—always should and increasingly does ask. Decisions based on analysis depend not only on the actual result but on its associated reliability. Most analytical chemists respond to the ‘reliability question’ by citing precision estimates that they make during the validation of the method. A proportion of these will know that a major part of the measurement uncertainty arises because of diVerences between laboratories and give you the reproducibility precision which incorporates this extra source of variation.Perhaps some will be able to say that their estimate of reliability includes terms that allow for any bias that might be present in the analytical method. Yet even the best of these answers fails to address what the enduser is really asking. Why does this failure occur? Simply because the end-user is usually seeking information about the composition of a ‘target’ a large body of material say the soil in a field or the atmosphere in a building. In contrast the analyst’s result with its associated uncertainty uan refers to the sample the usually much smaller amount of material that is subjected to the analytical procedure.† These two things are not identical.Almost everything that is worth analysing is actually or potentially heterogeneous. Consequently any sample is likely to have a composition that is diVerent from the mean composition of the target and no two samples will have the same composition. This variation in composition even among properly collected samples is quantified as the sampling uncertainty usam. The failure accurately to inform the end-user arises because we do not normally take the sampling variations into account when we are assembling an uncertainty budget. As the squares of the uncertainties are cumulative that is utotal2=usam2+uan2 potentially serious misunderstandings could occur if the sampling uncertainty were larger than the analytical uncertainty.Nowhere is this problem likely to be greater than when we sample environmental materials contamination after all is often very uneven in both space and time so sampling precisions are correspondingly high. So how do we address this sampling uncertainty? In fact little has been done so far on the subject so we have no well established guidelines. A practical approach would be to list all of the concepts and practices relating to quality in analysis and see if they can be sensibly applied to quality in sampling. So we need to consider the following topics as potentially useful in sampling error accuracy bias trueness precision uncertainty reference materials proficiency tests collaborative trials and internal quality control. Things are simpler than this agenda suggests at first sight however.Accuracy is no more than lack of error which itself is simply the sum of the random error (characterised by precision) and any systematic error engendered by bias. Trueness is lack of bias. Uncertainty (or lack of reliability) is a measure that encompasses all types of error. Reference materials address bias collaborative trials and internal quality control mainly address aspects of precision while proficiency tests look at the accuracy of single results. It seems that we need consider only precision and bias as the fundamental concepts that might apply to sampling all the rest should follow. Basic concepts Precision in principle is easy to estimate because experimentally it requires only the ‘Two Rs’ randomness and repetition. So for sampling precision we would need to replicate the taking of samples according to a definite protocol but randomise the method in some way for each sample.For instance if the protocol required that 10 increments were collected and combined to make the aggregate sample the positions of those increments (in space or time) would have to be randomised for each sample. In practice however this might be very diYcult or costly to execute. Furthermore we cannot know exactly the true compositions of the aggregate samples we have to estimate them by analysis which adds an extra layer of error to the final result. Hence we need to use a designed experiment and employ analysis of variance to apportion the precision between sampling and analysis. Sampling bias is a more diYcult issue. Some experts on sampling even deny the validity of the concept.The basis for such a view is that if sampling is carried out correctly (that is according to the accepted protocol) it cannot be biased. (This is equivalent to regarding an analytical method as ‘empirical’ or ‘definitive’.) However it is easy to see that bias could be introduced into sampling in a number of ways for instance by systematically using an incorrect procedure or by contaminating the material with the sampling tools. And what can happen sooner or later does! Bias in analysis is sought (among other methods) by comparing the results of the candidate analytical method with the results obtained by using an independent reference method. This strategy in sampling using a reference sampling method for comparison at least seems feasible. The diYculties of the alternative setting up and using the sampling analogue of a reference material seem to be insurmountable.A useful design for studying sampling bias would be to apply both methods of to a number of diVerent targets so as to encompass within the study the typical ranges of both the concentration of the analyte and any variations in the nature of the defined target material. The paired samples could then be analysed together (so that any analytical bias cancels out) and any sampling bias appraised by a suitable statistical method. This simple idea apparently has not been exploited as yet. At the moment it seems we need to find out 20N J. Environ. Monit. 1999 1 Viewpoint Certainly the idea of replication (essential to estimate precision) and randomness (essential to avoid bias) seem at first sight to be undermined here.So can the ideas previously established for static sampling be adapted here for these commonplace situations? I believe that they can. First monitoring is no more than sampling for contiguous short time intervals. We can never really get a continuous signal any recording device will smear the signal out over a certain time interval. So there is no precision problem unique to monitoring it is simply an extreme example of sampling in time. (Normally of course we assume that the system is suYciently stable to obviate any time eVect.) So we can obtain random replicate samples in time simply by restricting our activities to a time-frame appropriate for the sampling target under consideration. Second consider the need to sample in a specific place rather than at random.Duplication could be achieved by having two parallel monitors adjacent to each other for example passive monitors on both sides of a worker’s overall collar. It seems that there is no insuperable scientific problem about extending the ideas of data quality to environmental sampling although economic and political diYculties might become apparent if we tried to carry it out. To exercise quality assurance on sampling would undoubtedly require expenditure in the first instance just as it did when it was introduced for analysis. But in the longer run the knowledge provided could bring about an overall saving by helping us make the best possible use of the available resources. We could employ an optimal apportionment of cash between the cost of sampling and the cost of analysis if we knew about their uncertainties.For instance we might find that we could obtain more information at lower cost by collecting twice as many samples and then subjecting them to a relatively crude analytical method. The political problems would arise when end-users found out just how poor sampling reliability is in some instances. They might even conclude that the whole process was not worth doing if the result is so unreliable. Fitness for purpose This article began with a question about the reliability of an analytical a particular sampler. Internal quality control in sampling seems to be considerably more promising method as we can restrict our interest to precision. Moreover there is only a small financial penalty involved in executing it. It seems that we need worry only about sampling precision under repeatability conditions.(Reproducibility precision is impossible to monitor as a matter of routine and between-run precision would be diYcult because the sampling target would tend to disappear before we could get back to it for a second try!) Therefore some simple and inexpensive strategies should suYce for an IQC procedure. Suppose for example that the sampling protocol called for the aggregation of n increments selected at random. The within-run sampling precision could be monitored by aggregating two subsets each comprising n/2 increments selected at random and analysing the two subaggregates separately. The mean of these two results would be the reported analytical result and the diVerence between the results would have a precision (standard deviation) of s=2Óssam2+san2/2.This s could be used to set up limits for a control chart with zero mean which would reflect variation in sampling and analysis jointly. However unless san>0.7ssam (which is unlikely in environmental analysis) analytical variation would make a negligible contribution to s so the chart could be regarded for practical purposes as monitoring within-run sampling precision alone. Moving targets Up to this point I have treated sampling as if sampling targets were static as if we could return to them a number of times and find them pretty well unchanged. However many environmental materials are rapidly changing in both time and space. We may be interested in the composition of something that is potentially always changing such as the composition of a river subject to sporadic contamination ‘You cannot sample the same river twice’ according to Heraclitus the famous Greek analyst from the fifth century BCE.Alternatively the sampling target may be moving in space for instance the atmosphere in the vicinity of a worker who is moving about. This broader perspective for sampling raises the diVerence (if any) between sampling and monitoring. more about bias before trying to incorporate it into sampling uncertainty. Practical methods? Having examined the basic ideas we can now consider the practical measures that might be taken in relation to sampling. The ‘Full Monty’ method for estimating sampling precisions for a particular sampling protocol would be the equivalent of a collaborative trial (method performance study).We must envisage a number of samplers visiting the target independently and collecting duplicate samples at random. After analysis of all the samples (under randomised repeatability conditions) we could estimate the sampling precisions of repeatability (within-sampler) and reproducibility (between-sampler) using a nested analysis of variance. A few such trials have been carried out in experiments involving several diVerent type of material (soils sediments crops) and for some of these have demonstrated a distinct betweensampler eVect. Collaborative trials are certainly expensive but throw interesting light on the quality of sampling in specific methods. Proficiency testing in analysis is organised by distributing samples of a homogeneous material to the participants who independently analyse the material and report the result(s) back to the organiser.The organiser then assesses the results and reports the outcome back to the participants. This provides an opportunity for the participants to address the cause of any unsuspected discrepancies in their results. Proficiency testing in sampling is at least conceivable so long as all of the participants could visit the sampling target within its period of stability. That would often be impracticable for example in the analysis of workplace atmospheres. Moreover it is clearly not feasible to send environmental-type targets to the samplers! So again a considerable use of resources would be required. Sampling proficiency tests have been carried out on an experimental basis and are certainly practicable but it is not clear whether they will prove to be cost-eVective for general use.However our experience in analysis shows that the proficiency test analogue is the only device that is capable of demonstrating an unsuspected problem in sampling by J. Environ. Monit. 1999 1 21N Viewpoint result and concludes with a diVerent but related question namely ‘How reliable do these results need to be?’ The simple answer is that the uncertainty of the result should be suYciently small so that decisions based on the result should be correct with a given high probability but no smaller than that because reliability costs money. In quantitative terms we should seek to employ sampling and analytical methods with uncertainties of a magnitude that minimises the statistical expectation of all financial losses related to the uncertainty.(Obviously sampling and analysis cost money and the smaller the uncertainty the greater the costs. There are also costs associated with providing the end user with inaccurate data and these cost will rise with the uncertainty.) This minimisation is easy to do in principle but may require help from other professionals in practice because it is diYcult to quantify both the probability and the cost of certain remote possibilities. At present for the sampling of almost anything there is a protocol regarded as best practice in that field. In contrast there is an almost total lack of quantitative information about how well these protocols perform. We have seen that most of the problems of assessing sampling uncertainty can in principle be addressed by methods similar to those used for analytical uncertainty. In practice there are often considerable diYculties because of the sheer size (and often the financial value) of the sampling target. Moreover there is an understandable lack of enthusiasm for rousing the sleeping dogs of sampling when there is a fair chance of being severely bitten. Nevertheless unless analytical chemists can address these problems we cannot give the customers what they really want. Michael Thompson Birkbeck College London UK

ISSN:0960-7919    

DOI:10.1039/em99019n

出版商:RSC    

年代:1999

数据来源: RSC

摘要:

