摘要:

RSC ANALYTICAL DIVISION ELECTROANALYTICAL GROUP and SOUTH EAST REGION A Joint Meeting on RECENT DEVELOPMENTS IN WATER ANALYSIS will be held at the CEGB, Canal Road, Gravesend Wednesday, June 6th, 1984 The lectures given at this meeting will be: "Power Station Water Analysis," by K. Wall (CEGB, Gravesend); "Adsorption Enhanced Polarography for Some Transition Metal Ions," by K. Torrance (CERL, Leatherhead); "Dionex Ion-exchange Chromatographic Water Analysis at Trace Levels," by D. Smith (CEGB, Gravesend); "Modern Trends in Continuous Water Quality Monitoring," by R. Barnhoorn (Eastbourne Water Co.); "Problems in pH Measurement in Fresh Water," by P. D. Whalley (Newcastle University); and "Recent Studies on the Measurement of Iron and Aluminium in Potable Water," by P.Watson (Kent Industrial Measurements Ltd., Chertsey). The registration fee will be f10 for RSC members, f12 for non-members and f5 for bona fide students. Lunch and refreshments are provided. Those wishing to attend should write immediately to Mr. A. E. Bottom, Kent Industrial Measurements Limited, Oldends Lane, Stonehouse, Gloucestershire, GL10 3TA. CHALLENGES TO CONTEMPORARY DAIRY ANALYTICAL TECHNIQUES I mm' Softcover 350pp 0 85186 925 4 Price f 16.00 ($29.00) RSC Members f12.00 Special Publication No. 49 Over many years international organizations, national organization and private concerns have prepared standardized methods on analysis for food products, including milk and milk products, for purposes of quality control, assessment of nutritive content, enforcement of legal requirements and affirmation of safety.This activity is concerned with identifying the most appropriate current methodology and codifying it in authoritative documents. The object of this book is to appraise the problems that will be faced by analysts of dairy products in the future and examine the means that are likely to be used to solve them. Brief Contents: Collaborative Studies and Reference Materials; Determination of Major Constituents: Automated, Instrumental Methods; Determination of Micro-constituents: Advanced Methods; Determination of Compounds Formed during Processing and Storage (Artefacts) and Contaminants. Non-RSC members should send their orders to: The Royal Society of Chemistry, Distribution Centre, Blackhorse Road, Letchworth, Herts SG76 IHN, England. RSC members should send their orders to: The Royal Society of Chemistry, Membership Office, 30 Russell Square, London WCIB 5DT.

ISSN:0144-557X    

DOI:10.1039/AP98421FX015

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年代:1984

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ANALYTICAL DIVISION DIARY May, 1984 Royal Society of Chemistry Analytical Division Atomic Spectroscopy Group SECOND BIENNIAL NATIONAL ATOMIC SPECTROSCOPY SYMPOSIUM July 10th-13th 1984 University of Leeds The scientific programme will be contained in five sessions, each session being led by a plenary lecture. After each plenary lecture the session will be split into two parallel streams each headed by a invited speaker and followed by contributed papers. The plenary lectures will be given by R. M. Barnes, J. 6. Dawson, D. E. Leyden, L. C. Ebdon and S. Greenfield, and the invited lecturers will be K. Laqua, M. Thompson, W. Frech, N. J. Goddard, H. W. M. Webster, H. T. Delves, J. Tyson, D. L. Miles, J. M. Mermet and K. Paul. For further information contact Mr.F. Buckley, Department of Earth Sciences, University of Leeds, Leeds, West Yorkshire, LS2 9JT. 193 Institute of Physics Spectroscopy Group SPECIAL ISSUE OF THE ANALYST MARCH 1984 The March 1984 issue of The Analyst contains 46 papers presented at SAC 83 - The 6th International Conference on Analytical Chemistry, held in Edinburgh, 17th-23rd July 1983. The papers presented cover the most important areas of analytical chemistry and provide a valuable overview of the conference. The March issue of The Analyst contains the 4 plenary lectures, as listed below, as well as 42 other papers presented. Plenary Lectures: Recent Developments in Fluorescence and Chemiluminescence Analysis - James N. Miller. Capillary Separation Methods: a Key to High Efficiency and Improved Detection Capabilities - Milos Novotny . Design and Application of Neutral Carrier-based Ion-selective Electrodes - W. Simon, E. Pretsch, W. E. Morf, D. Ammann, LJ. Oesch and 0. Dinten. Continuum Source Atomic-absorption Spectrometry: Past, Present and Future Prospects - Thomas C. O'Haver. Single Issue Price: RSC Members .330.00 ($18.50). Non-RSC Members $15.00 ($27.50). ORDERING: r v Non-RSC members should send their orders to: The Royal Society of Chemistry, Distribution Centre, Blackhorse Road, Letchworth. Herts SG6 1HN. Eneland. RSC Members should send their orders to: The Royal Society of Chemistry, Membership Officer, 30 Russell Square, London WClB 5DT. PAYMENT SHOULD ACCOMPANY ORDER. ~~~ ~~ Electronically typeset and printed by Heffers Printers Ltd, Cambridge, England

ISSN:0144-557X    

DOI:10.1039/AP98421BX017

出版商:RSC    

年代:1984

数据来源: RSC

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ANPRDI 21(5) 157-194 (1984) May 1984 Hon. Secretary R. Sawyer Analvtical Proceedinas Proceedings of the Analytical Division of The Royal Society of Chemistry AD President S. Greenfield Hon. Treasurer 0. C. M. Squirrel1 Hon. Assistant Secretary D. I. Coomber, O.B.E. Hon. Publicity Secretary Dr. J. F. Tyson, Department of chemistry, Loughborough University of Technology, Loughborough, Leicestershire, LE11 3TU Secretary Miss P. E. Hutchinson Editor, Analyst and Analytical Proceedings P. C. Weston Senior Assistant Editors Assistant Editor Mrs. J. Brew, R. A. Young Ms. D. Chevin ,Publication of Analytical Proceedings is the responsi- bility of the Analytical Editorial Board: J. M. Ottaway (Chairman) L. S. Bark G. J. Dickes L. C. Ebdon A. C. Moffat J. M. Skinner J. D. R. Thomas A.M., Ure *P. C. Weston *G. W. Kirby J. Whitehead *Ex officio members All editorial matter should be addressed to: The Editor, Analytical Proceedings, The Royal Society of Chemistry, Burlington House, Piccadilly, London, WIV OBN. Telephone 01-734 9864. Telex 268001. Advertisements: Advertising Department, The Royal Society of Chemistry, Burlington House, Piccadilly, London, WIV OBN. Telephone 01-734 9864. Analytical Proceedings (ISSN 0144-557x1 is published monthly by The Royal Society of Chemistry, Burlington House, London, WIV OBN, England. All orders, accompanied by payment, should be sent to The Royal Society of Chemistry, The Distribution Centre, Black- horse Road, Letchworth, Herts., SG6 IHN, England. 1984 Annual Subscription price if purchased on its own: UK f53.00, Rest of World f56.00, US $106.00, including air speeded delivery.Air freight and mailing in the USA by Publications Expediting Inc., 200 Meacham Avenue, Elmont, N.Y. 11003. USA Postmaster: Send address changes to: Analytical Proceedings, Publications Expediting Inc., 200 Meacham Avenue, Elmont, N.Y. 11003. Second class postage paid at Jamaica, N.Y. 11431. All other despatches outside the UK by Bulk Airmail within Europe, Accelerated Surface Post outside Europe. PRINTED IN THE UK. @The Royal Society of Chemistry, 1984. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form, or by any means, electronic, mechanical, photographic, recording, or otherwise, without the prior permission of the publishers. Analytical Division Dinner and Presentation of Awards The Biennial Formal Dinner of the Analytical Division was held in the Library of The Royal Society of Chemistry in Burlington House, London, on Friday, March 2nd.The dinner was preceded by the President’s Reception, which was held in the Council Room. Professor T. S. West (L) being received by the AD President, Professor S . Greenfield, and Mrs. Greenfield The guests at the dinner included Professor W. J. Albery of Imperial College of Science and Technology, Professor K. W. Bentley of Loughborough University of Technology, Professor R. 0. C. Norman of the University of York, President Elect of the Royal Society of Chemistry, and Mrs. Norman, Professor T. S. West of the Macaulay Institute for Soil Research (the Secretary General of IUPAC), Dr.A. J. Amos and Mrs. Amos. Professor R. 0. C. Norman (President Elect of the RSC) and Mrs. Norman being received by Professor and Mrs. Greenfield 157158 AD DISTINGUISHED SERVICE AWARD Anal. Proc., Vol. 21 and Analytical Science, University of Manchester Institute of Science and Technology, for his contributions to advances in atomic spectrometry inductively coupled plasma emission spectrometry and optoacoustic spectroscopy. An oration on Professor Kirkbright was delivered by Professor T. S. West, and the Medal was presented by the President. A biography of Professor Kirkbright appeared in the May 1983 issue of Analytical Proceedings (p. 195). Professor Greenfield next presented the ninth AD Distinguished Service Award to Dr. D. Simpson for her services over many years to the activities of the SAC and AD and also to the East Anglia Region and the Chromatography and Electrophoresis Group. A bio- graphy of Dr. Simpson appears below. The President’s Reception: (L-R) Professor W. J. Albery, Mrs. Greenfield, Professor Greenfield, ProfessorR. 0. C. Norman and Professor K. W. Bentley The Loyal Toast was proposed by the President, Professor S. Greenfield. Then followed the presenta- tion of the sixteenth SAC Gold Medal to Professor G. F. Kirkbright of the Department of Instrumentation Presentation of the ninth AD Distinguished Service A ward by the President to Dr. D. Simpson The toast of “The Analytical Division” was proposed by Professor Albery ; Professor Greenfield responded and also proposed the toast of “The Guests.” Professor Bentley responded on behalf of the guests. Presentation of the sixteenth SAC Gold Medal by the President to Professor G. F. Kirkbright