Development of an international standard for the determination of metals and metalloids in workplace air using ICP-AES: evaluation of sample dissolution procedures through an interlaboratory trial† Owen T. Butler and Alan M. Howe Inorganic Exposure Assessment Section, Health and Safety Laboratory, Broad Lane, SheYeld, UK S37HQ Received 28th September 1998, Accepted 3rd December 1998 Inductively coupled plasma atomic emission spectrometry (ICP-AES) is rapidly overtaking atomic absorption spectrometry (AAS) as the method of choice for the determination of toxic metals in workplace air.However, the few ICP-AES methods that have been published are not well characterised in terms of the eVectiveness of the sample dissolution procedures described and their validation status. The International Standards Organization (ISO) is currently engaged in developing ISO 15202, which will describe a generic method for the determination of metals and metalloids in airborne particulate matter by ICP-AES.One part of the proposed standard deals with dissolution procedures. The ISO work has been supported by a project carried out in the authors’ laboratory to identify, develop and validate sample dissolution procedures for inclusion in the proposed standard.This paper describes an interlaboratory comparison carried out to assess the performance of selected procedures using samples of airborne particulate matter collected on filters with a multiport sampler. Five dissolution procedures were tested. These included an ultrasonic agitation procedure, two hot-plate procedures (based upon NIOSH 7300 and OSHA ID 125G) and two microwave-assisted procedures (based upon EPA 3052).It was shown that the dissolution procedures selected for use in the trial and used internally at HSL generally gave equivalent performance. As expected, a wider spread of results was obtained by participants in the trial. More specifically, there exists some reservation regarding the ability of the ultrasonic and hot-plate procedures to attack fully on a consistent basis some resistant materials, e.g., chromium containing particulate matter.Above all, the trial demonstrated the usefulness of microwave-assisted dissolution procedures in a modern laboratory. comparison carried out to assess the performance of selected Introduction procedures using samples of airborne particulate matter col- The health of workers in many industries is at risk through lected on filters with a multiport sampler.exposure by inhalation to toxic metals and metalloids. Occupational hygienists need to determine the eVectiveness of Experimental measures taken to control workers’ exposure, and this is generally achieved by making personal exposure measure- Procedures tested in the interlaboratory comparison were ments, the accuracy of which relies heavily upon the availability selected on the basis of preliminary work carried out at the and use of validated measurement methods.Health and Safety Laboratory (HSL). A number of potentially Inductively coupled plasma atomic emission spectrometry suitable dissolution procedures were first identified in a litera- (ICP-AES) is rapidly overtaking atomic absorption spectrometry ture search.1 From this list, procedures to be included in the (AAS) as the method of choice for the determination of toxic proposed standard were selected, based not only on their likely metals in workplace air.However, the few ICP-AES methods performance, but also on the need for them to gain acceptance that have been published are not well characterised in terms of from the international community.Procedures already advothe eVectiveness of the sample dissolution procedures described cated by regulatory bodies were therefore favoured. and their validation status. The International Standards An in-house assessment of the selected dissolution pro- Organization (ISO) is currently engaged in developing ISO15202, cedures was then carried out using certified bulk reference which will describe a generic method for the determination of materials and other well characterised bulk materials taken metals and metalloids in airborne particulate matter by ICP- from the working environment.2–4 The results obtained showed AES.The existence of an International Standard will be of benefit that the selected procedures, although not universally applito agencies concerned with health and safety at work, industrial cable, were eVective for a wide range of elements in a wide hygienists, analytical laboratories and industrial users of metals range of materials. and metalloids and their workers. It was therefore decided to proceed with an interlaboratory One part of the proposed standard deals with dissolution comparison to obtain qualitative information on the rugprocedures.The ISO work has been supported by a project gedness of the procedures selected for inclusion in the proposed carried out in the authors’ laboratory to identify, develop and standard. validate sample dissolution procedures for inclusion in the Procedures evaluated proposed standard.This paper describes an interlaboratory Nitric acid–hydrofluoric acid procedure using ultrasonic agitation. Sample dissolution procedures using ultrasonic †©Crown copyright. J. Environ. Monit., 1999, 1, 23–32 23Table 1 Participant details bath and ultrasound for 1 h. Dilute to 25 ml with water in a calibrated flask.Technique used Hot-plate procedure using nitric acid–perchloric acid. Hot- Country ICP-AES AA ICP-MS Total plate procedures using a mixture of nitric and perchloric acid Australia 2 — — 2 have been recommended over many years for the dissolution Belgium — 1 — 1 of air filter samples, e.g., in National Institute for Occupational Canada 1 — — 1 Safety and Health (NIOSH) Method 7300, for elements in Denmark 1 — — 1 airborne particulate matter using ICP-AES8 and in British Germany 2 1 — 3 Standard BS 6691,9 for fume from welding of alloyed steel.Finland — 1 — 1 France 4 2 — 6 The procedure is also commonly used at the HSL for the Italy 1 — — 1 dissolution of air filter samples. A brief summary of the New Zealand — — 1 1 procedure is as follows: Norway 1 — — 1 Spain — 3 — 3 Place the filter sample in a 50 ml beaker and add 5 ml of nitric UK 12 4 1 17 acid and 1 ml of perchloric acid.Place on a hot-plate and heat USA 9 — — 9 until dense white fumes of perchloric acid are evolved. Remove Total 33 12 2 47 from hot-plate and allow to cool (if chromium is required, 1 ml of hydrogen peroxide is used to reduce chromium to the trivalent state).Add 5 ml of hydrochloric acid and heat the sample until near boiling. Allow to cool and dilute to 25 ml agitation are currently much in vogue, as can be seen in the with water in a calibrated flask. open literature, e.g., the determination of lead in environmental matrices5 and the analysis of ambient airborne particulate Hot-plate procedure using hydrogen peroxide–sulfuric acid.matter.6 In addition, procedures using ultrasonic agitation are A hot-plate procedure using a mixture of hydrogen peroxide advocated by INRS (France) and the EPA (USA) for the and sulfuric acid is used in a generic procedure developed by analysis of airborne particulate matter. It was therefore decided the Occupational Safety and Health Administration.10 This to investigate the performance of an ultrasonic procedure procedure, ID-125G, describes the use of ICP-AES for the using a mixture of nitric and hydrofluoric acid.This was analysis of airborne particulate matter. A brief summary of similar to a procedure used by INRS and the French Social the procedure is as follows: Security regional laboratories (CRAMs) for the analysis of air samples collected on glass or quartz fibre filters.7 A brief Place the filter sample in a 50 ml beaker and add 2 ml of summary of the procedure is as follows: sulfuric acid (1+1), followed by a few drops of hydrogen peroxide.Place on a hot-plate and heat until dense white Place the filter sample in a disposable graduated 30 or 50 ml centrifuge tube, add 3 ml of hydrofluoric acid and 2 ml of fumes of sulfuric trioxide are evolved.Remove from the hotplate and allow to cool. Add 5 ml of hydrochloric acid and nitric acid and cap. Place in a pre-heated (60±2 °C) ultrasonic Table 2 Digestion procedures tested Procedure Acid mixture Procedure based upon No. of data sets returned Ultrasonic HNO3–HF INRS/CRAM method 8+1a Hot-plate HNO3–HClO4–HCl NIOSH 7300 11+1a Hot-plate HNO3–H2SO4–HCl OSHA 125G 14+1a Microwave-assisted HNO3 EPA 3052 9+1a Microwave-assisted HNO3HF (+HCl) EPA 3052 6+1a Microwave-assisted HNO3–HClO4–HF (+HCl) EPA 3052 1a Total 48+6a aData returned by HSL.Table 3 Filter sample details Elements present for purpose of trial Filter type Fume/dust source Sample ID Ag Cd Co Cr Cu Fe Mn Mo Ni Sn W Zn Welding fume Corofil 309L flux core arc F1/A/XXX m m m m welding F1/B/XXX Welding fume Nimrod 182 manual metal arc F2/A/XXX m m m m welding F2/B/XXX Welding fume Cobstel 6 flux core arc F3/A/XXX m m m m welding F3/B/XXX Welding fume Nimrod C276 flux core arc F4/A/XXX m m m m m welding F4/B/XXX Silver solder TIG welding using Sif silver F5/A/XXX m m m m fume solder No. 42 F5/B/XXX Ore dust IGS 26 dust, sieved, F6/A/XXX m m m m m wet-milled and dried.Dust F6/B/XXX generated using Wright dust feeder 24 J. Environ. Monit., 1999, 1, 23–32Table 4 Data obtained at HSL (mg per filter) Dissolution with HNO3–HClO4–HF in a Ultrasonic agitation microwave oven: nominal data Filter Element with HNO3–HF: procedural data mean±s (n=4) Filter F1/A/XXX Cr 25.5, 24.9 38.2±1.4 Fe 53.9, 52.7 56.9±2.0 Mn 53.4, 52.6 58.3±2.0 Ni 7.1, 6.8 8.1±0.1 Filter F1/B/XXX Cr 59.8, 58.9 74.1±2.6 Fe 96.4, 97.8 99.0±2.4 Mn 99.8, 101 107±3 Ni 13.3, 13.5 15.0±0.7 Filter F2/A/XXX Cr 8.1, 8.0 8.8±0.4 Fe 9.4, 8.9 8.7±0.5 Mn 20.7, 20.3 21.6±0.5 Ni 12.2, 12.4 13.0±0.3 Filter F2/B/XXX Cr 21.6, 22.4 22.9±1.0 Fe 6.6, 6.6 5.5±0.7 Mn 58.3, 58.1 57.3±0.9 Ni 32.2, 32.6 32.4±0.4 Filter F3/A/XXX Co 104, 104 115±1 Cr 39.6, 39.1 55.6±0.9 Fe 25.7, 25.8 25.8±0.9 Mn 15.8, 15.8 18.1±0.6 Filter F3/A/XXX Co 224, 224 243±3 Cr 132, 133 153±3 Fe 40.2, 37.3 40.8±1.3 Mn 38.0, 38.1 41.4±0.5 Filter F4/A/XXX Cr 31.5, 33.1 45.7±1.0 Fe 13.9, 14.7 15.5±0.5 Mn 13.0, 12.3 15.1±11.1 Mo — 8.3±0.2 Ni 26.2, 27.5 32.8±0.2 Filter F4/B/XXX Cr 84.4, 83.1 101±3 Fe 27.1, 27.8 28.3±1.2 Mn 33.6, 33.4 37.4±1.6 Mo — 20.3±0.3 Ni 50.0, 50.0 57.8±1.1 Filter F5/A/XXX Cd 991, 989 992±16 Cu 15.9, 15.5 14.9±0.1 Zn 453, 451 459±6 Filter F5/B/XXX Cd 405 407±4 Cu 9.7 9.5±0.4 Zn 185 189 ±2 Filter F6/A/XXX Cu 32.7, 34.2 33.4±0.6 Fe 164, 171 179±2 Mn 16.1, 16.7 17.7±0.4 W — 165±5 Filter F6/A/XXX Cu 13.5, 13.5 12.9±0.8 Fe 66.3, 66.8 68.2±0.8 Mn 6.8, 5.0 6.9±0.8 W — 59.8±1.7 heat the sample until near boiling.Allow to cool and dilute standard.Therefore, for the purpose of this interlaboratory comparison, procedures using nitric acid and a combination to 25 ml with water in a calibrated flask. of nitric and hydrofluoric acid were tested. A brief summary of the procedure is as follows: Microwave-assisted closed vessel procedure. With the increasing sophistication of analytical instrumentation, sample prep- Place the filter sample in a digestion vessel, add 5 ml of nitric aration has become the limiting step in the overall analysis acid or 4 ml of nitric acid and 1 ml of hydrofluoric acid and scheme.The use of microwave-assisted digestions is an attractcap. Place in the microwave oven and set a programme to ive proposition, since sample dissolution times can be shortoperate the following temperature profile: to reach 180±5 °C ened considerably.In addition, laboratory microwave ovens in less than 10 min and to hold at 180±5 °C for 15 min. Allow are mostly microprocessor-controlled, allowing automated to cool and, if necessary, add 5 ml of hydrochloric acid and operation. Microwave digestion techniques are becoming repeat the digestion programme.Transfer and dilute to 25 ml increasingly popular in analytical laboratories. In the occuwith water in a calibrated flask. pational hygiene field, a number of procedures suitable for the analysis of airborne particulate matter have been published, e.g., in Health and Safety Executive (HSE) methods MDHS Other dissolution procedures. It is proposed that ISO 15202 will contain a number of other dissolution procedures, includ- 12 and 4211 and papers by Paudyn and Smith12 and Bettinelli et al.13 Along similar lines, Method 3052 developed by the ing a leach procedure for water soluble metals and metalloids, a nitric–hydrochloric acid hot-plate procedure and a micro- Environmental Protection Agency14 is a total digestion procedure for various environmental matrices.It is planned to wave procedure involving the use of perchloric acid. Additionally, plans are in hand to investigate and, it is hoped, incorporate a procedure based upon EPA 3052 in the proposed J. Environ. Monit., 1999, 1, 23–32 25Table 5 Data obtained at HSL (mg per filter) Dissolution with Dissolution with Dissolution with Dissolution with Dissolution with HNO3–HClO4–HCl H2O2–H2SO4–HCl HNO3 HNO3–HF HNO3–HClO4–HF Filter Element on a hot-platea on a hot-platea in a microwave ovena in a microwave ovena in a microwave ovenb F1/A/XXX Cr 37.6 32.4 37.5 37.7 38.1±1.1 Fe 58.8 55.9 58.9 59.5 58.9±2.2 Mn 57.6 56.5 57.8 58.0 57.6±1.4 Ni 8.0 7.1 7.7 7.5 8.2±0.2 F1/B/XXX Cr 74.0 63.5 74.2 74.8 75.2±1.7 Fe 101 96.9 102 101 102±2 Mn 107 100 109 108 108±0.2 Ni 15.1 14.1 14.8 14.0 15.1±0.2 F2/A/XXX Cr — — 8.7 8.9 9.2±0.4 Fe — — 10.5 11.7 10.8±0.7 Mn — — 21.6 20.7 21.5±0.5 Ni — — 12.5 12.1 12.8±0.3 F2/B/XXX Cr 24.5 20.9 22.1 22.9 23.2±0.8 Fe 9.1 8.6 6.5 6.8 6.8±0.5 Mn 60.6 56.9 57.8 58.4 58.4±2.2 Ni 32.8 31.2 32.2 30.9 32.5±0.3 F3/A/XXX Co 109 110 115 114 116±2 Cr 50.4 46.8 52.9 51.1 55.2±1.2 Fe 27.6 26.8 27.5 27.5 26.9±1.0 Mn 17.4 17.2 17.8 17.9 17.9±0.6 F3/B/XXX Co 226 237 236 242 241±6 Cr 138 142 145 147 153±4 Fe 40.4 39.9 39.4 40.5 40.4±1.2 Mn 38.9 40.1 39.3 40.2 41.2±0.5 F4/A/XXX Cr 42.0 36.5 44.4 44.6 46.0±0.9 Fe 15.7 15.5 16.9 17.0 17.0±0.3 Mn 12.7 12.8 14.1 14.0 15.0±0.5 Ni 32.6 28.2 31.9 33.3 33.3±0.9 F4/B/XXX Cr 95.7 92.4 99.6 102 102±2 Fe 29.8 31.8 30.3 29.7 29.1±0.3 Mn 35.9 36.1 37.2 37.5 37.6±0.6 Ni 58.0 56.5 58.0 56.9 58.8±1.0 F4/A/XXX Mo — — — — 7.3±0.2 F4/B/XXX Mo — — — — 18.6±0.6 F5A/XXX Cd 991 985 984 971 969±19 Cu 14.4 14.5 15.6 14.3 14.9±0.7 Zn 426 417 448 442 447 F5B/XXX Cd — — 410 398 401±9 Cu — — 9.4 8.7 9.5±0.3 Zn 188 188 187±4 F6A/XXX Cu 32.1 32.7 34.6 32.6 32.7±1.0 Fe 176 179 173 177 177 ±4 Mn 17.4 16.3 17.4 17.4 17.2±0.4 W — — — — 168±6 F6B/XXX Cu 11.9 12.8 13.2 12.6 12.8±0.1 Fe 63.2 81.9 67.2 68.2 70.2±3.1 Mn 6.2 7.1 6.9 6.7 6.6±0.5 W — — — — 64.7±3.7 aProcedural data.bNominal data, mean±s (n=6). incorporate a procedure using an open focused-microwave the use of blank filters, quality control and spike solutions. Participants also received a customised result sheet to report digestion system. their data. Laboratories involved Samples In order to recruit participants for the interlaboratory comparison, a mail shot was sent to approximately 450 laboratories Each participant received air filter samples (described below), worldwide.Laboratories invited to take part included partici- associated blank filters, ready to run matrix matched quality pants in NIOSH’s PAT and HSE’s WASP proficiency testing control solutions and spike solutions. Quality control solutions schemes, agencies concerned with health and safety at work were supplied in order to verify instrument calibrations.and university and other research laboratories with interests Sample manipulation and work-up procedures were assessed in atomic spectrometric techniques. Sixty-seven laboratories using the spike solutions, i.e.the spike solutions were used to signed up for the trial, with 47 laboratories returning data at perform recovery tests. the time of writing. Pertinent data regarding these laboratories can be found in Tables 1 and 2. Air filter samples Prior to the start of the trial, participants received drafts of the dissolution procedures. Further instructions were sent out Each participant received six diVerent air filter samples, each at two loadings (A and B).Participants were supplied with with the samples. These included information regarding the elemental composition of the samples and solutions, indicative filters loaded with welding fume, solder fume and ore dust. Such samples represent only a small fraction of the types of concentration ranges and procedural information regarding 26 J.Environ. Monit., 1999, 1, 23–32Fig. 1 Participants’ data using ultrasonic agitation procedure. dust which can be found in workplace air, but they did contain Filter sample characterisation a fair range of metals and metalloids which have occupational Sample to sample variability. The multiport sampler was exposure limits. Further details regarding the air filter samples capable of producing near identical air filter samples.However, can be found in Table 3. slight diVerences in individual flow rates and the annular shape Participants evaluating the HNO3–HF ultrasonic agitation of the multiport sampler gave rise to variations in mass loading procedure were supplied with samples collected on 25 mm from filter to filter. Other users of such multiport sampling diameter (1.2 mm pore size) quartz fibre (QF) filters.devices15,16 have attempted to minimise this variation by Participants evaluating the other procedures were supplied applying corrections either using flow rate measurements with samples collected on 25 mm diameter (0.8 mm pore size) and/or by using gravimetric analysis. mixed cellulose ester (MCE) membrane filters.At HSL, individual filters were removed from their sampling cassettes and analysed by wavelength dispersive X-ray fluorescence spectrometry (XRFS). Details regarding the use of Air filter sample production XRFS for the analysis of air filter samples is more fully Air filter samples were collected in batches of 114 using a described in MDHS 91.11 Using XRFS, it was possible to multiport sampler.Similar samplers have been described else- measure elemental variations from filter to filter, something where.15,16 Three-part 25 mm sampling cassettes with 2 in cowl that cannot be achieved with flow rate and/or gravimetric (SKC, Blandford Forum, Dorset, UK) were used to collect measurements. The data thus obtained were then used to the samples. A welding fume box, as described in BS 7384,17 correct the participants’ results for within-batch variability on was used to collect welding fume produced under controlled an element by element basis.Results from the interlaboratory conditions. The fume was sampled into the multiport sampler comparison and from other similar multiport sampling exerthrough a length of flexible plastic hosing connected to the cises18 suggest that this elemental variability is typically less exhaust stack of the welding fume box.The refinery ore filter than 3% (one standard deviation), provided that obvious samples were produced in a two stage fashion. Initially a outliers are excluded, e.g., samples collected with partially certified bulk reference material of a geological origin (IGS blocked critical orifices.standard) was reduced in particle size using a combination of sieving and wet micromilling. Dried dust was subsequently Nominal loadings. A number of filters from each batch were analysed at HSL to provide nominal loading values. These packed into a Wright dust generator, and this was used to produce a dust cloud inside a dust box. Once again, the filters were subjected to microwave dissolution, using a procedure similar to that described above, and the resultant resultant dust cloud was sampled into the multiport sampler using a length of flexible plastic hosing.solutions were analysed using ICP-AES. A 3+1+1 mixture J. Environ. Monit., 1999, 1, 23–32 27Fig. 2 Participants’ data using hot-plate dissolution procedure.of nitric, perchloric and hydrofluoric acid was used to digest involving the use of homogeneous bulk samples. Instead the following procedure was used to process the returned data: the the filters. The performance of this procedure had previously been verified in-house.4 eVect of sample to sample variability was minimised using normalised XRFS data; blank subtraction was carried out in cases where participants reported blank values; outlier data were Sample packing and transportation rejected using quality control and spike recovery data; elemen- Air filter samples were placed in individually labelled 49 mm tary statistics were performed on the accepted data; and participlastic Petri dishes (Gelman Sciences, Ann Arbor, MJ, USA).pants’ data were compared with data obtained at HSL.Prior to shipment, each membrane filter sample was spiked with approximately 400 ml of propan-1-ol (HPLC grade). This Minimisation of the eVects of within-batch sample variability had the eVect of slightly dissolving the mixed cellulose ester Correction factors, based upon XRFS analysis, were applied filter, thus encapsulating the deposit and preventing loss of to participants’ results to minimise within-batch sample varia- sample from the filter in transit.Participating laboratories also bility. These factors were typically in the range 0.97–1.03. received a spiked blank filter to assess potential impurity levels in the propan-1-ol. Quartz fibre filters, being depth filters, did Blank subtraction not require this treatment, because the deposit is embedded in the fibres. Quality control and spike solutions were supplied Participants who noted contributions from filter blanks and/or in prewashed 30 ml Nalgene bottles (LDPE). Samples were reagents were asked to submit these data.Where appropriate, shipped to participating laboratories in Nalgene Passport UN these blanks were subtracted from the participant’s sample combination boxes by specialised courier. These combination results.boxes met the required regulatory standards for shipment of chemicals, e.g., UN transportation regulations and air ship- Rejection of outliers ment regulations. Participants’ quality control and spike recovery data were used to verify instrumental calibration and to ascertain the ability Results of the analyst to perform quantitative manipulations during the sample dissolution stage, respectively.Data returned from participants (filter results, quality control and spike recovery data) were entered into a customised Excel In order for sample data to be accepted: quality control data were required to be within ±10% of the participants’ spreadsheet. Once entered, the data set was double checked for potential transcription errors.Although established protocols mean value and spiked recovery data were required to be in the range 90–110% (and with an RSD of <10%, if replicate for statistical analysis of data returned from interlaboratory trials exist, e.g., ISO 5725,19 they are more suitable for trials data were supplied). 28 J. Environ. Monit., 1999, 1, 23–32Fig. 3 Participants’ data using hot-plate dissolution procedure. If these conditions were not met, data supplied for the randomly selected from each batch of samples were analysed. samples was closely examined and the following action was Procedural data represent the data obtained at HSL using taken: if a systematic bias was noted for quality control, spike each of the selected dissolution procedures, i.e., by HSL acting recovery and sample data, then the sample data were rejected; as a participant in the trial.These data were used as a if a systematic bias was noted for the quality control and spike benchmark to demonstrate what could be achieved using the recovery data, but data for the samples showed no systematic selected dissolution procedures. A shortage of filter samples bias, i.e., the data fell within the range obtained by other meant that only two replicate quartz filter samples were laboratories, then the data were accepted; and if high filter analysed using the ultrasonic procedure.An acute shortage of results from participants were noted, these were rejected if membrane filters meant that only single samples could be they fell outside the HSL nominal value +3s.analysed using the hot-plate and microwave sample dissolution procedures. Accepted data sets Elementary statistics were performed on the accepted data. Data presentation Mean, median, standard deviation and RSD were calculated using a customised spreadsheet for each of the twelve filter The results obtained are presented in two formats.Data samples analysed by the five dissolution procedures. obtained in-house at HSL (procedural and nominal ) are given No attempt was made to evaluate results for silver and tin in Tables 4 and 5. Participants’ data are reproduced in the as few participants returned data for these elements. The form of standardised box and whisker plots (Fig. 1–5). For quality of returned data for these elements was also poor, illustrative purposes, these plots represent all the data received, which was not unexpected.This was attributable to the use of i.e., no outliers removed. an inappropriate acid mixture and/or incompatibility of the Each figure represents participants’ data obtained using one elements concerned with certain acids. of the selected dissolution procedures.Each figure is broken down into six plots representing data for each of the six filter Comparison with HSL data types. Each individual plot shows elemental data for a particular filter type at two mass loadings ( labelled A and B). The Participants’ data were compared with two sets of data box and whisker plots follow the standard convention, i.e., obtained at HSL, termed nominal and procedural.Nominal four quartiles and median are shown. Participants’ data have data represent the data obtained at HSL using the high been normalised against the HSL nominal data with an upper performance microwave dissolution procedure (outlined and lower limit set at one standard deviation (represented by above). The data represent an estimation of the true elemental loading on each filter.Four quartz and six membrane filters the three vertical dashed lines). The relationship between the J. Environ. Monit., 1999, 1, 23–32 29Fig. 4 Participants’ data using microwave assisted dissolution procedure. X and Y variables is represented by the following equation: method was satisfactory (good agreement between participants’ data, HSL’s procedural and nominal data) for elements Y=6 [(X-nominal )/(nominal+s)-(nominal-s)] such as cadmium and zinc.This is consistent with XRD data, which showed that these elements existed as simple oxides, Participants obtained these data in a diVerent format. Data were supplied in a numerical format. For graphical comparisons, i.e., acid soluble. Poorer quality data were obtained for elements such as chromium and nickel.On occasions, results the same data were supplied in the form of bar graphs (A3 colour). Box and whiskers plots were used here in an attempt to were up to 30% lower than those obtained using the microwave assisted dissolution procedure. Preliminary work carried out produce a concise graphical representation of the data. at HSL4 investigated the eVectiveness of this procedure using milligram amounts of bulk reference materials.This showed Discussion similar trends for these more ‘refractory’ elements. Airborne particulate matter collected from the workplace atmosphere Sample morphology often contains chromium and nickel in the form of spinel Six diVerent sample matrices were examined: four welding oxides, which can be diYcult to digest.fume matrices, a silver solder fume matrix and a geological The data obtained at HSL using this ultrasonic procedure ore based matrix. The welding fume matrices were derived were slightly inferior to those obtained by the participating from flux core arc and manual metal arc welding processes. laboratories. This may in part be explained by the fact that Qualitative X-ray diVraction (XRD) identified a spinel type the majority of laboratories involved in testing this procedure oxide as the dominant crystalline phase in each of these were French and consequently, as mentioned above, experimatrices. These spinel type oxides can generally be represented enced in its use. Additionally, whilst samples digested at HSL by the formula AB2O4 (where A=Co, Fe, Mg, Mn and Zn were allowed to stand prior to analysis, thus allowing sedimenand B=Al, Cr, Co and Fe).The silver solder fume showed tation of undissolved residues, it is known that some of the crystalline phases consistent with Ag2O, CdO and ZnO. The participating laboratories homogenised their samples prior to diVraction pattern also suggested the presence of phases con- nebulisation, thus allowing the possibility that fine undissolved sistent with CdAg alloy and Ag metal.The geological ore particulates were also analysed, i.e., slurry nebulisation. based matrix, prepared from a certified reference material, IGS 26 Tin–Tungsten Ore, showed diVraction patterns consistent with the presence of SnO2, CaWO4, FeWO4 and Fe2O3. Hot-plate digestion procedures The quality of data obtained using the hot-plate procedures was Ultrasonic agitation procedure found to be good when applied at HSL.There was good agreement for most elements between HSL’s procedural data and the The quality of data obtained using this procedure was found to vary depending upon the element. The performance of the nominal data. One obvious exception was chromium.Chromium 30 J. Environ. Monit., 1999, 1, 23–32Fig. 5 Participants’ data using microwave assisted dissolution procedure. containing spinel type oxides can be diYcult to digest fully, closed microwave-assisted dissolution procedures than using other procedures, although it has been shown that equivalent especially using hot-plate digestion procedures. This is consistent with previous investigations carried out in-house.3 performance can be obtained using hot-plate procedures for many elements in the matrices examined.The ultrasonic The performance of participating laboratories in applying the hot-plate procedures was slightly inferior. Both hot-plate agitation procedure can be a rapid and eVective method for certain elements and matrices.The methods themselves were procedures require the analyst to heat samples to a ‘fuming’ end-point. Experience is important in such circumstances, as adjudged by the participants to be straightforward to follow, although other factors may hinder their usability, e.g., cost insuYcient ‘fuming’ will lower the digestion eYciency, and insuYcient/excessive ‘fuming’ will introduce an acid matrix (e.g., expense of microwave systems), safety (e.g., use of perchloric and hydrofluoric acid) and compatibility (e.g., mis-match and hence a measurement bias.It is fair to say that many laboratories analysing environmental samples using hot- requirement for hydrofluoric acid resistant nebuliser systems). plate digestions avoid using higher boiling-point acids such as perchloric acid and sulfuric acid, and this might in part account for their inferior performance.Future work A small amount of further practical work is necessary. An Closed vessel microwave-assisted digestion procedures evaluation of an open focused microwave assisted dissolution procedure is planned, and parallel investigations will The quality of data obtained using the microwave procedures was found to be good when applied at HSL.For elements re-evaluate the ultrasonic procedure with specific reference to its performance in digesting chromium containing samples. such as chromium and nickel, bound in more refractory phases, the use of perchloric and hydrofluoric acid is at times Further refinement of the current draft of the proposed International Standard will take place, to take account of required to ensure complete recoveries. The performance of participating laboratories in applying the microwave pro- comments received in the public enquiry and to ensure consistency of language between the diVerent methods.Consideration cedures was inferior to that of HSL, although the range of data (± one standard deviation) overlapped with the HSL might also be given to providing the user with guidance to help decide which is the most appropriate dissolution nominal data for many elements. procedure for a particular application.However, drafting a selection guide will not be facile, as this inherently depends Conclusions upon many factors, such as the nature of the sample matrix, equipment availability, experience of staV and safety The overall performance of participating laboratories was creditable. As expected, better performance was obtained using considerations.J. Environ. Monit., 1999, 1, 23–32 318 US National Institute for Occupational Safety and Health, Acknowledgements NIOSH Manual of Analytical Methods, US Government Printing OYce, Washington, 4th edn., 1994 DHHS Publication The authors thank S.D. Bradley (HSL), G. J. Carter (TWI), No. 94–113. K. Y. K. Chung (HSL), J. E. Chisholm (HSL), R. D. Foster 9 British Standards Institution, Sampling and Analysis of Welding (HSL) and P. R. Stacey (HSL), who assisted in practical Fume, BS 6691: Part 1, BSI, London, 1986. aspects of this work. Clerical support from P. Twigg, 10 US Occupational Safety and Health Administration, OSHA M.Turner and D. Hoyland is acknowledged. Analytical Methods Manual, USDOL/OSHA, Salt Lake City, 2nd edn., 1991. Acknowledgement of the contributions of the working group 11 Health and Safety Executive, Methods for the Determination of involved in developing ISO 15202 is also noted. Many thanks Hazardous Substances. MDHS 12/2, Chromium and Inorganic are due to the immense contributions of the participating Compounds of Chromium in Air, 1996.MDHS 42/2, Nickel and laboratories. This work was funded and carried out on behalf Inorganic Compounds of Nickel in Air (Except Nickel Carbonyl), of the Directorate of Science and Technology, the Field 1996. MDHS 91, Metals and Metalloids in Workplace Air by Operations Division and the Health Directorate of the Health X-Ray Fluorescence Spectrometry, 1998.HSE Books, London. 12 A. M. Paudyn and R. G. Smith, Can. J. Appl. Spectrosc., 1992, and Safety Executive. 37, 230. 13 M. Bettinelli, U. Baroni and N. Pastorelli, J. Anal. At. Spectrom., References 1987, 2, 485. 14 Environmental Protection Agency (US EPA) OYce of Solid 1 O. T. Butler and A. M. Howe, ICP-AES Method for Metals in Air: Waste, Microwave Assisted Acid Digestion of Siliceous and a Critical Review of Published Dissolution Procedures, HSL Organically Based Matrices, Method 3052, in Test Methods for Internal Report IR/IS/96/02, Health and Safety Laboratory, Evaluating Solid Waste Physical/Chemical Methods, SW-846, SheYeld, report available from the authors. National Technical Information (NTIS) Service, Springfield, 2 O.T. Butler, S. D. Bradley and A. M. Howe, A Revised Dissolution NTIS Order No. PB97-501928INQ, 1995. Procedure for the Determination of Nickel and Its Inorganic 15 R. Aksnes, S. Hetland and Y. Thomassen, Quality Assurance of Compounds Using Flame Atomic Absorption Spectrometry, HSL Working Environment Analyses: Interlaboratory Trials—Elements, Internal Report IR/L/IS/94/04, Health and Safety Laboratory, Norwegian National Institute for the Working Environment, SheYeld, report available from the authors. Occupational Hygiene Section, Oslo, 1990, 1992 and 1995 (in 3 O. T. Butler, S. D. Bradley and A. M. Howe, A Revised Dissolution Norwegian, except for 1990 report, HSE Translation Procedure for the Determination of Chromium and Its Inorganic No. 14280F). Compounds Using Flame Atomic Absorption Spectrometry, HSL 16 J. Anglov, E. Holst, S. Dyg and J. M. Christensen, Fresenius’ Internal Report IR/L/IS/95/12, Health and Safety Laboratory, J. Anal. Chem., 1993, 345, 335. SheYeld, report available from the authors. 17 British Standards Institution, Laboratory Methods for Sampling 4 O. T. Butler, S. D. Bradley and A. M. Howe, ICP-AES Method and Analysis of Particulate Matter Generated by Arc Welding for Metals in Air: Preliminary Tests on Bulk Reference Materials Consumables, BS 7384, BSI, London, 1991. to Test the EVectiveness of the Proposed Sample Dissolution 18 O. T. Butler, unpublished data, 1997. Procedures, HSL Internal Report IR/IS/96/04, Health and Safety 19 International Standards Organization (ISO), Precision of Test Laboratory, SheYeld, report available from the authors. Methods—Determination of Repeatability and Reproducibility for 5 K. Ashley, Electroanalysis, 1995, 7, 1. a Standard Test Method by Inter-laboratory Tests, ISO 5725, 6 L. Jalkanen and E. Hasanen, J. Anal. At. Spectrom., 1996, 11, 365. Geneva, 2nd edn., 1986. 7 Metanal Technique Operatoire Standardise�e INRS/CRAM, Technique No. 1B, Institut National de Recherche et de Securite, Vandoeuvre, 1993. Paper 8/07526C 32 J. Environ. Monit., 1999, 1, 23–