ISSN:0144-557X    

DOI:10.1039/AP9842100157

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年代:1984

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AD DISTINGUISHED SERVICE AWARD Analytical Division Distinguished Service Award 158 As was announced in the February issue of Analytical Proceedings (p. 79) the ninth Analytical Division Distinguished Service Award has been made to Dr. Diana Simpson. Dr. Simpson commenced work with the ICI Phar- maceutical Division in Manchester and after 8 years joined Pfizer Limited as Senior Analyst at the Folke- stone establishment. She left on marrying and moved to North East Essex where her husband was working. After some years of part-time teaching and lecturing she again took a full-time job this time in the plastics industry and became Head of Analytical Services at the Research and Development establishment of BXL. In 1975 with her husband she started Analysis For Industry an independent consultancy at Thorpe-le- Soken in Essex.Anal. Proc. Vol. 21 She did not study chemistry while at school (where she was told it was a subject not suitable for young ladies) but was always determined to become an analyst. Her Master of Philosophy and Doctorate were both awarded for studies on the analysis of additives in plastics materials. Dr. Simpson joined the Society for Analytical Chem- istry (as the Analytical Division used to be) 20 year ago; she has tried to play an active part in its affairs and has always enjoyed doing so. She was involved closely in the formation of the East Anglia Region and following its inauguration was Honorary Secretarynreasurer STANDARDISATION IN PARTICLE SIZING May 1984 From 1967 to 1975 Vice-chairman and then Chairman From 1977 to 1979.On leaving the committee last year she was somewhat overwhelmed to be presented with a andsome RSC paperweight which holds a place of honour in her office. 159 served on the AD Programmes Committee from 1976 to 1979 and subsequently on the Group Liaison and Policy Committee was a member of The Analyst Publications Committee (1978-1981) and is on The Analyst Advisory Board. For 2 years from 1980 Dr. Simpson was an ex oficio member of the Trust Advisory Committee and she served on the Analytical Methods Committee from 1980 to 1983. In 1976 she was elected for the first time to the Council of the Analytical Division on which she served until 1979 (and also from 1980 onwards).She has been for some years a Trustee and was a Vice-president of the Division from 1980 until 1982. She has played an active part also in the Essex Local Section (Honorary Secretary 1975-1978) and in other divisions of the RSC is Editor of the Eastern Region Newsletter of the Education Division and represents the Eastern England Region (on which she has served as both Honorary Secretary and Chairman) on the Council of the Industrial Division. She was last year elected to the Council of the Society. For some years Dr. Simpson has been a United Kingdom delegate to International Standards on Plas- tics (IS0 TC/61) which has taken her to Tokyo Ottawa Madrid Budapest Moscow and Orlando Florida among other places. Her hobbies include reading compiling and solving crosswords making herself proficient in computer programming and accom- panying her dog on its walks. In her spare time she is helping to organize the formation of a new Centre of the Institute of Directors. She enjoys work in her busy practice takes pride in helping to arrange successful scientific meetings and confesses a special fondness for her husband her menagerie (a Great Dane named Sophie and a tabby Siamese which answers to “Junket”-and to the rattle of a food bowl) and for (watching) cricket. Her association with the Chromatography and Elec- ophoresis Group has also been quite lengthy; she has been Honorary SecretaryRreasurer since 1967. She