ISSN:0960-7919    

DOI:10.1039/a807526c

出版商:RSC    

年代:1999

数据来源: RSC

摘要:

Determination of Ni(CO)4, Fe(CO)5, Mo(CO)6, and W(CO)6 in sewage gas by using cryotrapping gas chromatography inductively coupled plasma mass spectrometry Jo�rg Feldmann Department of Chemistry, University of Aberdeen, Meston Walk, Old Aberdeen, UK AB24 3UE. E-mail: j.feldmann@abdn.ac.uk; Fax: +44 1224 272921 Received 17th September 1998, Accepted 17th November 1998 Evidence for the occurrence of Ni(CO)4 in addition to Mo(CO)6 and W(CO)6 in fermentation gases from a municipal sewage treatment plant is presented for the first time.The gases were sampled at the top of the sewage sludge digester using Tedlar bags, and were analysed using cryotrapping followed by gas chromatography coupled with inductively coupled mass spectrometry (GC-ICP-MS). The use of an ICP-MS as an element-specific detector gives suYciently low detection limits for metals and was coupled to a packed column gas chromatograph.This method provides information about the speciation of volatile transition metals in contrast to previously used methods for the determination of Ni(CO)4 in gas samples. The element-specific detection of three diVerent isotopes (m/z 58, 60, 62) and the correspondence of the samples’ retention times with those of the standard provided convincing evidence that Ni(CO)4 is present in the fermentation gas.The concentrations found were in the sub-ppb level, which is at least one order of magnitude lower than the threshold level of 1 ppb (v/v). In addition, Mo(CO)6 and W(CO)6 were also measured in the sub-ppb range in contrast to the absence of Fe(CO)5. The stabilities of Ni(CO)4, Fe(CO)5, and Mo(CO)6 were tested in a carbon monoxide atmosphere.In the presence of distilled water, the following order of stability was found after 11 weeks: Fe(CO)5<Ni(CO)4<Mo(CO)6. In the presence of an aqueous solution containing nickel, molybdenum, tungsten and iron, however, only Fe(CO)5 was significantly decomposed (<0.3% recovery); Ni(CO)4 and Mo(CO)6 were stable after 11 weeks.No W(CO)6 was formed. The low stability of Fe(CO)5 in the presence of water could be the reason why no volatile iron compound was found in sewage gas. This study showed that GC-ICP-MS can be employed to identify species-specific traces of metal carbonyls in process gases such as sewage gas. The analytical method used should be able to measure very Aim of investigations small concentrations of volatile nickel compounds, should Nickel tetracarbonyl is used in the manufacture of catalysts, give information about the species, and should not be limited in nickel vapour plating, as an intermediate in nickel refining by other volatile organic or organometallic compounds (the Mond process), and in the manufacture of high purity present in sewage gas.DiVerent methods have been developed nickel powder. Nickel carbonyl is one of the most dangerous in the past for continuous or spot measurements, and chemicals known, because of its lipid solubility and volatility detection limits for the following analytical methods have (bp 43 °C). It can easily be inhaled and absorbed by traversing been reported for nickel tetracarbonyl: non-specific chemithe pulmonary alveolar membranes and the blood–brain bar- luminescence, 0.01 ppb (0.07 mg m-3);4 specific for Ni(CO)4, rier.1 It exhibits acute toxicity, as well as carcinogenicity and 1 ppb (7 mg m-3);5 and as a portable system, 0.13 ppb teratogenicity.Therefore very low threshold levels are set by (0.9 mg m-3);6 mass spectrometry, 10 ppb (70 mg m-3);7 occupational health and safety bodies in diVerent countries infrared spectrophotometry, 10 ppb (70 mg m-3).8 The (e.g., US limit value (time-weighted average, TWA), 0.12 mg absorption of volatile nickel compounds into a graphite Ni m-3 (50 ppb); French valeur moyenne d’exposition (VME) furnace with subsequent detection using atomic absorption limit, 0.12 mg m-3; and Swedish level limit, 0.007 mg m-3 spectrometry is not species-specific, but has excellent detection (1 ppb)). limits because the detection system is element-specific [0.5 ng Nickel tetracarbonyl is produced by passing carbon monox- absolute mass, 10-3 ppb (0.007 mg m-3)],9 and an on-line ide over finely divided nickel.However, it is also known that preconcentration method for trapping nickel as nickel carit can be generated spontaneously in unexpected environments bonyl can detect 0.09 ng nickel as absolute mass.10 However, whenever carbon monoxide comes into contact with an active these methods are not able to separate and identify diVerent form of nickel.2 Nickel is concentrated in sewage, and values volatile nickel compounds. It was shown earlier11 that gas up to 100 mg nickel per kg of raw sewage sludge are normal.3 chromatography can be used to separate diVerent volatile After the fermentation process of this raw sludge, the nickel compounds, and therefore a combination of elementconcentration of heavy metals in the digested sludge is usually specific detection and chromatographic separation would give higher, but not for nickel (82 mg kg-1).2 Nickel occurs species information as well as excellent detection limits.mostly as organo-nickel complexes in the sewage and will be Previously described cryotrapping GC-ICP-MS was used to transformed into nickel sulfide during the fermentation identify volatile molybdenum and tungsten species as their process. However, other microbial transformations of nickel hexacarbonyls in landfill gas.Thus, the aim of this study was to identify volatile nickel metabolites, such as Ni(CO)4, in cannot be excluded. J. Environ. Monit., 1999, 1, 33–37 33sewage gases by applying this analytical technique for trace through a heated Teflon transfer line (0.3 mm od, 120 °C) to the torch of the ICP-MS (PQ2, VG Elemental, Winsford, amounts of volatile nickel compounds.UK). In addition, an aqueous solution containing 10 ng mL-1 Rh as a continuous internal standard was introduced as a wet Description of experimental procedures aerosol into the plasma using a Meinhard nebulizer. Rh can Reagents be used to monitor the stability of the ICP-MS, when gas samples are introduced into the plasma, so that ghost peaks Mo(CO)6 and W(CO)6 (both purchased from Pressure can easily be identified.Both gas flows were mixed together Chemicals, Pittsburgh, PA, USA) were used for the standard in a tee-piece (6 mm od) inserted between the spray chamber addition method to quantify the concentration of these comand the torch, replacing the quartz elbow usually in this pounds in sewage gas as well as in carbon monoxide.A 10 L position. The cryotrapping-cryofocusing GC-ICP-MS unit is gas cylinder of carbon monoxide containing Ni(CO)4, shown in Fig. 1. A thorough description of the method has Fe(CO)5, and Mo(CO)6 at unknown concentrations was used been published elsewhere.13 The operating parameters were as the diluted standard for identification purposes. NiBr2 the same as used for liquid samples (cool gas flow, 13 L min-1; (K&K Laboratories, Hollywood, CA, USA), FeSO4.7H2O auxiliary gas flow, 0.7 L min-1; nebulizer gas flow, (Fisher Scientific, NJ, USA), (NH4)6Mo7O24·4H2O, and 1.0 L min-1; power, 1350W).In a screening analysis, the WOCl4 (both Alfa Inorg. Ventron, Beverly, MA, USA) were mass range between m/z 48 to 200 was scanned using 320 ms used for the stability test.as the dwell time per channel. The following isotopes were detected in the peak hopping mode (20 ms dwell time per Sampling site channel ) for the qualitative determination of the isotopic Gas samples were collected from a municipal sewage treatment fingerprint of the gas samples: 50Cr, 52Cr, 54Cr/Fe, 55Mn, 57Fe, plant equipped with a mesophilic sewage sludge digester (Iona 58Ni, 59Co, 60Ni, 61Ni, 62Ni, 64Ni, 92Mo, 94Mo, 95Mo, 96Mo, Beach, Vancouver, Canada).Inside the pumping house, gas 97Mo, 98Mo, 100Mo, 103Rh, 180W, 182W, 183W, 184W, and 186W. pipes were connected to the top of the fermenters, from which For quantification purposes only 54Fe, 57Fe, 58Ni, 60Ni, 98Mo, gas samples containing methane and carbon dioxide were 103Rh, and 184W were measured.collected. Evidence for some leakage in the pipes was recognized by the characteristic smellf the fermentation gas in the Stability test pumping house. For this study, 10 samples were collected. Two 400 mL Schlenk flasks closed oV with a silicone septum Sampling procedure and preconcentration were filled with carbon monoxide containing Ni(CO)4, Fe(CO)5, and Mo(CO)6.One flask was filled with 100 mL The Tedlar bags, equipped with a valve, were connected with deionized water. The other flask was filled with an aqueous polypropylene (PP) tubing to a small bypass valve in the metal solution (Me-sol ) of NiBr2 (107 mg Ni L-1), pipes. The pressure in the pipe was suYcient to fill the bags FeSO4·7H2O (54 mg Fe L-1), (NH4)6Mo7O24·4H2O (123 mg with a flow rate of about 5 L min-1.The gases were collected Mo L-1), and WOCl4 (125 mg W L-1). Both flasks were directly into 80 L Tedlar bags, which had been checked for purged and filled with CO again and stirred in the dark at blank levels. The temperature of the gas was approximately room temperature for 11 weeks using a magnetic stirrer. Only 33 °C. The bags were placed in a black plastic bag to prevent 1 mL of headspace gas was withdrawn from each flask after 4 UV light from entering and stored at 4 °C.The gas samples weeks and 11 weeks using a gas tight syringe. The gases were were cryogenically preconcentrated by trapping the gases on directly injected onto the cryogenic column through a septum the first U-shaped trap filled with Chromosorb (10% SP-2100 port.The 4 week samples were used to check for leakage by 60–80 mesh, Supelco) at -78 °C (dry ice/acetone slush). This the determination of nitrogen; no leaks were observed. relatively high temperature was chosen to avoid condensation of carbon dioxide and methane, the major components of sewage gas. In a cryofocusing step, the volatile species were Results and discussion volatilized by increasing the temperature of the trap from When carbon monoxide is stored in steel gas cylinders, iron -78 °C to 150 °C with a flow rate of 133 mL min-1 He.The pentacarbonyl can be formed. Steel contains many other transfer line was heated up to 120 °C by a nichrome wire. The metals, e.g., nickel and molybdenum, so that the formation of released gases were frozen ( liquid nitrogen) onto a second Ucarbonyl compounds other than that of iron can be assumed. shaped trap (6 mm od, 31 cm length), which was packed with CO from a steel gas cylinder was sampled in a Tedlar bag.Chromosorb (10% SP-2100 45–60 mesh, 6 mm od, 31 cm Only 1 mL of CO gas was injected onto the GC column, length, Supelco, Bellefonte, PA, USA) and cooled with liquid cooled at -78 °C.After separation, signals at m/z 58, 60, 61, nitrogen. The trapping eYciency was tested for non-polar organometallic substances (SnH4 bp: -52 °C, 0.1%; Me2SnH2 bp: 35 °C, 87%; n-BuSnH3 bp: 100 °C, 100%) which are easy to handle.12 A trapping eYciency of more than 90% can be assumed for non-polar compounds with a boiling point higher than 40 °C. Analytical procedure No clean-up procedure or derivatization was performed on the gas samples in order to avoid a change in the molecular structure of volatile metal compounds.The analytical procedure applied was a combination of thermodesorption of the cryotrapped sample and separation using a non-polar chromatographic column. The column was heated exponentially from -196 to 150 °C within 3 min and the gases separated using Fig. 1 The set-up of the cryotrapping-cryofocusing GC-ICP-MS unit. an He flow of 133 mL min-1. The reproducibility of this The transfer line, tubings and traps were electrically heated by a procedure is so good that the variation of the retention times nichrome wire. A, cryofocusing; B, measurements and simultaneous cryotrapping of a new sample. was less than 3 s.The separated sample was transported 34 J. Environ. Monit., 1999, 1, 33–3762, and 64 were recorded at a retention time of 60 s. The intensities of all the peaks can be fitted to the relative abundance of naturally occurring nickel. At 110 s, signals at m/z 54, 57, and 58 were recorded. 56Fe was not measured, because of the high background from 40Ar16O+ in the plasma.However, the isotopic fingerprint fits the isotope pattern of iron. At 170 s, all masses from molybdenum recorded signals according to the natural isotopic fingerprint. The metal carbonyls were separated according to their extrapolated boiling points [Ni(CO)4, log p=7.690-1519/T , bp 42.7 °C; Fe(CO)5, log p=8.3098 – 2050.7/T , bp 104.7 °C; Mo(CO)6, log p= 11.174 – 3561.3/T , bp 156.3 °C; W(CO)6, log p=11.523 – 3872/T , bp 174.9 °C; p is the partial pressure in mmHg and T is the temperature in °C].The identification of the metal species is based on the chromatographic separation and on the element-specific detection (ICP-MS). The chromatographic separation showed a linear relationship (R2=0.9832) between the boiling points or the extrapolated boiling points of volatile standards (Ni(CO)4, Fe(CO)5,Mo(CO)6, W(CO)6) and their retention times [bp=1.048·r.t.-22.19; bp, boiling point (°C); r.t., retention time (s)].The separation for the neutral metal carbonyls shows the same separation characteristics as for neutral methylated metal and metalloid species, such as SnH4, Me2 SnH2, Me4 Sn, AsH3, Me3 As, etc.). This relationship can be used to identify unknown peaks according to their element-specific detection and their correlated boiling point.Mo(CO)6 standard gave the same retention time as the unknown Mo peak (170 s). Using standard addition methodology, 0.14–0.19 ppb (v/v) (0.6–0.8 mg Mom-3) was determined to be the concentration of Mo(CO)6 in the CO. Nickel and iron carbonyls were quantified by a semi-quantitative Fig. 2 The detection of 300 ng Fe(CO)5, 0.14 ng Ni(CO)4, and 0.6 pg Mo(CO)6 in carbon monoxide stored in a gas cylinder. method using aqueous nickel and iron standards. It was shown earlier14 that this method can produce an uncertainty of about ±30% for volatile metal( loid) compounds. The amounts of isotopes matched the isotope ratios of the naturally occurring Ni(CO)4 and Fe(CO)5 were determined to be 49–54 ppb molybdenum and tungsten used as the standards, as shown (0.13–0.14 mg Ni m-3) and 80–148 ppm (200–370 mg earlier for landfill gas.16 The peak at the retention time of 60 s Fe m-3).The chromatograms measured simultaneously are showed matching at m/z 58, 60, 61, and 62. The occurrence shown in Fig. 2. The detection limit for a volatile molybdenum of a volatile sulfur compound with a boiling point of about compound was below 0.1 pg when 3s of the baseline was 40–45 °C could cause the high intensity at m/z 64 by forming considered.Nickel and especially iron were very much aVected 32S32S+ and/or 32S16O2+ (Fig. 4). The amount of Ni(CO)4 in by molecular interferences in the plasma of the ICP-MS. the sewage gas could only be assumed using the semi- According to the semi-quantification method, the detection quantitative method to be between concentrations of 0.5 and limits can be assumed to be two orders of magnitude higher 1.0 mg Ni(CO)4 m-3 (0.07–0.14 ppb).The amount of than the detection limits of Mo. Conservative detection limits Mo(CO)6 was slightly higher (3.0–3.6 mg Mo(CO)6 m-3; of 10 pg Ni absolute could be assumed for volatile nickel and 0.25–0.30 ppb) and W(CO)6 was determined in the 100 pg Fe for volatile iron compounds.If only 1 L of gas is 0.01–0.015 mg W(CO)6 m-3 range (0.0006–0.001 ppb). How- sampled, a detection limit of 0.01 mg m-3 (approximately ever, no volatile species of iron, chromium, cobalt, and manga- 0.004 ppb) can be calculated. Since detection limits depend on nese could be detected. the absolute mass of volatile nickel, the lowest concentration While the tungsten concentration found was similar to the in a gas sample can easily be reduced to 0.0004 ppb when the concentration in landfill gas, the concentration of volatile gas volume has been increased to 10 L.These detection limits molybdenum in the sewage gas was one order of magnitude would be comparable to those reported earlier14 for other higher than that reported in landfill gas.16 The nickel concen- volatile metals (Sn, Hg, Pb, Bi) and metalloids (As, Se, Sb, trations were one order of magnitude lower than the threshold Te) as published by Donard and co-workers.15 These detection level of 7 mg m-3 [1 ppb (v/v)]. However, the concentrations limits for the speciation of nickel are among the lowest ever measured (0.5–1.0 mg m-3) are three orders of magnitude reported and could be used to determine volatile nickel, iron, higher than the reported concentrations of volatile nickel molybdenum, chromium, and tungsten compounds in unexpeccompounds, assumed to be Ni(CO)4, in urban air ted environments such as sewage treatment plants.(0.00014–0.0048 mg m-3).17 Since these gases were leaking into The sewage gas samples were preconcentrated and analysed workplace air, it would be necessary to monitor workplace air within 4 h after sampling at the sewage treatment plant.Up for these compounds. However, these data show that the to 1 L of sewage gas was preconcentrated onto the column, concentration measured in the sewage gas will be negligible which was cooled at -78 °C.The identification of the nickel when it undergoes fast dilution in workplace air. Stability tests carbonyls was rather diYcult because the sewage gas contains for these volatile carbonyl complexes were performed in order a lot of other organic and organometallic compounds, which to shed some light on their stability in the presence of distilled can form molecular clusters in the plasma of the ICP-MS.water and a metal containing solution (Me-sol ) under oxygen- However, signals for tungsten, molybdenum, and nickel were free and dark conditions. The headspaces of the flasks, which recorded. The traces for m/z 58, 60, and 62 are shown in contained the metal carbonyls, were sampled after 11 weeks Fig. 3. Iron pentacarbonyl could not be detected in the gas. The fingerprint for the diVerent molybdenum and tungsten and analysed for volatile Ni, Fe, Mo, and W compounds. The J. Environ. Monit., 1999, 1, 33–37 35with the metal solution, and no Fe(CO)5 was detectable in the presence of pure water. The Ni(CO)4 concentration did not decrease in the presence of the metal solution; in fact, a slightly but not significantly higher concentration was determined for Ni(CO)4.In contrast, only 0.7% of the Ni(CO)4 could be recovered in the headspace after 11 weeks in distilled water. The amount of Mo(CO)6 remaining in both flasks was the same as the initial concentration in respect of the error of ±30% during the experiment. No W(CO)6 was formed in these experiments. The results of these stability tests indicate that iron pentacarbonyl is not stable in the presence of water, which might be the reason why no volatile iron compound was determined in the sewage gas.It seems that Mo(CO)6 was more stable under these conditions in comparison to the nickel and iron compounds. Nickel carbonyl seemed to be stable in the presence of a nickel solution in a CO atmosphere, and less stable if no nickel was present in the aqueous phase. It is well known that Ni(CO)4 can be synthesized if nickel and sulfide are present in aqueous solution.18 As an intermediate, the sulfide will be oxidized to elemental sulfur and immediately reduced by CO to sulfide again, and thus sulfide acts as a catalyst.Under 1 bar CO, NiS in water has been reported to be quantitatively transformed to Ni(CO)4.18 So far nothing is known about the transformation of iron and molybdenum into their volatile neutral carbonyls in aqueous solution.As the conditions in the fermentation tank of a sewage plant are reducing and free sulfide is available, a purely chemical reaction could be responsible for the generation of Ni(CO)4 at low temperatures (35 °C). Nickel as well as molybdenum and tungsten can be reduced by a suitable reducing agent (e.g., hydrogen produced by the micro-organisms in the fermentation process) and the resulting active metal can directly react with carbon monoxide. However, it cannot be excluded that microbial transformations of insoluble or soluble nickel compounds may be responsible Fig. 3 Detection of Ni(CO)4 in 100 mL sewage gas measured at m/z for the generation of the volatile nickel carbonyl in the 58, 60, and 62 using GC-ICP-MS.The first peak at m/z 58 might not fermentation process. Furthermore, nickel and molybdenum be a nickel signal if the isotope ratio is considered. are essential elements for methanogens, e.g., the nickel tetrapyrrole prosthetic group of methyl CoM reductase is an essential enzyme of methanogenesis.In fact, one of the Ni ions in CO dehydrogenase appears to bind CO and a methyl group. If these enzymes break down, a CO transfer to the released metal is not unlikely. This study showed that the GC-ICP-MS method can be employed to identify the occurrence of volatile nickel compounds in sewage gas. The stability tests shed some light on why no iron pentacarbonyl can be detected in landfill and sewage gas.However, how nickel tetracarbonyl is formed, i.e., in a purely chemical reaction or by the action of microbial Fig. 4 Isotopic fingerprint of the signal at 60 s retention time by transformation, cannot yet be answered. determination of Ni(CO)4 in sewage gas using GC-ICP-MS (standard: Ni(CO)4 in CO gas cylinder).Acknowledgements quantified concentrations in Table 1 were compared to the initial concentrations of the carbonyls in CO. The recovery I gratefully thank Prof. F. W. Sunderman Jr. for useful discussions. I would also like to address my special thanks to rate for Fe(CO)5 was determined to be only 0.3% of the concentration of Fe(CO)5 in CO before the flask was filled Prof.W. R. Cullen, who gave me the opportunity to be part Table 1 Metal carbonyls in carbon monoxide gas stored dry in metal gas cylinders, and their concentration after 11 weeks in contact with distilled water and a metal containing solution (Me-sol ) in glass flasks. The concentrations measured in sewage gas and landfill gas are also shown. Concentrations are given in ppb (v/v) Medium Fe(CO)5 Ni(CO)4 Mo(CO)6 W(CO)6 CO (cylinder) 80000–148000 49–54 0.14–0.19 n.d.CO (Me-sol )a 340 60 0.3 n.d. CO (dist. water)a n.d. 0.35 0.2 n.d. Sewage gas n.d. 0.07–0.14 0.25–0.30 0.0006–0.001 Landfill gas16 n.d. n.d. 0.047–0.071 0.0006–0.0012 aAfter 11 weeks; n.d., not detected. 36 J. Environ. Monit., 1999, 1, 33–377 J. H. Campana and T. H. Risby, Anal. Chem., 1980, 52, 468.of his research group and for his support and interest in this 8 R. S. McDowell, Am. Ind. Hyg. Assoc. J., 1971, 32, 621. work. Finally, I thank the Iona Beach Sewage Treatment Plant 9 L. Filkova and J. Ja�ger, J. Chem. Listy, 1986, 80, 1207. for the opportunity to sample the sewage gas. 10 D. Erber and K. Cammann, Analyst, 1995, 120, 2699. 11 F. W. Sunderman, Jr., Arch. Environ. Health, 1968, 16, 836. 12 J. Feldmann, PhD Thesis, Cuvillier, Go� ttingen, Germany, 1995. References 13 J. Feldmann and W. R. Cullen, Environ. Sci. Technol., 1997, 31, 2125. 1 F. W. Sunderman, Jr. and A. Oskarsson, in Metals and Their 14 J. Feldmann, J. Anal. At. Spectrom., 1997, 12, 1069. Compounds in the Environment, ed. E. Merian, VCH, Weinheim, 15 C. Pe�cheyran, C. R. Quetel, F. M. Matin Lecuyer and O. F. X. 1991, pp. 1101–1126. Donard, Anal. Chem., 1998, 70, 2639. 2 S. Hetland, I. Martinsen, B. Radziuk and Y. Thomassen, Anal. 16 J. Feldmann and W. R. Cullen, Environ. Sci. Technol., 1997, 31, Sci., 1991, 7, 1029. 2125. 3 R. C. Kistler, F. Widmer and P. H. Brunner, Environ. Sci. 17 L. Filkova and J. Ja�ger, C. Hygenia, 1986, 31, 255. Technol., 1987, 21, 704. 18 H. Behrens and E. Eisenmann, Z. Anorg. Allg. Chem., 1955, 278, 4 D. H. Stedman and D. A. Tammaro, Anal. Letters, 1976, 9, 81. 155. 5 P. M. Houpt, A. Van Der Waal and F. Langeweg, Anal. Chimica Acta, 1982, 136, 421. 6 D. A. Hikade, D. H. Stedman and J. G. Walega, Anal. Chem., 1984, 56, 1629. Paper 8/07277I J. Environ. Monit., 1999, 1, 33&nda