ISSN:0144-557X    

DOI:10.1039/AP9842100158

出版商:RSC    

年代:1984

数据来源: RSC

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May, 1984 STANDARDISATION IN PARTICLE SIZING 159 Standardisation in Particle Sizing The following are summaries of four of the papers presented at a Meeting of the Particle Size Analysis Group held on September 28th, 1983, at the National Physical Laboratory, Teddington, Middlesex. Current and Future British Standards ;. W. Lines oulter Electronics Ltd., Luton, Bedfordshire In 1979 British Standards formed committee CPE 10/4 to review the existing methods for the Determination of Particle Size of Powders, B.S. 3406 Parts 1-4, and revise where necessary, and also to consider methods which have come into more widespread use since those parts were issued in 1961 and 1963. In addition to particle size analysis, they were also to consider updating the existing specific surface area standards (B.S.4359), which were produced around 1970. In the event, all of these standards were considered to be in need of revision, to a greater or lesser extent. The current position on these standards is as follows. 1.S. 3406 “Methods for the Determination of Particle Size of Powders.” B.S. 3406: Part 1: 1961; Sub-division of Gross Sample Down to 0.2 ml. Active project, commenced 1982. Target date for publication, late 1984. B.S. 3406: Part 2: 1963; Liquid Sedimentation Methods.160 STANDARDISATION IN PARTICLE SIZING Anal. Proc., Vol. 21 Split into two parts; Part 2, gravitational sedimentation, work completed, due for publication late 1983. The other part will be Part 6, centrifugal sedimentation; active project. Target date for publication mid-late 1984.B.S. 3406: Part 3: 1963; Air Elutriation Methods. No active project. These methods are felt to be no longer used. Considering its removal in B.S. 3406: Part 4: 1963; Optical Microscope Method. Commenced 1982. To be enlarged (or split) to cover electron microscopy. B.S. 3406: Part 5: 1983; Electrical Sensing Zone Method (the Coulter Principle). New Standard in the series. Published September 1983. B.S. 3406: Part 6; Liquid Sedimentation (Centrifugal). New Standard in the series. See B.S. 3406: 2 (above). B.S. 3406: Part 7; Light Scattering by Single Particles. Proposal for new Standard. Just accepted as a project by British Standards (September 1983). “Methods for the Determination of Specific Surface of Powders.” B.S. 4359: Part 1: 1969; Nitrogen Adsorption (B.E.T. Method).Active project. Target date for publication mid-1984. B.S. 4359: Part 2: 1971; Air Permeability Methods. Revision published February 1983. B.S. 4359: Part 3: 1970; Calculation from the Particle Size Distribution. No active project. Felt to be unsatisfactory as a method of specific area determination. 1987-8. B.S. 4359 Each of these standards or proposed standards should be considered in more detail. B.S. 4359: Part 1 (B.E. T.). This standard is still in the course of preparation. It has concentrated on two aspects, i.e., the re-design of the burette and the updating of the nomenclature. It is normal to quote the range of applicability of the B.E.T. equation in interpreting experimental data as lying between x = 0.05 and x = 0.35 but the region of fit should be found from the linear par1 of the plot of xlns(1 - x ) against x.It is therefore desirable to have the maximum number of equally spaced points lying inside this region of fit if the region is to be determined reliably and consistent values obtained between various determinations. The burette recommended in this specification was designed to achieve this objective and was the result of a computer simulation by Dr. M. J. Jaycock of Loughborough University. The updating of the terms used in this specification involved mainly the replacement of “volumes of gas” by “moles of gas” as the gas adsorbed cannot be visualised as having a volume. Needless to say, SI units have been used throughout. B. S. 4359: Part 2, Recommended Air Permeability Methods.This has been published. In contrast to the gas adsorption (B.E.T.) method, it uses the effective (not true) solid density for its calculations, thereby ignoring porosity. Consequently, the specific surface obtained from permeability measure- ments is properly called the “effective permeability volume specific surface,” denoted by s,. This gives a measure of the fineness of a powder, which is what is sometimes required. A technical change to the basic equation used to relate permeability data to specific surface area was made in this revision. The original standard was based on the Kozeny - Carman equation and referred the user to other publications for procedures to follow in the transitional zone between wholly viscous flow and flow due to molecular diffusion.(The extra component of flow in this transitional zone is known as slip flow). The revision is based on one of the equations that takes slip flow into account, and the Carman - Arnell equation has been chosen. For coarse powders, where the effect of slip flow is small, or for some industrial purposes where the value due to viscous flow alone is sufficient for quality control, that part of the Carman - Arnell equation giving the contribution of viscous flow is identical to the Kozeny - Carman equation. The methods given in Part 2 are applicable to powders with permeability volume specific surfaces in the range from 2 x 104 to 5 x 107 m2/m3 (0.2-50 m2/crn3). B. S. 4359: Part 3, Calculation. The calculation of surface area from the particle size distribution has not yet been considered.Although there is nothing mathematically wrong with, nor can revisions be suggested to, this standard, it is arguable that surface area should be measured and not estimated by means of a calculation from the particle size distribution. B.S. 3406: 1 (Sampling). This is providing a controversial subject for revision as everyone believes that he or she is an expert in sampling! So far, the draft revision concentrates on being a practical guide in the representative sub-division of the sample delivered to the laboratory (the laboratory sample) toMay, 1984 STANDARDISATION IN PARTICLE SIZING 161 the portion taken for analysis (the test portion), but includes guidelines on procedures for obtaining the gross and laboratory samples. ( a ) , the introduction of scoop sampling, chute riffling and additional rotary sampling methods; and ( b ) , the deletion of the halving, turntable-type, oscillating-hopper and grid-type methods.Methods for preparing small (<0.5 ml) test portions are included, for instance by suspension sampling, as well as additional comments on the preliminary examination of the sample and precautions to be considered. Clauses on the principles of sampling, sampling strategy and selection of sampling methods have been prepared and comparative sampling efficiency data has been presented. While whole stream rotary sampling is, in general, to be preferred for free flowing powders, with some materials the other less sophisticated methods, even coning and quartering, still have a considerable part to play.B.S. 3406: 2 (Gravitational Liquid Sedimentation). This is a revision of the old Liquid Sedimentation Standard. It gives the fixed position pipette incremental (Andreasen) method its rightful place as the prime standard technique because it gives the mass distribution directly. However, the flexibility of the variable position pipette may be preferred by some for routine applications. Sedimentation balance designs are included, but the old liquid column method with sediment extraction is dropped. Now added are the monitoring of the mass change during sedimentation by the use of both light and X-rays; these are fairly common current techniques allowing the automatic or semi-automatic accumulation of data and calculation and presentation of results.The use of X-rays is more direct, as the change of mass of materials above an atomic number of 13 is measured, whereas with light a correction for extinction coefficient is required or a value of unity arbitrarily accepted to allow comparative results. It is recommended that gravitational sedimentation is not extended below 1 pm; for the sub-micrometre size range, and somewhat above, centrifugal techniques should be used [B.S. 3406: Part 6 (in preparation)]. B.S. 3406: 4 (Optical Microscope). As I have indicated, this is being extended, or split into two parts, to cover both optical and electron microscopy, because the latter is slowly becoming more widely used €or the sub-micrometre size range as scanning electron microscopes, in particular, become more reasonably priced.It is probable that the work will be split, and optical microscopy retained as one standard. It will be more cautious in its recommendations than the original standard, particularly on small (<2 pm) particle measurement, as accuracy is poor at these levels. A significant change since 1963 is in the use of automated image analysis, or semi-automated (such as image shearing), techniques to reduce operator tedium and to allow faster accumulation of a wider variety of data from a specimen, which will be covered in the revised standard. B.S. 3406: 5 (Electrical Sensing Zone). This new standard introduces recommended methods for this widely used principle, as applied to powder size distribution analysis in the sub-sieve range. Because of the wide range of applications possible it is somewhat lengthy and resembles an instruction manual, being suitable in general for all relevant models based on the Coulter Principle.The primary calibration technique recommended is that of mass integration, which allows the method to be self-calibrating and to approach being absolute. That is, a known mass of a narrowish size range of the sample material under test is diluted to a known volume, and counted via an accurate manometer assembly, when the calibration constant can be determined after the “immersed density” of the particles is found. This compensates for any potential errors due to particle shape, porosity or conductivity, so that the electrolyte-displaced particle volume is subsequently measured. Latex calibration, i.e., referencing to a previously characterised standard, is an acceptable alternative method of calibration. Whichever method is selected, it should be stated on the report form. As an introduction, a simple response theory is briefly given to allow a basic understanding; however, it is realised that more complex theories now exist which do not predict an upper limit of size response at about 40% of the aperture diameter, in keeping with recent experimental data, which shows no significant error in volumetric response, at least for the spherically shaped particles employed and the latest model, even up to the diameter of the aperture itself. The Standard also lists suggested electrolyte solutions for some 200 of the more commonly found powdered materials. B.S.34065 (Centrifugal Sedimentation). This is a new standard, produced as an off-shoot of the Part 2 revision, suitable for the size range of about 0.05 to 5 or 10 pm. Concentration effects are noted, and the user is cautioned to use no more than 0.2% by volume of powder and to verify results by making a Differences between the proposed revision and the 1961 original include:162 STANDARDISATION IN PARTICLE SIZING Anal. Proc., Vol. 21 repeat analysis at half of that concentration. The techniques recommended and detailed are the X-ray centrifuge, the photocentrifuge, the fixed pipette centrifuge (as for instance the design of Dr. Allen) and the decantation centrifuge method (as used in the usual form of the Joyce - Loebl disc centrifuge). B.S. 3406: 7 (Single Particle Light Scattering Counters).This new Standard will be commenced shortly. It should be noted that another proposal, that for multiple scattering particle size analysers such as those using the laser diffraction technique, was rejected by British Standards as it was felt that the methods were not sufficiently advanced to justify consideration as a standard. Now that approval has been given for single particle optical counters, it will again raise the problem noted in the course of preparation of Part 5, namely limiting the Standard to sub-sieve powders. Many light scatter counters are used to monitor contamination, for instance in clean room air, where a standard would presumably be welcomed. The general title of B.S. 3406 is therefore not a good one. It prevents standardisation in many areas which we, as particle technologists, might wish to standardise. Mr.Lines represents the Royal Society of Chemistry on the British Standards Committee CPE 1014. He is indebted to the chairmen of the various working parties for assistance in the preparation of this report. Standardization of the Coulter Counter for Sizing and Counting J. G. Harfield Coulter Electronics Ltd., Luton, Bedfordshire In a previous short paper,' some aspects of standardization of the Coulter Counter were discussed and related to terminology such as reference, standard and control. The intention of this short talk is to expand on some of these aspects. By standardization I mean, of course, alignment of counters with standard materials and with each other.As the Coulter Counter theoretically measures two distinct and separate parameters, the number of particles and their volumetric size, a fundamental method of calibration is to relate the sum of all measured pulse heights (by count integration) to the total real volume of the analytical sample, using the particulate-displaced density and a chemical balance.* This makes the calibration dependent upon the accuracy of the counting procedure and the ability to measure the density in the chosen electrolyte solution. The method is clearly simpler if restricted to smooth non-porous spheres with a size range lying conveniently within the measurement span of the chosen aperture. The alternative method of calibration, one that is independent of counting, as it ought to be, and one that promises greater precision and accuracy as well as being more convenient for routine use, is to cross-reference the size scale to a reference technique such as optical or electron microscopy.In the past, size values quoted for materials for such cross-referencing have suffered from the differences naturally arising from the various kinds of average size produced by each method. In many instances the exact nature of the average size is not easily defined and a fit has to be established between a proposed theoretical size distribution and the experimental result. With the new, ultra-narrow materials available, with coefficients of variation typically <1%, differences in means become small compared with precision, and differences between distributions, for example normal and log-normal, are virtually zero.Unfortunately, aperture artefact broadening interferes with the accuracy of the results if conventional apertures are used, and this can lead to miscalibration3 unless the modal size is chosen as the point of calibration. At the moment, Coulter's reference material is a latex sized by independent workers using electron microscopy,4 but not certified by a competent independent authority. The values have been verified by techniques traceable to NBS material 1003 and to the chemical balance,5 but there is still a great need for a certifying authority, such as the NPL, to produce a suitable reference to which the commercial secondary standards can be tied. Such a reference must be applicable at a size such that errors of measurement in either reference technique or in the counter are no larger than the precision of the technique. A sub-micron reference has been certified recently by the American National Bureau of Standards, but the small size of the material (0.85 pm) and the range of recorded results throw doubt on both the reference method and its final use.6 No two methods seems to give close enough results to each other to lend confidence to the absolute value.One might suppose that in haematology, for example, calibration methods could be fully traceable and accurate. That is not yet the case. To calibrate for red cell volumes one uses a method analogous toMay, 1984 STANDARDISATION IN PARTICLE SIZING 163 count integration, whereby the total volume of red cells as measured by their centrifugally packed volume (or PCV) is divided by the number of cells.However, the PCV is known to be susceptible to trapped plasma, the amount varying with certain pathological and other conditions. Consequently, the reference method7 requires the trapped plasma to be measured by labelling (e.g., isotopically), but even this does not guarantee freedom from significant error because variable adsorption of plasma proteins on to cell surfaces can occur, making the trapping measurements unreliable.8 In practice, large numbers (20-50) of apparently normal blood specimens are spun and an average correction (3%) is applied to minimise this trapping error. Any residual error is relatively constant from calibration to calibration as long as the donor pool providing the blood specimens remains constant in composition.The over-all accuracy is probably +3%. Inter-laboratory variation is kept to a minimum, fortunately, by the use of assayed commercial control bloods, such as Coulter 4C control, with a much longer shelf life than routine blood specimens, the assay being obtained from instruments calibrated by the reference method. Although +3% by volume (+ 1% by diameter) seems to be reasonable by industrial standards, the size scale for the whole field of haematology is far from consistent. It is a matter of observation that the haematological PCV and the rigid sphere calibration do not agree, this being usually attributed to the red cells being non-spherical and deformable in the aperture. Counting No reference method for counting exists save the human eye.In most circumstances none is required. Excluding coincidence passage , a one pulse equals one particle relationship is acceptable throughout industry, where the essentially digital nature of modern counting circuits is well understood. In haematology, the accepted reference count is a semi-automatic Coulter Counter, for example the ZB, with manual large scale volumetric dilutions counted above or between specified size levels. The Coulter Thrombocounter is now recognised as a platelet reference counter. Blood samples are sent monthly to DHSS laboratories to monitor performance, and results are returned compared with the national mean (see Table I). TABLE I DHSS UKNEQAS (H). TRIAL No. 832352 Material: fixed human platelets.Coefficient of variation, Number of Instrument Mean Yo measurements CoulterSPlusSeries . . . . . . 108 9.6 114 Manual(Haemacyt0meter) . . . . 107 20.7 122 Technicon 105 15.5 39 Ortho . . . . . . . . . . . . 124 15.5 13 Coulter Semi-Auto (ZBI, etc.) . . 110 20.2 15 CoulterThromboCounter . . . . 110 16.8 199 Ultraflow 100 . . . . . . . . 