ISSN:0960-7919    

DOI:10.1039/a807277i

出版商:RSC    

年代:1999

数据来源: RSC

摘要:

A diVusive sampling device for the determination of formaldehyde in air using N-methyl-4-hydrazino-7-nitrobenzofurazan (MNBDH) as reagent Andrea Bu�ldt,a Roger Lindahl,b Jan-Olof Levinb and Uwe Karst*a aWestfa�lische Wilhelms-Universita�t Mu� nster, Anorganisch-Chemisches Institut, Abteilung Analytische Chemie, Wilhelm-Klemm-Str. 8, 48149 Mu�nster, Germany bNational Institute for Working Life, Department of Chemistry, P.O. Box 7654, 90713 Umea° , Sweden Received 1st October 1998, Accepted 2nd December 1998 A new method utilizing the diVusive sampling of formaldehyde in air has been developed. Formaldehyde is sampled with the use of a glass fiber filter impregnated with N-methyl-4-hydrazino-7-nitrobenzofurazan (MNBDH) and phosphoric acid. The formaldehyde hydrazone formed is desorbed from the filter with acetonitrile and determined by high-performance liquid chromatography (HPLC) with UV/visible detection at 474 nm.The sampling rate was determined to be 24.7 mL min-1 with a relative standard deviation of 7% for 48 experiments. The measured sampling rates were not dependent on the formaldehyde concentration (0.1–1.0 mg m-3), sampling time (15–482 min) or relative humidity (20–85%).The detection limit was 70 mg m-3 for a 15 min sampling period and 2 mg m-3 for an 8 h sampling period. Therefore, a diVusive sampler containing a filter coated with Introduction a reagent which reacts as fast as DNPH with formaldehyde Formaldehyde is an important industrial chemical, a well- and is less susceptible to interferences by oxidants would be a known irritant, and a suspected carcinogen.1 Occupational great improvement.N-Methyl-4-hydrazino-7-nitrobenzoexposure occurs in the range from 0.1 to 5 ppm in air,1 and furazan (MNBDH) has been studied recently as a reagent levels from 0.01 to 0.1 ppm are often found in oYces and with reduced interferences by ozone and nitrogen dioxide.15 It homes.2 A very low occupational threshold value for formal- reacts with these oxidants to give only one product, N-methyldehyde is recommended in most countries [e.g., 0.75 ppm in 4-amino-7-nitrobenzofurazan (MNBDA).In this work, the USA (value given by the Occupational Safety and Health MNBDH is investigated as a potential alternative to DNPH Administration, OSHA) and 0.5 ppm in Germany3]. in diVusive sampling devices.Therefore, reliable and accurate methods for the determination of formaldehyde are needed. Experimental section A large number of methods for the determination of formaldehyde in air are already known. Many of these methods are Chemicals based on direct photometric4,5 or fluorimetric6,7 measurements. Solvents used for HPLC analysis were acetonitrile (HPLC However, chromatographic methods with UV/visible detecgrade, Rathburn, Walkerburn, UK), water (purified by use of tion8 or fluorescence detection9 are advantageous for the Milli-RQ systems, Millipore, Bedford, MA, USA), acetic acid identification of individual aldehydes.One of the most widely (Merck, Darmstadt, Germany) and triethylamine (Fluka, Neu- used methods is high-performance liquid chromatographic Ulm, Germany).Formaldehyde 2,4-dinitrophenylhydrazone (HPLC) determination using 2,4-dinitrophenylhydrazine for calibration was prepared from formaldehyde (37%, p.a., (DNPH) as derivatization reagent for formaldehyde. Sampling Merck), 2,4-dinitrophenylhydrazine (p.a., Fluka) and concen- of formaldehyde in air can be performed using solutions of trated HCl (Fluka) and recrystallized twice from ethanol DNPH in impingers8 or solid sorbents coated with DNPH, (Merck).Formaldehyde MNBDhydrazone for calibration was including test tubes for pumped sampling.10 However, prepared from formaldehyde (35%, p.a., Merck) and N- impingers are not convenient for personal monitoring. The methyl-4-hydrazino-7-nitrobenzofurazan, which was prepared use of solvent-free test tubes constitutes a great improvement, from 4-chloro-7-nitrobenzofurazan (Fluka) and methylhydra- but these methods also require pumped sampling.zine (Aldrich Chemie, Steinheim, Germany).15 For coating In recent years, diVusive (passive) sampling has been filters, phosphoric acid (p.a., Merck), glycerol (p.a., May and recognized as an eYcient alternative to pumped sampling.11 Baker, Dagenham, UK), ethanol (99.99%, Merck) and aceto- Of the diVerent constructions proposed for the diVusive sam- nitrile (HPLC Grade S, Rathburn) were used.pling device, the sampler investigated in ref. 12 with a DNPH coated filter has been established as that with the best proper- Synthesis ties for collecting formaldehyde. However, problems occur when formaldehyde has to be determined in air which also N-Methyl-4-hydrazino-7-nitrobenzofurazan (MNBDH).15 contains oxidants such as nitrogen dioxide or ozone.10,13,14 Methylhydrazine (2.24 mL) (0.04 mol ) in 100 mL methanol Both reagent and formaldehyde hydrazone are oxidatively was added dropwise to a solution of 1 g (0.005 mol) 4-chloro- 7-nitrobenzofurazan in 80 mL chloroform.After heating to decomposed.J. Environ. Monit., 1999, 1, 39–43 39reflux for 20 min, the solution was cooled and MNBDH was precipitated as a red crystalline material. The precipitate was filtered oV and washed with methanol. The yield was 48%. The purity of the product was examined by means of HPLC. The product was fully characterized by means of 1H NMR, MS, IR, UV and elemental analysis: 1H NMR (CDCl3) d 3.89 (3 H, s, N-CH3), 4.70 (2 H, s, NH2), 6.63 (1 H, d, J=9.4 Hz, C5-H), 8.46 (1 H, J=8.9 Hz, C6-H);MS m/z 209 (M+, 100%), 194 (M+-CH3, 63%), 164 (194-NO, 41%), 132 (88%), 118 (48%); IR (KBr pellet) 3334, 1639, 1555, 1459, 1426, 1322, 1295, 1279 cm-1; UV (CH3CN) lmax 486 nm, e (lmax) 21 600 Fig. 1 DiVusive sampler for formaldehyde (GMD sampler).L mol-1 cm-1.Analysis: calculated for C7H7N5O3: C, 40.20%; H, 3.37%; N, 33.48%; found: C, 40.13%; H, 3.60%; N, 33.51%. diameter of 1.0 mm. The filter beneath the holes is used for Formaldehyde MNBDhydrazone.15 N-Methyl-4-hydrazino- sampling (sampling filter), and the second is used to quantify 7-nitrobenzofurazan (100 mg) (4.8×10-4 mol) was dissolved the formaldehyde blank of the filter (control filter).A sliding in 0.7 mL water, 0.5 mL sulfuric acid and 2.5 mL 95% ethanol. cover is used to seal the holes when the sampler is not in use. A 50% molar excess of formaldehyde (7.2×10-4 mol) was The sampler is available from GMD Systems, Inc., added and the hydrazone was precipitated as a reddish mate- Hendersonville, PA, USA). The sampling rate (SR) for the rial. The precipitate was filtered oV and washed first with a 5 diVusive samplers was calculated according to Fick’s law,17 mass% aqueous solution of sodium bicarbonate until no from the cross-sectional area (A) in cm2 and the diVusion path further development of carbon dioxide was observed, and then length (L ) in cm: with distilled water.The product was recrystallized from SR (mL min-1)=D (cm2 s-1)×A (cm2)×L-1 (cm-1)×60 ethanol. The yield was 70%.The reaction product was fully characterized by means of 1H NMR, MS, IR, UV and As A and L are physical parameters associated with the elemental analysis: 1H NMR (CDCl3) d 4.03 (3 H, s, N-CH3), sampler construction, the sampling rate SR is constant for a 6.86 (d) and 7.04 (d) (2 H, J=9.7 and 9.4 Hz, NCH2), 7.40 selected analyte and diVusive sampler.This calculated value (1 H, d, J=8.9 Hz, C5-H), 8.53 (1 H, d, J=8.8 Hz, C6-H); diVers from experimentally determined sampling rates where MS m/z 221 (M+, 81%), 145 (51%), 117 (100%); IR (KBr diVusive samplers have been exposed in atmospheres of known pellet) 3023, 2969, 1616, 1541, 1496, 1320, 1186, 1079, analyte concentrations. An explanation for this is given in 1001 cm-1; UV (CH3CN) lmax 474 nm, e (lmax) ref. 18. 24 700 L mol-1 cm-1. Analysis calculated for C8H7N5O3: C, 43.44%; H, 3.19%; N, 31.66%; found: C, 43.29%; H, 3.24%; Generation of standard atmospheres of formaldehyde N, 30.80%. Gaseous formaldehyde was generated by decomposition of paraformaldehyde and permeation through a silicone tube (id Coated filters for pumped sampling 10 mm, od 14 mm, length 41 mm) as shown in Fig. 2.The DNPH (300 mg) was dissoheating in 0.5 mL concen- temperature of the permeation device was controlled and trated phosphoric acid (85%), 1.5 mL ethanol containing 20% varied between 54 and 83 °C for diVerent runs. The weight glycerol and 9 mL acetonitrile. Glass fiber filters (13 mm in loss of the permeation device was used to calculate the diameter, (type AE, 0.3 mm pore size, SKC, Inc., PA, USA) concentration in the exposure chamber.The air flow of were immersed in the solution and immediately removed again. 0.4 L min-1 passing the permeation device was further mixed The filters were then allowed to dry on a glass surface at room with controlled humidified air. The total air flow in the temperature and stored in a refrigerator.exposure chamber was 40 L min-1, which corresponds to an air velocity of 0.3 m s-1. The Teflon exposure chamber, con- Coated filters for diVusive sampling structed for sampling of 6 diVusive samplers and with ports for pumped sampling with the reference method, has been MNBDH (180 mg) was dissolved with heating in 0.3 mL described previously.16,18 concentrated phosphoric acid (85%), 0.7 mL ethanol containing 20% glycerol and 20 mL acetonitrile.Glass fiber filters Laboratory validation of the samplers (2×2 cm) were cut from round filters (type AE, 0.3 mm pore size, diameter 25 mm, SKC, Inc., PA, USA). These were then For all experiments regarding the recovery rate of formaldipped into the coating solution and allowed to dry on a glass dehyde on the MNBDH diVusive sampler, the samplers were surface at room temperature.One filter was placed under the exposed in a sampling chamber,16 six at a time, to formalsampling part of the sampler and another one under the dehyde levels from 0.1 to 1.0 mg m-3, with sampling times control part. between 15 min and approximately 8 h. The relative humidity was varied between 20% and 85%.The samplers were oriented Pumped sampling parallel to the air stream. Three pumped samples were taken For pumped sampling, the 13 mm diameter DNPH coated filters were used in two-section polypropylene filter holders (No. 225–32, SKC, Inc., PA, USA).16 For all measurements, collecting and control filter cassettes were connected in series to identify incomplete recovery on the collecting cassette.DiVusive sampling The diVusive sampler is shown in Fig. 1. The housing, measuring 60×30×5 mm, is made of polypropylene. Two impregnated filters are placed beneath a 2.9 mm thick screen. The Fig. 2 Formaldehyde generation device and exposure chamber. screen has, within an area of 20×20 mm, 112 holes with a 40 J. Environ. Monit., 1999, 1, 39–43simultaneously from the sampling chamber with a flow of 100 mL min-1.Exposure of the diVusive samplers to ozone Six diVusive samplers were first exposed to formaldehyde (1 mg m-3) for one hour. Afterwards, three of these were exposed to an ozone atmosphere (1.8 mg m-3) for two hours. HPLC instrumentation A Waters HPLC system (Milford, MA, USA), consisting of two pumps (model 510), a WISP-710B autosampler, a Waters 486 UV/visible detector and the Millennium Software Version 2.15 was used.The column material was Nova Pak RP-18 (Waters): particle size, 4 mm; column dimensions, 250 mm×4.6 mm. HPLC analysis The formaldehyde DNPhydrazone and the formaldehyde MNBDhydrazone were eluted from the filter by shaking with 3 mL of acetonitrile in a 4 mL glass vial; 10 mL of this solution were injected into the HPLC.The analysis of the DNPH coated filters was carried out with an isocratic mobile phase consisting of 60% acetonitrile and 40% water with a flow rate Fig. 3 Chromatograms of desorbed MNBDH filters of a diVusive of 1 mL min-1. The detection wavelength was 365 nm. The sampler: blank (full line) and an air sample containing 0.98 mg m-3 MNBDH coated filters were analyzed with an isocratic mobile formaldehyde (broken line).Duration of exposure was 481 min. phase consisting of 45% acetonitrile and 55% buVered water [composition: 500 mL water with 2415 mL triethylamine and Eight diVerent experiments