118 24.0 16 x = 111.7 Mean weighted for observations Xw = 109.1 . . . . . . . . . . In the dairy industry the Breed smear9 (a quantitative nucleated cell count) is the reference technique. Cell size is of little interest, but cell concentration in milk is widely measured. This is a good example of the precision of a reference technique being vastly inferior to the routine analytical technique, the Coulter Counter. Because so few laboratories are equipped for microscopically counting large numbers of milks, it is often left to control reference laboratories to issue assays for cross-reference.Unfortunately, such assayed samples are rarely of a quality suitable for a reference, i.e., they are usually routinely obtained samples with a short life, perhaps only a matter of one or two days. Any discrepancies between the assays of these samples and the Coulter Counter are usually ascribed to incorrect size calibration of the counter. In order to improve this situation Coulter Electronics have recently introduced to the dairy industry a control milk, Somacount, consisting of a suspension of fixed, monosized cells suspended in a long shelf-life milk base. The reference method for its count is a very careful Coulter semi-automatic count of accurate bulk dilutions using the best techniques available.164 STANDARDISATION IN PARTICLE SIZING Anal.Proc., Vol. 21 Quality Control Once instruments have been calibrated, laboratories will want to know how consistent are their day to day results and how well they compare with other laboratories. Industrially, there is little standardization or comparison outside the large companies with several separate sites. The method usually chosen for such evaluations is the Ring Trial or Round Robin, in which one sample is circulated around the laboratories, or each receives an aliquot, for analysis by an agreed methodology. Because the final results are only as good as the quality of sampling and dispersion, it is essential that these form part of the methodology and are as strictly controlled as the analysis itself.Fig. 1 shows results for Ring Trials involving powder samples analysed by different laboratories on different models of Coulter Counter. Discrepant results are obtained when only the grand results mean is taken as reference with no control over the methodology. In a second trial, where the Coulter laboratory acted as a reference, issuing a strict methodology for sample preparation and analysis, the data showed a great improvement, Fig. 2. 100 2 3 4 5 6 7 8 9 2 3 4 5 6 7 8 9 1EO 1El 1 E2 Di arnetedpm Fig. 1. powder 1). Round Robin particle size trial (plastic Table I1 shows results from laboratories counting particle concentrations at various levels.Several different Coulter Counters are used, set to routine working sizes that may differ from each other by up to f2.5% by diameter. Note, the trial is intended only to measure inter-laboratory variance, not to provide average data. The scatter of values from all laboratories around the average data measures the over-all group quality control. The simplest inter-laboratory quality control for an industrial Coulter Counter is the plotting of calibration constants against time. Although with modern counters little or no amplifier drift is likely, a small, steady change in calibration might be anticipated with component ageing. Sudden significant changes can alert the operator to possible faults. 100 rn . ; 80 ui 60 a3 .- ti; 40 - =I f 20 0 0 1 EO 1El 1 E2 Diameter/pm Fig.2. powder 2). Round Robin particle size trial (plastic In haematology the derived blood indices of mean cell haemoglobin (MCH) and mean cell haemoglobin content (MCHC), which describe the individual nature of the red cell, are believed to beMay, 1984 STANDARDISATION IN PARTICLE SIZING 165 virtually constant for large populations of the human race. They thus offer an internal quality control possibility for haematology Coulter Counters. Further, it has been suggested that the size parameter for red cells also can serve the same function because, like the indices, it has a small coefficient of variation ( ~ 6 % ) for large numbers of blood samples.10 These properties have allowed the development of a sophisticated quality control algorithm for haematology Coulter Counters , taking means of indices from routine samples at relatively frequent intervals ( e .g . , every 20 samples) to alert the operator not only to the existence of an “out of control” condition but to elucidate, via inspections of the indices, the nature of the error. Routines such as these are built into the software of automated haematology analysers such as the Coulter S Plus series. TABLE I1 CELL COUNT MEANS FOR TEN INDIVIDUAL LABORATORIES, A TO H Sample Difference Laboratory from mean, A . . B . . c . . D . . E . . F . . E . . F . . G . . H . . x . . 1 . . 167 . . 158 . . 137 . . 324 . . 211 . . 145 . . 127 . . 174 . . 163 . . 152 . . 176 2 204 198 191 32 1 216 179 179 201 182 222 209 3 4 254 385 228 327 241 367 332 482 264 404 237 382 223 318 226 340 233 360 217 301 246 367 5 6 498 639 469 543 472 600 560 720 559 681.500 634 467 540 459 601 471 599 493 554 495 611 7 794 698 740 798 825 792 678 729 729 743 753 8 9 947 1030 835 916 862 975 941 1076 984 1101 917 1037 822 729 858 966 846 953 767 879 878 966 10 1142 1009 3 119 1177 1101 1167 1017 1104 1 093 1011 1094 mean 606 538 570 673 646 599 510 566 563 534 578 Yo 4.84 6.92 16.4 11.8 - 1.38 3.63 -11.8 -2.3 -2.60 -7.61 In non-haematological applications of the Coulter Counter, reliance will still need to be placed for the forseeable future on properly certified calibration and reference materials, suitably assayed for the relevant technique of use. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. References Harfield, J . G . , “Standardization of the Coulter Counter,” NPL meeting, Teddington, April 8th, 1981. B.S.3406; Part 5, 1983. Atkinson, C. M. L., and Wilson, R., Powder Technol., 1983, 34, No. 2, 275. Matthews, B. A., and Rhodes, C. T., J. Colloid Znterface Sci., 1970, 32, 339. Harfield, J . G., and Wood, W. M., in Groves, M. J . , and Wyatt-Sargent, J. L., Editors, “Particle Size Analysis 1970,” Society for Analytical Chemistry, London, 1972, p. 293. Standard Reference Material 1690, National Bureau of Standards, Washington, DC, USA, 1982. van Assendelft, 0. W., and England, J. M., “Advances in Haematological Methods: The Blood Count,” Hughes-Jones, N. C., and Gardner, B., Biochem. J . , 1962,83,404. Prescott, S. C., and Breed, R. S., J . Infect. Dis., 1910, 7 , 632. Bull, B. S . , and Korpman, R. A., in Cavill, I., Editor, “Quality Control,” Churchill Livingstone, Edinburgh, CRC Press, Boca Raton, FL, USA, 1982.1982, p. 121. Comparison of the Size Distribution of the ”BCR” Reference Quartz by ESZ and Image Analysis Techniques W. D. Griffiths and A. P. Rood Health and Safety Executive, Occupational Medicine and Hygiene Laboratories, 403 Edgware Road, London, Mm 6LN Since the introduction of the BCR reference quartz, work has been undertaken to characterise the material by use of a Coulter counter. We have similarly compared electrical sensing zone measurements with the results from gravitational sedimentometry , but have extended the characterisa- tion to include image analysis measurements of the particles’ projected area. To this end, a new method was employed to prepare the samples for microscopy.166 STANDARDISATION IN PARTICLE SIZING Anal.Proc., Vol. 21 From the work described above we have established a relationship between image analysis measurements and those from gravitational sedimentation which will be important in the long term studies that the Health and Safety Executive is conducting into the dynamic behaviour of dust particles. Introduction The Commission of European Communities, Community Bureau of Reference,' has made available a series of quartz reference dusts in the size range 0.1-1000 pm. Their sizes are certified either by gravitational sedimentation or by sieving. The HSE is primarily concerned with the occupational and environmental aspects of industrial dusts, i. e., their aerodynamic behaviour. Methods used for measuring size distributions of hazardous dusts tend, therefore, to concentrate on the smaller, respirable-sized particles.This means taking samples of airborne dusts, generally on membrane filters, and carrying out size analysis by using an optical microscope, or cyclones with a gravimetric assessment of the respirable component. This work is constrained to describe and present results from two methods, based on some of the fundamental principles of particle size analysis, which are used to characterise the BCR quartz reference dusts. The electrical sensing zone (ESZ) and microscope-image analysis methods were used and the results are compared with those available from BCR certification. Experiment a1 Procedure Size analysis of BCR 66, 67, 69 and 70 reference quartz was carried out by using the two methods.BCR 68 has a wide size range, which lies well outside the range of our interests. The ESZ method measures the equivalent volume of the particle and requires a sample that is well dispersed in a liquid electrolyte. To accomplish this dispersion, a small amount of the quartz sample was mixed with some Coulter liquid dispersant and then a little of it transferred into a solution of Isoton 11, the standard electrolyte. The mixture was then subjected to a short period of ultrasonic vibration to break down agglomerates and disperse the particles. The concentration of particulate in the electrolyte was set at such a level as to reduce the possibility of coincidence errors. Size analysis was carried out with a Coulter TAII.The correct aperture tube must be used for each dust. The instrument was calibrated with PVC - polystyrene latex spheres, supplied by the manufacturer. The microscope image anlysis system was a Leitz Orthoplan microscope coupled to a Joyce - Loebl Magiscan I. Measurements were made of the particles' projected areas by using transmitted light microscopy, the data then being auto-image analysed using a computer programme written by Kenny and Rood.2 From this the diameters of circles having equal projected areas as the particles and also the volume size distribution were computed. The magnification values set on the microscope and used for each test dust were optimized to suit the expected range of sizes. This will reduce truncation errors in the computed size distributions. During analysis, particles were selected by the programme at random so as to produce an unbiased distribution.This was further improved by having facilities for correct field edge handling in the programme. Several slides, containing the same test dust, were made up and analysed so as to ensure that enough particles were examined to provide a good statistical average. The image quality of each particle was enhanced by using a green interference filter (A = 544 nm) in the light source. One of the major problems with the optical microscope analysis of quartz was obtaining the sample in a stable form that is optically visible to ordinary transmitted light and is also an accurate size representation of the dust particles. A suitable method has been developed by Chung and Griffiths.3 A suspension of a small amount of the test dust is made with an approximately 0.1% solution of Na4P2O7.10H20 in deionized water. This is soon accomplished with the aid of ultrasonic vibration and a magnetic stirrer. Once the dust has been well dispersed, the suspension is filtered through a 25 mm, 0.1 pm pore size VC Millipore membrane filter. This is then slowly dried. The filter is next cleared and collapsed on to a regular glass microscope slide for optical examination, using the method of Le Guen and Galvin.4 Optical examination of such a slide, using transmitted light microscopy, gives an image which is not good enough for accurate size analysis. To counter this problem, the filter is etched, for a period of approximately 7 min, in an oxygen plasma in a Nanotech Plasmaprep P100.This is based on the preparation method developed for the optical examination of asbestos fibres by Le Guen et al.5 and Burdett et aZ.6 The sample on the slide is finally protected with a glass cover-slip and sealed down with a commercially available sealant. Microscopic examination of a sample prepared in such a way revealed quartz particles mounted in air, the surrounding filter material being etched away to a level below that of the base of the particles. Material directly beneath each particle was unaffected. The particles are left perched on pedestals of filter material.May, 1984 STANDARDISATION IN PARTICLE SIZING Conclusions A summary of the results is shown in Table 1. TABLE 1 COMPARISON OF 50% CUMULATIVE VOLUME DIAMETERS Results are given in micrometres.Material BCR certification ESZ Microscope BCR 66 1.1 1.3 2.2 BCR 67 10.5 10.4 11.2 BCR 69 37.0 41 .O 41.5 BCR 70 3.0 3.4 4.4 167 The ESZ results obtained in this work are in agreement with those of Atkinson and Wilson.7 The microscope derived results oversize for all dusts compared with the certified data. Previous work by Griffithsg showed that oversizing was even greater when the circumscribing circle method was applied. The greatest oversizing occurs with the smaller dusts, especially No. 66. Inaccuracies due to microscope limitations, and perhaps removal of the smallest particles during etching, may be the cause. In spite of these difficulties, use of the technique of optical microscopy with image analysis of the specially prepared sample is worthwhile, especially as the relationship between projected and sedimented distributions can be established.The automated nature of the Magiscan analysis makes the sizing of quartz particles, prepared as described, relatively easy and will be of much interest to those wishing to size analyse quartz or other mineral particle aerosols. References 1. 2. 3. 4. 5 . 6. Commission of the European Communities, BCR information, “Certification Report on Reference Kenny, L. C., and Rood, A. P., “Particle Size Analysis by Automated Image Analysis,” Proc. SPZE, 1982, Chung, K. Y. K., and Griffiths, W. D., Aerosol Sci. Technol., 1983, 2, 537. Le Guen, J. M. M., and Galvin, S., Ann. Occup. Hyg., 1981, 24, 273. Le Guen, J.M. M., Rooker, S. J . , and Vaughan, N. P., Environ. Sci. Technol., 1980, 14, 1008. Burdett, G., Le Guen, J. M. M., Rood, A. P., and Rooker, S. F . , in Benarie, M. M., Editor, “Proceedings of the 14th International Colloquium on Atmospheric Pollution, Paris, May 5-8, 1980.” Elsevier, Amsterdam, 1980, pp. 323-338. Atkinson, C. M. L., and Wilson, R., in Stanley-Wood, N . , and Allen, T., Editors, “Proceedings of the 4th Analytical Division of the RSC Particle Size Analysis Conference, Loughborough, 21-24 September 1981 ,” Wiley Heyden, Chichester, 1982, pp. 185-198. Materials of Defined Particle Size (Quartz BCR-46, 67, 68, 69, 70), EUR 6825 EN, 1980. 368, 119. 7. 8. Griffiths, W. D., HSE Report IR/L/FD/81/18, Health and Safety Executive, London, 1981. A Nomenclature for Mean Particle Diameters M.Alderliesten Unilever Research Laboratorium Vlaardingen, P. 0. Box 114, 3130 AC Vlaardingen, The Netherlands Introduction In particle-size analysis, not all the data on a particle-size distribution are always required or used.’ It is often more convenient to use one or more mean diameters to represent the whole distribution. Mean diameters then play a central role and it is, therefore, very important that the nomenclature for these parameters is unambiguous. In the literature on particle-size analysis, not only are different names used for one and the same mean diameter but also the same or very similar names are assigned to different mean diameters (see Table I). Even the set of mean diameters is often referred to as, for instance, average diameters,2 averages of particle size3 and statistical diameters.4 In this paper, recommendations are made for a systematic nomenclature aimed at avoiding any misunderstanding in regard to the actual meaning of individual means.Meaning of the Terms “Average” and “Statistical” As the term “average” is a familiar but elusive concept,j the terms “average diameters” or “averages of particle size” should not be used. Herdan6 uses the term “statistical diameters” for, for example,168 STANDARDISATION IN PARTICLE SIZING Anal. Proc., Vol. 21 Martin’s and Feret’s diameters “because a distance or intercept between two points on an individual particle has no claim to represent particle size in the aggregate. Only the average of a great many of such intercepts in a given group of particles can be regarded as a representative measure of particle size in that group.” Herdan’s terminology is used not only by Allen,’ Daviess and Cadleg but also by Martin10 himself.They use the adjective “statistical” to point out that an extra step of averaging over the particle shape is necessary to obtain relevant information about a (mean) particle size. Systematic Code One method of preventing ambiguity in mean diameters is systematic coding. The code used in the first co1um-n of Table I is derived from the general expression for mean diameters,4Jl defining the mean diameter Dp,q as: Cni D p W - q ) D p , q = [ h] , p f q * - * * * - * * * (la) 1 where ni = !he number of particles with diameter Di. For q = p, Dp,9 can be expressed as [ Cni In D i ] D,,,=exp .. . . . . . . . . . . (lb) ZFDP In practice, the use of p and q is confined to integer values. Although this code does eliminate ambiguity, it does not convey the physical meaning of a term such as, for instance, “mean volume diameter. ” and Then Naming Set of Mean Diameters In general, mean values Xof a variable X (say particle diameter) are defined in physics12 as well as in statistics13 as where wj is a measure of the relative importance or weight of Xi, with C wi = 1. The wi may be a function of Xi. The similarity of this definition to the definition of Dp,q in equation (la) becomes clear when the following substitutions are made in equation (2): . . . . . . . . . . . . . . x = c w i x i . . (2) n,D? C ni D; Wi= - I xi= xq It is now clear that the mean value of the averaged variable, Kq, should be denoted by - ,t = DP-9 .. . . . . . . . . . . By definition: [Dp,91p9:=DpB,p#q (3) Dp-q: = [ Dp-q]l’@-q),p # q (4) . . . . . . . . . . As the meaning of bbmean values” can be regarded as being equal to “mean diameters,” because “diameter” is merely the name of the relevant value, we may conclude that the term “mean diameters” can be used for the set {Dp,9}. Systematic Nomenclature for Mean Diameters On the basis of the reasoning set out in the preceding section, it is possible to develop a systematic nomenclature for mean diameters by indicating explicitly the name of the averaged variable and the name of the weight assigned to it. Although this approach may seem slightly artificial, it will be demonstrated afterwards that the nomenclature has a significant physical meaning.May, 1984 STANDARDISATION IN PARTICLE SIZING 169 To start with, the principle of indicating the name of the averaged variable and the name of the assigned weight can be demonstrated by two examples: The variable to be averaged is the particle diameter D.The assigned weight to particles with diameter Di is their relative surface. Thus, 03.2 can be designated as the surface-weighted mean diameter. (ii) Here, the assigned weight is the relative volume of the particles. b 4 , 3 can, therefore, be called the volume-weighted mean diamete_r. According to this system, D2,1 is called the diameter-weighted mean diameter and D1,0 the number-weighted mean diameter. The nomenclature developed so far covers mean diameters Dp,q for which p --q = 1.For mean diameters Dp,q, for whichp - q 2 2, names can be derived along the following lines. ( D2,0will serve as an example.) If the variable D,2 refers to the surface of a particle with diameter Di (except for a shape factor), equations (la) and (3) lead to the conclusion that should be called the number-weighted mea? surface, because the variable to be averaged, 0 2 . has the dimension of a surface. the square root of [D2,# can then be indicated by adding the word “diameter”: b 2 , 0 = number-weighted mean surface diameter. We omit “number-weight_ed” as being the most trivial case, so that 0 2 . 