were carried out to investigate 975 mL acetic acid (pH#7.5)] with a flow rate of 1 mL min-1. the recovery of formaldehyde.The conditions chosen for the The detection wavelength was 474 nm. individual measurements are described in Table 1. The diVusive sampler was partially tested according to EN 838.19 The Results formaldehyde concentrations in the exposure chamber were gravimetrically determined by measuring the weight loss of MNBDH was synthesized in a nucleophilic substitution reacthe permeation device and the air flow in the exposure chamber tion of N-methylhydrazine and 4-chloro-7-nitrobenzofurazan: (a). The values obtained with the pumped reference method (b) were corrected for a 95% recovery, found in previous studies.16,20 The reference values were mainly within±10%, as can be seen in Table 1, which verifies the gravimetrically determined values used for all calculations.The MNBDH coated diVusive samplers were exposed to the standard formaldehyde concentrations simultaneously with the DNPH pumped samplers. Table 2 gives the experimentally The corresponding formaldehyde MNBDhydrazone was pre- determined sampling rates calculated with the known analyte pared by reacting MNBDH with formaldehyde in the presence concentrations obtained gravimetrically.The results were of acid as catalyst: obtained from a series of experiments with diVerent formaldehyde concentrations, sampling times and relative humidities. The collecting filter and the control filter of each diVusive sampling device were eluted separately and injected into the HPLC system. In every case, blank values could be found on the control filter.Two reasons are responsible for this fact: firstly, the GMD sampler is not completely tight and leakage may occur beneath the sliding cover and between the screen and the badge housing; the leakage during sampling to the control filter is about 5% according to ref. 18; secondly, some This reaction can be utilized to collect formaldehyde on diVusive sampling devices. As the collection of formaldehyde formaldehyde MNBDhydrazone is formed during the coating of the filters due to the ubiquitous occurrence of formaldehyde.is well known using DNPH, a pumped sampling method with DNPH coated filters is used as reference method to validate The leakage is incorporated in the experimentally determined sampling rate since the amount on the control filter is always the new MNBDH diVusive sampler.Fig. 3 shows a chromatogram of the eluate of a MNBDH coated diVusive filter after subtracted from the amount on the sampling filter. Due to the blanks, problems may occur in experiments with low formal- exposure to formaldehyde containing air and the corresponding eluate of the control filter. As can be seen, the formaldehyde dehyde concentrations and short sampling times (measurement 1).In this case, the formaldehyde MNBDhydrazone on hydrazone is separated from the reagent very well. To investigate the reproducibility of the chromatographic analysis, the the control filter was about 50% of the value found on the sampling filter. This resulted in a high relative standard eluate of one filter was injected into the HPLC system ten times.The evaluation via the peak areas results in a relative deviation (13%). All other measurements show that the sampling rate was not dependent on the relative humidity, sampling standard deviation of 0.8%. This value proves the very good reproducibility of the chromatographic analysis. time or formaldehyde concentration. The mean sampling rate J. Environ. Monit., 1999, 1, 39–43 41Table 1 Recovery of formaldehyde as 2,4-dinitrophenylhydrazone obtained by the gravimetrically determined formaldehyde concentration (a) in comparison with the pumped sampling method (b) in eight diVerent experiments Determined HCHO HCHO concentration/mg m-3 concentration/ using the DNPH pumped mg m-3 obtained method (b) (corrected Recovery RSD (%) Measurement RH (%) ST/min gravimetrically (a) value) (%) (n=3) 1 20 15 0.116 0.100 86 8 2 20 478 0.116 0.111 96 3 3 85 60 0.116 0.108 93 3 4 85 475 0.116 0.101 87 4 5 20 16 1.130 1.051 93 5 6 20 481 1.030 1.032 100 1 7 85 15 1.030 1.061 103 1 8 85 482 1.030 1.084 105 1 RH, relative humidity; ST, sampling time; RSD, relative standard deviation; n, number of experiments. Table 3 Recovery of formaldehyde on the diVusive sampling devices Table 2 Experimentally determined sampling rates by means of the MNBDH coated diVusive sampling device RSD (%) Measurement Recovery (%) (n=6) RSD (%) Measurement SR/mL min-1 (n=6) 1 93 13 2 84 4 1 23.8 13 2 23.0 4 3 102 9 4 98 9 3 25.7 9 4 24.7 9 5 90 8 6 101 4 5 23.3 8 6 25.5 4 7 104 5 8 99 4 7 26.3 5 8 24.9 4 RSD, relative standard deviation; n, number of experiments.SR, sampling rate; RSD, relative standard deviation; n, number of experiments. was 24.7 mL min-1 with a relative standard deviation of 7% for 48 experiments. This value coincides well with older publications which reported a sampling rate of 25.2 mL min-1 12 obtained by means of DNPH coated diVusive samplers. The European Committee for Standardization (CEN) has published Workplace Atmospheres—General Requirements for the Performance of Procedures for the Measurement of Chemical Products (EN 482).21 This document defines the relative overall uncertainty (ROU) by combining bias and precision according to the formula: ROU= |x: -xref|+2s xref ×100 where x: is the mean value of repeated measurements, xref is the true or accepted reference value of the concentration and s is the standard deviation of the measurements.The ROU is used to specify the performance requirements of a measurement method. These requirements vary depending on the measurement task. The ROU must be 30% within the measuring range of 0.5 to 2 times the limit value, and 50% within 0.1 to 0.5 times the limit value. The ROU for the diVusive sampling of formaldehyde with MNBDH impreg- Fig. 4 Chromatogram of an eluted filter which was only exposed to nated filters was calculated to be 14%, which easily meets the formaldehyde (full line) and a chromatogram of an eluted filter which CEN requirements for a measurement method. was exposed to both formaldehyde and ozone (dotted line). Another way of interpreting the results involves the determination of the recovery rate of formaldehyde on the MNBDH coated diVusive sampling devices based on the supposition formaldehyde with the new reagent.Furthermore, the results prove that the sampling rate is not dependent on the reagent. that the sampling rate of formaldehyde must be 25.2 mL min-1, which was found by means of DNPH coated The use of a personal diVusive sampling device requires a high storage stability of the exposed samplers, because it is diVusive sampling devices.12 Table 3 shows the results of this method of interpretation.The mean recovery of formaldehyde not always possible to analyze the filters directly after exposure. To investigate this, the exposed samplers were stored in sealed on the diVusive sampler is 96% with a standard deviation of 7%.These results also show the possibility to determine bags made of laminated aluminum. Some were placed in a 42 J. Environ. Monit., 1999, 1, 39–43refrigerator, and others were stored at room temperature. The ferences when using MNBDH coated diVusive samplers compared with DNPH coated diVusive filters. analysis of the filters was carried out after five days.Once formed, the hydrazone is stable on the filter, since no decrease in recovery of formaldehyde hydrazone was noted for both Acknowledgements the cold stored filters and those stored at room temperature. Financial support of parts of this work by the European The storage stability of the diVusive samplers before expo- Commission (‘Aldehydes’ project, SMT4-CT97–2190) and by sure was investigated. Some samplers were stored in a refrigerthe Fonds der Chemischen Industrie (Frankfurt, Germany) is ator and some were stored at room temperature for two gratefully acknowledged.months and then exposed to formaldehyde. The analysis of these filters showed that the samplers stored in a refrigerator References gave a good recovery of formaldehyde. The sampling rate was determined to be 26.7 mL min-1 with a relative standard 1 R.W. Hart, A. Terturro and L. Neimeth, Environ. Health deviation of 5% for 6 experiments. The other samplers that Perspect., 1984, 58, 323. were stored at room temperature for a long time gave lower 2 T. H. Stock and S. R. Mendez, Am. Ind. Hyg. Assoc. J., 1985, 46, 313. sampling rates. This shows that the filters must be stored in a 3 Deutsche Forschungsgemeinschaft, MAK- und BAT-Werte-Liste refrigerator to give good results. 1997,Wiley,Weinheim, 1997. The stability of formaldehyde MNBDhydrazone on the 4 R. R. Miksch and W. A. Douglas, Am. Ind. Hyg. Assoc. J., 1982, diVusive samplers in the presence of ozone was also investi- 43, 362. gated. For this purpose, six diVusive samplers were first 5 R.R. Miksch, D. W. Anthon, L. Z. Fanning, C. D. Hollowell, K. Revzan and J. Glanville, Anal. Chem., 1981, 53, 2118. exposed to formaldehyde. Afterwards, three of these were 6 I. Ahonen, E. Priha and M.-L. A� ija�la�, Chemosphere, 1984, 13, 521. exposed to ozone. All filters were eluted and the eluate was 7 P. Bisgaard, L. Molhave, B. Rietz and P. Wilhardt, Am. Ind. Hyg. injected into the HPLC system.Fig. 4 shows a chromatogram Assoc. J., 1984, 45(6), 425. of an eluted filter which was only exposed to formaldehyde 8 K. Fung and D. Grosjean, Anal. Chem., 1981, 53, 168. and a chromatogram of an eluted filter which was exposed to 9 W. Schmied, M. Przewosnik and K. Ba�chmann, Fresenius’ Z. both formaldehyde and ozone. As can be seen, only one Anal. Chem., 1989, 335, 464. 10 W. Po� tter and U. Karst, Anal. Chem., 1996, 68, 3354. product is formed when MNBDH reacts with ozone. This 11 J. O. Levin and R. Lindahl, Analyst, 1994, 119, 79. was identified as N-methyl-4-amino-7-nitrobenzofurazan 12 J. O. Levin, R. Lindahl and K. Andersson, Environ. Technol. Lett., (MNBDA).15 As the peak area of the hydrazone in the 1988, 9, 1423. chromatogram has not decreased, the formaldehyde 13 R.R. Arnts and S. B. Tejada, Environ. Sci. Technol., 1989, 23, MNBDhydrazone is considered to be stable in the presence of 1428. 14 D. F. Smith, T. U. Kleindienst and E. E. Hudgens, J. Chromatogr., ozone. The evaluation of the chromatograms led to the 1989, 483, 431. following sampling rates for formaldehyde: 24.3 mL min-1 15 A. Bu� ldt and U.Karst, German Patent, DE 198 00 537.7, 1998. with a relative standard deviation of 1% for the filters which 16 J. O. Levin, R. Lindahl and K. Andersson, J. Environ. Sci. were only exposed to formaldehyde and 24.6 mL min-1 with Technol., 1986, 20, 1273. a relative standard deviation of 3% for the filters which were 17 V. Rose and J. L. Perkins, Am. Ind. Hyg. Assoc. J., 1982, 43, 605. 18 R. Lindahl, PhD Thesis, Umea° University and National Institute exposed to both formaldehyde and ozone. for Working Life, Umea°, Sweden, 1997. These results prove that MNBDH can be used to collect 19 CEN, European Committee for Standardization, EN 838, formaldehyde on diVusive filters in the same way as DNPH. Workplace Atmospheres—DiVusive Samplers for the Determination This is especially advantageous when formaldehyde has to be of Gases and Vapours—Requirements and Test Methods, CEN, determined in matrices that also contain oxidizing substances. Brussels, 1995. Besides, the determination using MNBDH as derivatization 20 J. O. Levin, K. Andersson, R. Lindahl and C. A. Nilsson, Anal. Chem., 1985, 57, 1032. reagent is much more selective, because the absorption maxi- 21 CEN, European Committee for Standardization, EN 482, mum of formaldehyde MNBDhydrazone is located at longer Workplace Atmospheres—General Requirements for the wavelengths compared with the DNPH derivative (474 nm Performance of Procedures for the Measurement of Chemical compared with formaldehyde DNPhydrazone at 349 nm). Agents, CEN, Brussels, 1994. Formaldehyde can be collected and determined in matrices containing ozone and nitrogen dioxide with reduced inter- Paper 8/07631F J. Environ. Monit., 1999, 1, 39

ISSN:0960-7919    

DOI:10.1039/a807631f

出版商:RSC    

年代:1999

数据来源: RSC

摘要:

Evaluation of two adsorbents for diVusive sampling and thermal desorption-gas chromatographic analysis of monoterpenes in air Anna-Lena Sunesson,*a Margit Sundgren,a Jan-Olof Levin,ab Ka°re Erikssonb and Rolf Carlsonc aDepartment of Chemistry, National Institute for Working Life, P.O. Box 7654, S-907 13 Umea° , Sweden. E-mail: Anna-Lena.Sunesson@niwl.se bDepartment of Occupational and Environmental Medicine, Umea° University, S-901 85 Umea° , Sweden cFaculty of Science, Department of Chemistry, University of Tromsø, N-9037 Tromsø, Norway Received 1st October 1998, Accepted 6th November 1998 Tube type samplers with two diVerent adsorbents, Chromosorb 106 and Tenax TA, were evaluated by laboratory experiments and field tests for simultaneous diVusive sampling of a-pinene, b-pinene and D3-carene and subsequent thermal desorption–gas chromatographic analysis.No statistically significant eVects of exposure time, concentrations of monoterpenes or relative humidity were found for samplers with Chromosorb 106 when running a factorial design, with the exception of the adsorption of D3-carene, for which some weak eVects were noted. Samplers with Tenax TA were aVected by the sampling time as well as the concentration for all terpenes, with a strong interaction eVect between these two factors.The terpenes showed good storage stability on both adsorbents. No eVect of back-diVusion was noted when using Chromosorb 106, while Tenax TA showed some back-diVusion eVects. The uptake rates, in ml min-1, for the terpenes on Chromosorb 106 were 0.36 for a-pinene, 0.36 for b-pinene and 0.40 for D3-carene.The corresponding average values on Tenax TA were 0.30 for a-pinene, 0.32 for b-pinene and 0.38 for D3-carene. The field validation proved that diVusive sampling on Chromosorb 106 agreed well with pumped sampling on charcoal for stationary samples, while the personal samples indicated a discrepancy of 25% between Chromosorb 106 and charcoal samples.Tenax TA generally gave lower results than Chromosorb 106 in all field samples. Samplers packed with Chromosorb 106 could be used to monitor terpene levels in workplaces such as sawmills. The major advantages with this method are the sampling procedure, which is simple to perform compared to other techniques, the easily automated analysis procedure and the possibility to reuse the samplers.using diVusive sampling correlated well with the obtained Introduction results by pumped sampling. Anasorb 727, a cross-linked DiVusive sampling of compounds in workplace air is a con- polystyrene, was the recommended adsorbent. The terpenes venient method of performing occupational exposure measure- were desorbed by solvent desorption from all samplers in these ments.1 Depending on the substances to be determined, the studies.To simplify the sampling and analysis procedure, and samplers contain various solid sorbents or reagent-coated to be able to reuse the samplers and thereby lower the analysis sorbents for the sampling of reactive compounds (chemosorp- costs, it was of interest to study a diVusive sampler constructed tion).2 DiVusive sampling is based on the gaseous diVusion of for thermal desorption analysis.substances from the atmosphere to the sorbent. The uptake The diVusive samplers used in this study are tube type on the sorbent is related to the concentration of the compounds samplers (Perkin-Elmer tubes). The sampled compounds are in the surrounding atmosphere. The diVusive uptake rate, that thermally desorbed and analysed by gas chromatography.The is the rate at which the diVusive sampler collects a particular sorbents studied are Tenax TA and Chromosorb 106. Tenax, gas or vapour from the atmosphere, is aVected by several a porous polymer consisting of 2,6-diphenyl-p-phenyleneoxide, factors. The geometry of the sampling device and the nature first described by van Wijk in 1970,6 is the most commonly of the sorbent and the sampled compound(s) are essential used adsorbent for thermal desorption.It has low blank levels, factors. The uptake rate can also be aVected by factors such high thermal stability, low water adsorption and is applicable as the concentration of the analyte, sampling time, temperato a wide range of compounds.7–11 It has been used for pumped ture, humidity and air velocity. The influence of these factors sampling of monoterpenes in forest air.12 However, it is not can be studied in laboratory tests.3 However, before using the suitable for very volatile or very polar compounds, because of samplers in the field, it is also important to perform field its low capacity for these compounds.8,13 In a European validations, since the work environment is more complex than Community (EC) project for the evaluation of potentially the atmospheres generated under controlled conditions in the useful sorbents for pumped sampling and measurement of laboratory.The levels of the compounds of interest may vary volatile organic compounds in workplace air, 20 compounds and the presence of other species may influence the uptake of of varying volatility and polarity were used as test compounds.the compounds of interest. Of the 16 adsorbents evaluated, Chromosorb 106, a cross- DiVusive sampling of monoterpenes in workplace air has linked polystyrene, was the adsorbent found to be feasible for been performed in some studies.4,5 The samplers used in these most compounds.It was therefore recommended for sampling studies were of two diVerent geometric designs and contained the more volatile and polar organic vapours encountered in diVerent solid sorbents. They were validated in laboratory tests as well as in field tests, and the results obtained when workplace air.14 However, several other adsorbents, including J. Environ. Monit., 1999, 1, 45–50 45Tenax TA, were suitable for the majority of the test CMA/100).A 5 or 10 ml or a 250 ml gas-tight syringe (Hamilton #1005, Hamilton #1010W and SGE 250R-GT) was compounds. used for the injection, depending on the concentration and The performance of the adsorbents for the simultaneous sampling time. The needle was connected to a fused silica diVusive sampling of a-pinene, b-pinene and D3-carene was capillary, which was inserted into a nebulizer (Meinhard evaluated according to slightly modified standard procedures.3 nebulizer TR-30-A7, J.E.Meinhard Associates). The air flow These monoterpenes are the main constituents of the sawing rate through the nebulizer was 0.9 l min-1. The aerosol from fumes released during the sawing and handling of pine (Pinus the nebulizer was mixed with air (5 l min-1) and evaporated sylvestris).These compounds can cause allergic and noninto an evaporation chamber. The evaporation chamber was allergic contact dermatitis,15–18 and are suspected of causing a heated to 30 °C to improve the vaporization of the terpene decrease in lung function among exposed workers.19 The mixture.The air mixture was further diluted and transported present limit value in Sweden is 150 mg m-3, for individual as to an exposure chamber made of Teflon, 900×80×60 mm3, well as total terpenes, a limit which is often exceeded.4,5,18,20 with 14 outlets for sampling. The total air flow through the For this reason, and as part of a company’s internal control exposure chamber was 40 l min-1, giving a wind velocity of programme, it is necessary to perform exposure assessment 0.3 m s-1 through the chamber.The air was controlled with among workers exposed to sawing fumes. respect to relative humidity by passing clean air through one DiVusive sampling is a user-friendly sampling technique, to four gas-dispersion bottles.22 which opens up the possibility for use in self-assessment, where the workers perform their own measurements.21 Its combi- EVects of concentration, sampling time and relative humidity nation with thermal desorption gives a low detection limit and makes it possible to reuse the samplers, which lowers the The terpene concentration, sampling time and relative analysis costs.The aim of this study was to find an adsorbent humidity (RH) of the sampling atmosphere were varied using suitable for diVusive sampling and subsequent thermal desorp- a factorial design. DiVusive samplers were exposed to the tion of monoterpenes in sawing fumes.various atmospheres by inserting the tubes in the outlets of the sampling chamber. The tubes were equipped with diVusion caps without membranes (Perkin-Elmer) during sampling.Experimental Four tubes packed with Tenax TA and four tubes packed with Chemicals and adsorbents Chromosorb 106 were simultaneously exposed for each experimental setting. On every sampling occasion, pumped samples The chemicals used for the dynamic generation of test atmoswere taken on six charcoal tubes to use as a reference method, pheres and for standards were (±)-a-pinene (Aldrich, 99%), employing a GAST model MOA-P101-CD pump.(1S)-(-)-b-pinene (Aldrich, 98%) and (+)-D3-carene (Fluka, 99%). Methanol (Merck, p.a.) was used for standards for Back-diVusion thermal desorption analyses. Carbon disulfide (Baker, p.a.) was used for desorption of charcoal tubes. The adsorbents DiVusive samplers were exposed in two sets of six replicates evaluated were Tenax TA, 60–80 mesh (Chrompack), and to a terpene mixture of 300 mg m-3 and 80% RH for 30 min.Chromosorb 106, 60–80 mesh (Perkin-Elmer). After 30 min, six tubes were capped with Swagelok caps and the other set was exposed to air at 80% RH free from terpenes DiVusive samplers for a further 7.5 h. The adsorbents were packed into stainless-steel tubes, 90 Capping eYciency mm×6.3 mm od×5.0 mm id (Perkin-Elmer).Approximately 60 mm of sorbent was packed in the tubes, and the tubes were To ensure that the Swagelok caps were completely tight, six conditioned overnight at 300 °C for Tenax TA and 250 °C for diVusive samplers were capped with Swagelok caps with PTFE Chromosorb 106. The tubes were sealed with Swagelok fittings ferrules at both ends, one end capped hand-tight and one with PTFE inserts.During sampling, the tubes were equipped using keys. The tubes were placed in a terpene atmosphere of with Perkin-Elmer diVusion caps. 300 mg m-3 and 80% RH for 8 h. Reference method Storage As a reference method, pumped sampling on charcoal tubes Twelve tubes of each adsorbent were exposed to a terpene (SKC, Cat No 226–01) was used. The sampling flow rate was mixture of 300 mg m-3 and 80% RH for 8 h.Six samplers about 100 ml min-1 for all tests. The tubes were desorbed in were analysed immediately after exposure. The others were 3 ml of carbon disulfide. capped and stored for 14 days at room temperature before analysis. Generation of terpenes Sample analysis Standard atmospheres of the three terpenes, in a mixture with a ratio of 105155 of a-pinene5b-pinene5D3-carene, were The diVusive samples were analysed by thermal desorptiondynamically generated according to Fig. 1. The terpene mixture gas chromatography. The samples taken by diVusive sampling was slowly injected into a stream of humidified air by means were desorbed in an automatic thermal desorption injector of a motor-driven microinjection pump (Carnegie Medicin (ATD 400, Perkin-Elmer), and the thermal desorption injection was run as follows.The tubes were desorbed at 220 °C for 10 min with a desorption flow of 30 ml min-1. Helium was used as carrier gas and the pressure on the injector and column was 30 psi. The temperature of the valve of the ATD 400 and of the line between the injector and the gas chromatograph was 200 °C.The cold trap was packed with Tenax TA (Chrompack, 60–80 mesh) and silanized glass wool (Supelco). The cold trap was kept at -30 °C during tube desorption, and the sample was thereafter desorbed from the cold trap by heating it to 250 °C for 5 min. No inlet split was used and the Fig. 1 Equipment for the dynamic generation of terpene standard atmospheres. outlet split was 70 ml min-1.The gas chromatographic separa- 46 J. Environ. Monit., 1999, 1, 45–50tions were performed on a Perkin-Elmer Autosystem XL gas relative to the calculated terpene concentrations given by the chromatograph with a fused silica column (HP Ultra 2, amount of injected terpenes and the air flow through the 50 m×0.2 mm id, coated with cross-linked 5% phenylmethyl- sampling chamber.These theoretical concentrations were consilicone, 0.33 mm). The flame ionization detector was kept at firmed by the analysed concentrations obtained by the refer- 250 °C. The temperature programme for the separations was ence method. The relative standard deviations (RSDs) of the 120 °C for 1 min, followed by a temperature rise of 10 °Cmin-1 amounts obtained in the thermal desorption analyses, between up to 200 °C, followed by a temperature rise of 20 °Cmin-1 tubes packed with the same adsorbent and exposed simulup to a final temperature of 240 °C, which was maintained for taneously in a given atmosphere, were generally 3–6%.The 1 min. The data from the analyses were recorded, integrated RSDs within a sampling set were at the same levels independent and quantified by a Perkin-Elmer Turbochrom Workstation of the experimental settings or the adsorbent used. 6.0.2.1. The significance of the various parameters was evaluated Reference standards for the quantification of the samples using multivariate methods as follows. Let y1, y2 and y3 be analysed by thermal desorption–gas chromatography were the observed responses for a-pinene, b-pinene and D3-carene.obtained by injecting the terpene mixture in various concen- Let x1, x2 and x3 be the scaled and centred settings of the trations in methanol onto tubes packed with Tenax TA. The experimental variables flow rate (x1), concentration (x2) and tubes were placed in a stream of helium (100 ml min-1) and relative humidity (x3), such that the high and low levels of the 1.0 ml of the standard solution was applied at the stainless- settings correspond to xi=+1 and -1, respectively.steel gauze in the tube. Helium was blown through the tubes The influence of the experimental factors was analysed by for 1 min in order to transfer the substances to the adsorbent the following procedure. The experimental data summarized and for removal of most of the solvent.The standards were in Table 1 were split into two parts: data recorded with analysed under the same conditions as the samples. Chromosorb 106 and data recorded with Tenax TA. These The desorbed reference samples taken on charcoal were data sets were analysed separately to assess the possible injected by split injection using an HP 7376 autoinjector; 1 ml influence of the settings of the experimental factors on the was injected with a split of 15100 onto an HP 5890 gas observed variations of the responses.chromatograph with a fused silica column (HP-1, To obtain a rough, preliminary indication of whether or not 12 m×0.2 mm id, coated with cross-linked methylsilicone, there was any strong correlation between the experimental 0.33 mm) and a flame ionization detector kept at 250 °C.The data (x-block) and the responses ( y-block), partial least injector temperature was 200 °C and the pressure on the squares in latent variables (PLS) models were fitted to the column was 10 psi. The temperature programme for the separadata. 23,24 The x-block was expanded by including the cross- tions was 35 °C for 2 min, followed by a temperature rise of product variables.This was performed to account for possible 3 °Cmin-1 up to 53 °C, followed by a temperature rise of interaction eVects of the experimental variables. Projections 30 °Cmin-1 up to a final temperature of 250 °C. The data onto two PLS components (the second was not significant) from the analyses were recorded, integrated and quantified by showed weak correlation between the experimental variables aWaters MillenniumA Chromatography Manager.All samples and the responses for the Chromosorb 106 data, and a taken for 240 min or more were diluted with carbon disulfide somewhat higher correlation for the Tenax TA data. For the before injection to avoid overloading the column. Samples Tenax TA data, the variables x1 and x2 and the cross-product taken for 480 min from an atmosphere of 15 mg m-3 were x1x2 were negatively correlated to the responses. diluted 1515, samples taken for 240 min at 150 mg m-3 were The next step in the analysis was to establish separate diluted 1535 and samples taken for 480 min at 300 mg m-3 response surface models including linear terms and two- were diluted 1575.variable cross-product terms for each response, yi.This aVorded estimates of the relative importance of each variable Field validation in the model. However, plots of the residuals, e= The samplers packed with the two adsorbents were evaluated yObserved-yPredicted vs. yPredicted showed the experiments at the in a sawmill where pine was sawn. Pumped sampling on centre point to have unacceptably large residuals, which indi- charcoal tubes, as described above, was used as a reference cated curved response surfaces.By deletion of insignificant method and was performed in parallel with the diVusive interaction terms from the models and inclusion of a square sampling. Personal and stationary sampling were carried out. term in x22, the models aVorded acceptable plots of the Samples were taken on two occasions.For personal sampling, residuals vs. the predicted response and also linear cumulative three diVusive samplers packed with Tenax TA and three normal probability plots of the residuals. Even though the packed with Chromosorb 106 were carried by each person, square term did not have a statistically significant influence in together with two charcoal tubes.The sampling was performed the variation of the observed responses, it improved the for a whole working day (about 8 h). SKC pocket pumps residual pattern. For this reason, it was kept in the models. 