0 = mean surface diameter. For reasons of similarity, D3,* is called mean volume diameter. This nomenclature links up with _that used by, for example, Underwood.4 In accordance with the above reasoning, DIAO should be simply called “mean diameter.” It is obvious that the name arithmetic mean diameter for Dl,o, proposed by Underwopd (see Table I), does not fit our system proposed.The same holds for the geometric mean diameter and the harmonic mean diameter D-l,O. In fact, the adjectives “arithmetic,” “geometric” and “harmonic” fall outside the system of names presented here and systems proposed elsewhere, because they have nothing to do with some particle property such as volume, surface, etc. Neither the reciprocal diametsr &-I, being the averaged quantity in D-l,O, nor the logarithm of Di, being the averaged quantity in Do,o, has a physical meaning. The adjectives mentioned above stem from the field of mathematics, see, for example, the theory of infinite series.Here we have the harmonic and the geometric series. Nevertheless, we would TABLE I CROSS-REFERENCE TABLE FOR MEAN DIAMETERS m = mean; d = diameter. Systematic Mugele and code Allen’s B.S. 2955: 1958 Cadle19 Evans5 Underwood4 This paper D, .” Number, length Numerical m.d. m.d.; arithmetic m. D2,o Number, surface Equivalent m.d. surface m.d. 0 3 , ” Number, volume Equivalent m.d. volume m.d. &I Length, surface Linear m.d. m.d. D3.2 Surface, volume Surface m .d . D4.3 1:; }km;.ment Volume m.d. Volume D3,l Length, volume - m.d. Arithmetic m. Linear m.d. m. surface d. Surface m.d. m. mass d. Volume m.d. Linear m.d. Surface d.m. Surface m.d. Sauter m.d. Mass m.d.De Brouckere m.d. - Volume d.m. Arithmetic Arithmetic m.d. m.d. m. surfaced. m. surfaced. m. volume d. m. volume d. m. length d. Diameter- weighted m.d. m. volume- Surface- surface d. weighted m.d. d. Volume- weighted m.d. weighted m. surface d . m.[;;;;} - Diameter-STANDARDISATION IN PARTICLE SIZING Anal. Proc., Vol. 21 170 propose the names arithmetic, geometric and harmonic mean diameter for bl,o, and b-l,o, respectively. The adjective “arithmetic” is then used to avoid confusion in regard to the name “mean diameters” for the set {Dp,q}. The other two adjectives do not give rise to difficulties, because they do not interfere with our system of names. Moreover, there is hardly any confusion about these names in the particle-size literature. Application of the above principles to the mean diameter D5,3, leads to the name volume-weighted mean surface diameter.This can be made clearer by stating that the equation for D5,3 can be rearranged into the form: Similarly, any mean diameter can be given a name as long as there is a name for the weight and the physical property to be averaged (volume, surface, etc.). The system may even be extended to so-called weighted geqmetric mean diameters and therefore we include the word “geometric” and also the mean diameters Dp,q, for which p = q. For example, In D i ] The variable to be averaged in this expressiop is the logarithm of D and the assigned weight is the relative volume of the particles. Therefore, D3,3 has to be called volume-weighted geometric mean diamet_er .As Dp,q = b , , , our nomenclature now covers the whole field of mean particle diameters. A complete list is given in Table 11. TABLE I1 NOMENCLATURE FOR MEAN PARTICLE DIAMETERS Dp,q Systematic code &,.* . . D0,o . . . . Dl.0 . . . . D 2 . 0 . . ’ . D2.1 * * . . 0 4 , 3 . * . f 85.3 . . . . 0 5 . 2 . . . . 8 6 . 3 . . . . p1.1 . . . . D 3 . 3 . . . . D 3 . 0 . . . * 0 3 . 2 . . . . 03.1 . . . . 0 4 . 2 . . . . 0 4 . 1 * * . * 0 2 . 2 . . . . Names . . Harmonic mean diameter . . Geometric mean diameter . . Arithmetic mean diameter . . Mean surface diameter . , Mean volume diameter . . Diameter-weighted mean diameter . . Surface-weighted mean diameter , , Volume-weighted mean diameter . . . . . . . . . . . . . . . . , , Diameter-weighted mean surface diameter Surface-weighted mean surface diameter Volume-weighted mean surface diameter Diameter-weighted mean volume diameter Surface-weighted mean volume diameter Volume-weighted mean volume diameter Diameter-weighted geometric mean diameter Surface-weighted geometric mean diameter Voiume-weighted geometric mean diameter Physical Relevance of the Nomenclature The application of the mean diameters Dp,q requires a profound knowledge of their physical meaning. In a sense, this holds also for their nomenclature.Therefore, the physical relevance of the nomenclature developed will be dEmonstrated for a number of mean particle diameters. Volume-weighted mean diameter, D4,3 This mean diameter can be calculated from, for example, sieye or sedimentation measurements. The volume vi of material in the ith fraction is proportional to niDi, where Di is the mid-point diameter of the ith fraction.ThusMay, 1984 STANDARDISATION IN PARTICLE SIZING 171 Obviously, for Dj4,3 the relative importance or weight of each mid-point diameter is given by the volume or mass of the corresponding sieve_ or sediment fraction. Surface-weighted mean diameter, D3.2 According to the method of measurement14 D3,2 is frequently denoted as volume-surface mean diameter. However, this does not rule out the name we propose, because D3,2 can _also be determined by a combined sieve - surface measurement. From the surface per sieve fraction D3,2 is calculated: ni D f D 3 . 2 = F s D i i I 1 Surface-weighted geometric mean diameter, D2,2 A visual ranking of photographs of air bubble distributions seems to coincide with their D2,2 ranking.15 In the light of Weber - Fechner's law, a logarithmic averaging of bubble sizes by eye seems plausible, whereas the relative importance of bubbles on the photographs is given by their surfaces: The physical meaning of the nomenclature of & 0 and &,o is self-evident and elucidation has therefore been left out. Discussion developed in Germany.16J7 The relationship between the German notation xk,q and our notation is fairly simple: if k = p - q , with and The systematic coding Dp,9 in this paper is widely used, but an alterna_tive notation has been, x k , q D p , q ( 5 ) x k , 9 = kvMk,9 .. . . . . . . . . . . M k , q = JXmaxXkfq (X) dX Xmin If q = 0, f,(X) is the number distribution and if q = 3 , f q ( X ) is the volume distribution.In fact, the indices in the German notation reflect the averaged quantity (= index k ) and the assigned weight (= index q ) , which we have used to develop the nomenclature of mean diameters. In spite of this property of the German notation, the notation Dp,q is preferred. The reasons in favour of the notation Dp,? are that it is easier to use and more widely applied, and that geometric mean diameters are defined. Geometric mean diameters XO,,, equivalent to D , , apparently do not exist in the German system (references 16 and 17 and DIN 66 141). This gap is demonstrated by the following theoretical consideration?: the moments MO,q are normalising conditions and by definition equal to unity. The definition of Xk,, in equation ( 5 ) may then suggest that Xo,q = "t/l does not exist; in the definition of the lognormal distribution function167*0 the median of the distribution is used as the central value, instead of the geometric mean, which is required by the (statistical) theory of distribution functions.Basically, a system of trivial names of mean particle sizes will prove inadequate when mapping the two-dimensional system of names (the weight and the averaged variable) on to a one-dimensional system of names, for the following reasons: two different means may have similar or identical trivial names (not a one-to-one mapping); the trivial name of a mean may be similar to a name of another mean from another system of names. Although our approach does not always result in concise designations, we feel it is free from ambiguities, as a name is built up of the name of the averaged variable and that of the weight assigned to it. An advantage of our nomenclature is that it can be used irrespective of the notation system adopted. The author wishes to thank Mr. A. G. Flook of the Unilever Research Colworth Laboratory, Sharnbrook, Bedfordshire, for stimulating discussions.172 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. LOW LEVEL ORGANIC CONTAMINATION OF WATER References Anal. Proc., Vol. 21 Underwood, E. E., “Quantitative Stereology,” Addison-Wesley, Reading, MA, USA, 1974, p. 140. Allen, T., “Particle Size Measurement,” Chapman and Hall Ltd., London, 1975, p. 85. Herdan, G., “Small Particle Statistics,” Butterworths, London, 1960, p. 29. Underwood, E. E., “Quantitative Stereology,” Addison-Wesley, Reading, MA, USA, 1974, p. 103. Kendall, M. G., and Buckland, W. R., “A Dictionary of Statistical Terms,” Oliver and Boyd Ltd., Herdan, G., “Small Particle Statistics,” Butterworths, London, 1960, pp. 19 and 45. Allen, T., “Particle Size Measurement,” Chapman and Hall Ltd., London, 1975, p. 76. Davies, C. N., Nature, 1962, 195, 768. Cadle, R. D., “Particle Size,” Reinhold, New York, 1965, p. 4. Martin, G., Trans. Ceram. SOC. (Eng.), 1923, 23, 61. Mugele, R. A., and Evans, H. D., Znd. Eng. Chem., 1951,43, 1317. Marton, L., “Methods of Experimental Physics,” Volume 1, Academic Press, New York, USA, 1959, p. 4. Kendall, M. G., and Stuart, A., “The Advanced Theory of Statistics,” Volume 1, Charles Griffin, London, Herdan, G., “Small Particle Statistics,” Butterworths, London, 1960, p. 35. Alderliesten, M., unpublished results. Rumpf, H., and Ebert, K. F., Chem. Zng. Tech., 1964, 36,523. Leschonski, K., Alex, W., and Koglin, B., Chem. Zng. Tech., 1974,46,23. Allen, T., “Particle Size Measurement,” Chapman and Hall, Ltd., London, 1975, p. 89. Cadle, R. D., “Particle Size,” Reinhold, New York, 1965, p. 30. Leschonski, K., Alex, W., and Koglin, B., Chem. Zng. Tech., 1974,46, 101. Edinburgh, 1960, p. 17. 1958, p. 51.