210–1002 were used for pumped sampling. The static sampling Interpretation of the models yielded the following conclusions. was performed at three diVerent places in the sawmill, chosen The variation of the relative humidity, x3, did not have any to expose the samplers to terpene levels ranging from low to influence on the variation in the observed responses for either above the limit value.Six diVusive samplers packed with Tenax of the two adsorbents. When using Chromosorb 106 as an TA and six with Chromosorb 106 were used, together with six adsorbent, none of the experimental variables exerted any charcoal tubes, at each place.The air flows through the significant influence (P>0.10) on the adsorption of a-pinene charcoal tubes for personal or stationary sampling were measand b-pinene. For the adsorption of D3-carene, there were ured before and after exposure using a rotameter (ROTA L0,25/14–5910). All workers changed work task every half weak but significant influences of x1 (P=0.015) and x2 (P= hour according to a working rotation scheme.Some work 0.03). For Tenax TA, both x1 and x2 had a significant influence tasks were performed in well-ventilated cabins, while other on the adsorption of all three compounds. For x1, P=0.004 tasks involved work close to the wood. (a-pinene), P=0.005 (b-pinene) and P=0.019 (D3-carene).For x2, P=0.004 (a-pinene), P=0.005 (b-pinene) and P=0.012 (D3-carene). For b-pinene also the interaction x1x2 exerted a Results and discussion significant influence on the adsorption, P=0.032. The follow- EVects of concentration, sampling time and relative humidity ing models were established. For D3-carene on Chromosorb 106, y3=0.372–0.035x1-0.024x2-0.0005x3+0.031x22+ The results obtained from the tests according to the factorial design are shown in Table 1.The uptake rates are determined 0.015x1x2-0.010x2x3. The established models on Tenax J. Environ. Monit., 1999, 1, 45–50 47Table 1 EVects of terpene concentration, sampling time and relative humidity of the sampling atmosphere on the calculated uptake rates Concentration/ Sampling time/ a-Pinene b-Pinene D3-Carene mg m-3 min RH(%) uptake rate uptake rate uptake rate Chromosorb 106 15 480 20 0.39 0.40 0.41 15 480 80 0.32 0.35 0.39 15 30 20 0.39 0.34 0.46 15 30 80 0.42 0.37 0.50 150 240 50 0.35 0.38 0.38 300 30 20 0.37 0.36 0.38 300 30 80 0.37 0.36 0.38 300 480 20 0.34 0.35 0.37 300 480 80 0.32 0.33 0.35 Mean value 0.36 0.36 0.40 RSD% 9.3 5.9 12 Tenax TA 15 480 20 0.32 0.35 0.39 15 480 80 0.29 0.32 0.36 15 30 20 0.34 0.34 0.45 15 30 80 0.37 0.38 0.45 150 240 50 0.28 0.32 0.36 300 30 20 0.34 0.35 0.38 300 30 80 0.35 0.37 0.41 300 480 20 0.22 0.24 0.30 300 480 80 0.22 0.23 0.29 Mean value 0.30 0.32 0.38 RSD% 18 17 15 TA were y1=0.0272–0.024x1-0.044x2-0.0016x3+0.035x22- of the terpene levels received on charcoal, while the average results on Tenax TA were 60% compared with charcoal. 0.020x1x2-0.08x2x3, y2=0.310–0.024x1-0.039x2-0.0036x3+ 0.012x22-0.026x1x2-0.012x2x3 and y3=0.371–0.033x1- The diVusive sampler used is a tube type sampler with a relatively small inlet (cross-sectional area, 0.2 cm2) and a 0.042x2-0.000037x3+0.006x22-0.006x1x2-0.008x2x3. comparably long diVusion gap (1.5 cm). One suspected reason for the discrepancy between the pumped and diVusive samplers Back-diVusion in the field validation was that this construction of the diVusive The results obtained from the back-diVusion tests are presented samplers might have some limitations in the ability to respond in Table 2.The results on Tenax TA were decreased by 0–25% to the rapidly changing atmospheres to which the workers are for the various terpenes when the samplers were exposed to exposed.Such eVects have been noted previously for various terpene-free air for 7.5 h, while no eVect of back-diVusion diVusive sampler designs, particularly when short concentrated could be seen for Chromosorb 106. pulses occur.25 The levels of terpenes in the sawmill can vary from almost zero in the well-ventilated cabins to far above the Capping eYciency limit value in other areas, and all workers change work task and also workplace within the sawmill every half hour.Another The capped samplers exposed to twice the limit value of explanation could be that the terpenes are partly particle terpenes for 8 h did not show any detectable amounts of bound. These particle-bound terpenes would be pumped onto terpenes.This shows that the Swagelok caps give an air-tight the charcoal tubes, but not adsorbed on the diVusive samplers seal to the tubes. to the same extent. However, such an eVect ought to be seen also on the stationary samples. Storage To elucidate whether or not the rapidly changing atmosphere The results from the storage test are presented in Table 3. The aVects the uptake on the diVusive samplers, a laboratory test recoveries remained stable on storage on both adsorbents.was performed where the exposure situation in the sawmill was simulated. The terpene levels were varied approximately Field validation as follows: 30 min 300 mg m-3-30 min 5 mg m-3-30 min 150 mg m-3-30 min 5 mg m-3-30 min 600 mg m-3-60 min The results from the field validation are presented in Table 4. 5 mgm-3-30 min 50 mg m-3-30 min 5 mg m-3-30 min The stationary samples on Chromosorb 106 generally corre- 300 mg m-3-30 min 5 mg m-3-30 min 50 mg m-3-30 min sponded well with the results obtained by pumped sampling 5 mgm-3-30 min 600 mg m-3-30 min 5 mg m-3. Pumped on charcoal, but the recoveries on Tenax TA were lower. All samples were taken on charcoal, and diVusive samples on personal samples taken by diVusive sampling were lower than the pumped samples.Chromosorb 106 gave, on average, 75% Perkin-Elmer tubes packed with Chromosorb 106 or Tenax Table 2 EVect of back-diVusion on the analysed amounts of terpenes. Conditions: concentration, 300 mg m-3; RH, 80%. The relative standard deviations, in percentages, within a series are given in parentheses; n=6 Adsorbent Time a-Pinene/mg b-Pinene/mg D3-Carene/mg Chromosorb 106 30 min 2.2 (2.3) 0.22 (2.9) 1.1 (2.6) Chromosorb 106 30 min+7.5 h 2.1 (2.3) 0.21 (2.4) 1.1 (2.9) Tenax TA 30 min 2.0 (1.3) 0.20 (1.4) 1.0 (1.0) Tenax TA 30 min+7.5 h 1.5 (1.5) 0.16 (1.6) 1.0 (0.9) 48 J.Environ. Monit., 1999, 1, 45–50Table 3 Analysed amounts of terpenes sampled at 300 mg m-3, terpene levels found on pumped personal samples.However, 480 min and RH 80% (top) and 15 mg m-3, 480 min and RH 20% the terpene levels in workplaces such as sawmills often vary (bottom), analysed directly after exposure (dir.) and after storage by factors of one or two orders of magnitude depending on (14 d). The relative standard deviations, in percentages, within a series the work task, etc.The simplicity of sampling and analysis are given in parentheses; n=6, unless otherwise specified using the samplers validated in this study, combined with the Adsorbent a-Pinene/mg b-Pinene/mg D3-Carene/mg advantage of being able to reuse the samplers, still make them an attractive method for monitoring terpene atmospheres in Chromosorb 106, dir. 30 (0.6) 3.1 (0.6) 16 (0.4) workplaces.The uncertainty of the method for personal sam- Chromosorb 106, 14 d 28 (3.0) 2.9 (4.5) 15 (3.4) pling must, however, be borne in mind when evaluating the Tenax TA, dir. 19 (1.2) 2.0 (1.4) 13 (1.0) exposure data. Tenax TA, 14 d 18 (1.0) 1.9 (2.2) 12 (1.2) Standards for thermal desorption Chromosorb 106, dir. 1.6 (1.0) 0.14 (1.5) 0.78 (1.0) Chromosorb 106, 14 da 1.6 (4.3) 0.14 (7.2) 0.82 (5.2) Reference values for the thermal desorption analyses were Tenax TA, dir. 1.2 (1.3) 0.12 (3.1) 0.72 (2.9) obtained by injecting terpene standards in methanol onto Tenax TA, 14 d 1.2 (1.3) 0.13 (1.2) 0.76 (1.7) tubes packed with Tenax TA, whereupon helium was blown an=3. through the tubes at 100 ml min-1 for 1 min. Several attempts to prepare standards on Chromosorb 106 according to the same procedure as for Tenax TA were made, but it was not Table 4 Measured air concentrations, in mg m-3, of terpenes in the possible to obtain reproducible results and standard values sawmill using diVerent sampling techniques and/or adsorbents.Pumped samples were taken on charcoal, diVusive samples on comparable with the standards on Tenax TA. The amounts Chromosorb 106 and Tenax TA, sampling time approximately 8 h.obtained on Chromosorb 106 were considerably lower, and Stationary samples, n=6 for all samplers; personal samples, n=2 for the ratios between the various terpenes were not as expected. the charcoal samplers, n=3 for the diVusive samplers. The relative In addition to methanol as a solvent for the terpene standards, standard deviations, in percentages, within a series are given in hexane, ethyl acetate, dichloromethane and acetone were tried parentheses as alternatives, but none of them gave reproducible results Sampling corresponding to the expected levels of terpenes. The time for place/ blowing helium through the samplers after injection of the person Charcoal Chromosorb 106 Tenax TA standards was varied between 1 and 20 min, but prolonging this blow time did not improve the standard recoveries. Stationary samples Standards were made on Chromosorb 106 by pumping a 1 1.4×102 (5.4) 1.3×102 (3.6) 1.0×102 (5.6) dynamically generated atmosphere through the tubes, using 2 37 (1.8) 48 (4.3) 41 (10) 3 5.0×102 (8.0) 4.3×102 (8.9) 3.2×102 (9.9) the same procedure as for the reference method on charcoal. 4 54 (8.6) 37 (24) 35 (5.5) The results obtained by analysing these standards were equival- 5 2.5×102 (7.0) 2.9×102 (5.4) 2.1×102 (1.1) ent to the values obtained using methanol standards on 6 6.2 (0.04) 5.8 (4.0) 6.4 (2.7) Tenax TA. Personal samples 1 97 (2.2) 62 (4.2) 55 (4.5) Conclusions 2 47 (6.0) 31 (8.1) 27 (5.8) This study proves that Chromosorb 106 is a better adsorbent 3 86 (1.1) 67 (7.5) 49 (5.2) 4 65 (4.6) 44 (6.2) 35 (7.0) for the diVusive sampling of monoterpenes than Tenax TA. 5 80 (15) 62 (4.8) 51 (1.2) While Tenax TA is aVected by terpene concentration as well 6 36 (0.7) 25 (5.5) 20 (2.8) as sampling time, Chromosorb 106 is unaVected by all variables 7 39 (0.9) 32 (10) 24 (1.3) included in this evaluation for a-pinene and b-pinene, and the 8 46 (2.7) 37 (2.1) 30 (2.4) eVects of concentration and sampling time on the adsorption 9 72 (4.9) 71 (11) 47 (2.2) of D3-carene found in the multivariate data analysis are weak. 10 39 (1.8) 27 (1.6) 22 (0) The eVect of back-diVusion on Chromosorb 106 is negligible, while Tenax TA showed reduced terpene levels in the back- TA.Four diVusive samplers of another geometry, SKC model diVusion test, representing a worst-case situation of a non- 575, which have given good agreement with pumped samples constant atmosphere.Both adsorbents show good storage on charcoal in the field sampling of terpenes in a previous stability. study,19 were also exposed to this fluctuating atmosphere. The The uptake rates, in ml min-1, for the terpenes on analysed average terpene levels on the samplers were as Chromosorb 106 were 0.36 for a-pinene, 0.36 for b-pinene follows, with the average RSDs in percentages given in par- and 0.40 for D3-carene.The corresponding values on Tenax entheses after the levels: charcoal (pumped) 119 mg m-3 TA were 0.30 for a-pinene, 0.32 for b-pinene and 0.38 for D3- (1.2%), Chromosorb 106 117 mg m-3 (1.5%), Tenax TA carene.However, since the uptake rate on Tenax TA is aVected 94 mg m-3 (1.9%) and SKC 575 100 mg m-3 (4.2%). The by the concentration of the atmosphere as well as the sampling agreement between the pumped samples on charcoal and the time, it is not suitable to use an average uptake rate when diVusive samples on Chromosorb 106 is excellent, and the calculating the concentration of the sampled atmosphere when construction of the diVusive sampler is therefore not likely to sampling on this adsorbent.If Tenax TA is used as adsorbent, cause the discrepancy found in the field validations. it is necessary to adjust the uptake rate to the sampled amount, The 25% discrepancy between the diVusive samples on taking the sampling time as well as the concentration into Chromosorb 106 and pumped samples on charcoal in the field consideration.validation is not yet fully understood. One theory is that The diYculties in preparing standards on Chromosorb 106 terpene-containing particles could be stuck on clothes in by tube spiking using a standard solution in methanol or other atmospheres with high terpene levels. On moving, some of solvents makes it necessary to dynamically generate the stanthese particles would be released, which could cause increased dard atmospheres needed.An alternative is to use Tenax TA levels of terpene-containing particles around the person. Such for the standards. particles would be caught by pumped sampling, but not The field validation proved that the terpene uptake on stationary diVusive samplers packed with Chromosorb 106 diVusive sampling, and could possibly explain the higher J.Environ. Monit., 1999, 1, 45–50 495 K. Eriksson, J. O. Levin, M. Rhe�n and R. Lindahl, Analyst, 1994, agreed well with the terpene levels measured by pumped 119, 85. sampling on charcoal, while stationary diVusive sampling on 6 R. van Wijk, J. Chromatogr. Sci., 1970, 8, 418. Tenax TA generally gave a lower result.However, all personal 7 J. Jana�k, J. Ruzickova� and J. Nova�k, J. Chromatogr., 1974, 99, samples taken by diVusive sampling gave lower results than 689. the pumped samples. This was suspected to be caused possibly 8 R. H. Brown and C. J. Purnell, J. Chromatogr., 1979, 178, 79. 9 G. MacLeod and J. M. Ames, J. Chromatogr., 1986, 355, 393. by the construction of the diVusive sampler.The Perkin-Elmer 10 K. Kawata and I. Kifune, Eisei Kagaku, 1991, 37, 281. tube type diVusive sampler is constructed with a comparatively 11 M. de Bortoli, H. Kno�ppel, E. Pecchio, H. Schauenburg and H. small cross-sectional area and a large diVusion gap.26 It was Vissers, Indoor Air, 1992, 2, 216. considered possible that this construction may have some 12 R.J. B. Peters, A. D. V. Renesse and V. Duivenbode, Atmospheric limitations when used in rapidly changing atmospheric concen- Environment, 1994, 28, 2413. trations, since the results obtained by diVusive sampling were 13 J. H. Glover, Thermal Desorption in Industrial Hygiene and Environmental Analysis, Spantech Publishers, New Delhi, 1991. lower for personal samples in the field validation compared 14 R.H. Brown, Analyst, 1996, 121, 1171. with pumped samples. However, when the exposure situation 15 W. Grimm and H. Gries, in Encyclopaedia of Occupational Safety of a rapidly changing atmospheric concentration for the andd. L. Parmeggiani, International Labour Organi- workers in the sawmill was simulated in a laboratory test, no zation, Geneva, 1983, p. 2229. discrepancy between pumped sampling on charcoal and diVus- 16 S. Hellerstro�m, Acta Derm. Vener., 1939, 20, 657. ive sampling on Perkin-Elmer tubes packed with Chromosorb 17 V. Pirila� and E. Siltanen, Dermatologia, 1958, 117, 1. 18 K. Eriksson, Occupational Exposure to Terpenes in Saw Mills and 106 was found. We believe that this eVect of higher levels from Joinery Shops, PhD Thesis, University of Umea°, 1996. the charcoal tubes in the field validation is caused by wood 19 G. Hedenstierna, R. Alexandersson, K. Wimander and G. Rose�n, particles released from the workers’ clothes, resulting in particle Int. Arch. Occup. Environ. Health, 1983, 51, 191. sampling on the charcoal tubes and terpene release from these 20 K. Eriksson and J. O. Levin, Int. Arch. Occup. Environ. Health, particles. This will be investigated further. 1990, 62, 479. 21 I. Andersson, A. Stro�mba�ck, B. Ja�rvholm, J. O. Levin, B. Strangert and A.-L. Sunesson, Appl. Occup. Environ. Hyg., References submitted. 22 J.-O. Levin, R. Lindahl and K. Andersson, Environ. Sci. Technol., 1 DiVusive Sampling. An Alternative Approach to Workplace Air 1986, 20, 1273. Monitoring, ed. A. Berlin, R. H. Brown and K. J. Saunders, Royal 23 H. Wold, in Systems Under Indirect Observations, ed. K.-G. Society of Chemistry, London, 1987. Jo�reskog and H. Wold, North Holland, Amsterdam, 1982, vols. I, 2 J. O. Levin, in Clean Air at Work—New Trends in Assessment and II, ch. 1. Measurements for the 1990s, ed. R. H. Brown, M. Curtis, 24 R. Carlson, Design and Optimization in Organic Synthesis, K. J. Saunders and S. Vandendrische, Royal Society of Chemistry, Elsevier, Amsterdam, 1992, pp. 462–492. Cambridge, 1992, p. 135. 25 D. L. Bartley, G. J. Deye and M. L. Woebkenberg, Appl. Ind. 3 Workplace Atmospheres—DiVusive Samplers for the Determination Hyg., 1987, 2, 119. of Gases and Vapours—Requirements and Test Methods, EN 26 R. H. Brown, J. Charlton and K. J. Saunders, Am. Ind. Hyg. 83851995, Comite� Europee�n de Normalisation, Brussels, 1995. Assoc. J., 1981, 42, 865. 4 K. Eriksson and J. O. Levin, Chemosphere, 1995, 30, 1541. Paper 8/07657J 50 J. Environ. Monit., 19

ISSN:0960-7919    

DOI:10.1039/a807657j

出版商:RSC    

年代:1999

数据来源: RSC