ISSN:0144-557X    

DOI:10.1039/AP9842100159

出版商:RSC    

年代:1984

数据来源: RSC

摘要:

172 LOW LEVEL ORGANIC CONTAMINATION OF WATER Anal. Proc., Vol. 21 Low Level Organic Contamination of Water: Its Measurement and Significance The following is a collective summary of the introductory address and three of the papers presented at a Joint Symposium organised by the Environment Group of the Industrial Division and the Analytical Division held on October 19th, 1983, at the Scientific Societies Lecture Theatre, London, W.l. Conventional summaries of the other three papers, by Dr. D. E. Games, Dr. G. W. Aherne and Messrs. S. P. Scott and R. J. Vincent, follow the collective summary. Summary M. L. Richardson 6 Birch Drive, Maple Cross, Rickmansworth, Hertfordshire, WD3 2UL Dr. P. A. Gilbert for the Environment Group introduced the Chairman, Professor J. W. Bridges (University of Surrey).Professor Bridges indicated that the attendance of over 100 showed the considerable importance being placed on the measurement and significance of organic micro- pollutants. He stated that over 3000 organic compounds had been reported as being measured in various water samples, and these could originate from natural sources, industrial plants, agricultural practice, water and sewage treatment, water pipes, domestic discharges and transport. The matter was complicated by the fact that chemicals released to the aquatic environment might be converted by abiotic or biotic processes to other products. The major concerns related to the presence of micro-contaminants in water included: sensory (i.e., manifested in taste, odour, etc.); toxicological (involves lifetime exposure to all members of the population); and emotive (belief in the concept of pure/wholesome water).Possible human intake or exposure could arise from the ingestion of food and water (2-3 1 d-1, there is no basis for calculating the volume from processed food), uptake through bathing and washing and medical treatment, e.g., dialysis, infusion, etc. Sources of information in assessing toxic hazards included animal and in vitro toxicological tests on individual chemicals in water fractions, epidemiological findings and structural relationships to known toxic chemicals. There were particular problems in interpreting epidemiological data including the need to ascertain the adequacy of the control group, the amounts of exposure levels in retrospective studies (usually not known), the fact that exposure was invariably to many chemicals, a number ofMay, 1984 LOW LEVEL ORGANIC CONTAMINATION OF WATER 173 which would not have been identified, while others would often show greatly changing levels over the period of the study, the fact that it was very difficult to assess the life style contribution to any disease and that criteria for the identification of disease and efficiency in detection change with time. There were also potential problems in the use of animal and/or in vitro toxicological data for assessing potential hazards because the doses used were often much higher than the levels to which man was likely to be exposed and hence conditions were quite different, the test species may not have shown human responses and the tests themselves may not have been able to assess variable response because of the range of population exposed, e.g., the age, sex, disease or genetic variability of the exposed population, and the fact that the chemical in question would be present in admixture and additive, synergistic and antagonistic effects might need to be considered.In discussing the World Health Organisation guidelines for drinking water Professor Bridges considered that these were related more to the ability of the analyst than to the chemicals which might actually be present. He also indicated the difference in levels in the WHO guidelines when compared with workplace exposure. The first lecture by Dr. A. Waggott and Mr. K . Connor of the Water Research Centre, Stevenage, was entitled “Analysis of Sulphonic Acids and other Ionic Organic Compounds using Reversed-phase HPLC.” They indicated that the determination of ionic organic compounds in aqueous samples by reversed-phase liquid chromatography posed problems not encountered with more non-polar organic compounds, e.g., polynuclear aromatic hydrocarbons.The ionisation of sulphonated organic compounds had to be suppressed by the use of ion-pairing reagents,l by rendering the eluted solvent acidic or by the use of more polar reversed-phase packings.2 These techniques for ionic suppression could themselves be a problem, particularly when an in situ pre-concentration of the organic compound was required prior to HPLC separation.* Dr. Waggott gave examples of reversed-phase HPLC in the analysis of fluorescent whitening agents and certain Acid Blue dyestuffs in water samples. In concluding he mentioned the potential advantages of microbore columns , multi-dimensional work and post column reaction detection systems, particularly those using atomic-spectroscopic detection.Dr. E. Longstaff (ICI Toxicology Laboratory) and Dr. J. R. Lawrence (ICI Brixham Laboratory) spoke on “The Application of Mutagenicity Tests to the Determination of Water Quality.’’ The chemical industry was aware that many of its raw materials, by-products and products reached the aquatic environment by various routes, It was concerned to play its part in ensuring that the highest standards were maintained in the quality of our daily water supply and to co-operate in the identification and removal of possible causes of cancer.Certain in vitro tests were rapid and inexpensive methods of identifying possible mutagens. The relevance of the Ames test in testing water supplies was then discussed, together with its value as a research tool and/or as a routine screen in this context. Stress was laid on the need to allocate resources to have the maximum beneficial effect on human health and to avoid the possibility of generating alarm through inadequate interpretation of test results. They emphasized that any environment was potentially dangerous. There was a requirement for a high quality water supply. Tests needed to be cost effective for the identification of cancer inducing compounds, which in turn would require removal to ensure safety.In vitro tests needed to be accurate, comparable and applicable. They were currently research tools and hence they should not be embodied into water quality criteria. Mr. M . L. Richardson and Miss J . M. Bowron (Thames Water), in the final paper, described a predictive technique “Catchment Quality Control-an Alternative Approach.” Catchment Quality Control (CQC) was a means of predicting the presence, fate and significance of organic chemicals that might be present in river waters which were subsequently abstracted for potable supply purposes. It was complementary to analytical chemistry, because it was realised that GC - MS surveys of rivers and potable waters would only detect approximately 20% of compounds. More specialised, and often very time-consuming techniques had to be developed for the majority of compounds.CQC ascertained most of the compounds being discharged by major industrial and commercial premises, and predicted the concentrations at the relevant water abstraction points. Detailed consideration was given to those compounds on which satisfactory data on degradability and innocuousness were not readily available.3174 LOW LEVEL ORGANIC CONTAMINATION OF WATER Anal. Proc., Vol. 21 Both published and manufacturers’ data were studied with the aim of assessing the long-term public health risks of each compound. In many instances, it was deemed necessary to consider metabolism or degradation products, or even the results of chemical interactions. The meeting concluded with a very lively discussion in which the importance of the significance and environmental impact on determined and predicted low level organic contaminants in water was stressed.References 1. Concerted Action Analysis of Organic Micropollutants in Water. Activity Report of the Commission of the European Communities, COST Project 64b BIS covering the period October 1978-December 1981, Volume 2, OMP/29/82-XIIlENVl17l82, 1982. Concerted Action Analysis of Organic Micropollutants in Water. Activity Report of the Commission of the European Communities, COST Project 64b B/S, meeting of September 19-21, 1983, in the press. Richardson, M. L., and Bowron, J. W., “Catchment Quality Control,” Notes on Water Research No. 32, Water Research Centre, Medmenham, 1983. 2. 3. Application of LC - MS to the Analysis of Water David E.Games M. Glenys Foster and 0. Meresz Ontario Ministry of the Environment, P. 0. Box 213, Rexdale, Ontario, M9W 5L1 , Canada Combined gas chromatography - mass spectrometry (GC - MS) is used extensively for the analysis of organic compounds in water. The technique provides a sensitive and specific method for the qualitative and quantitative analysis of organic compounds that are volatile and thermally stable. However, it has been estimated that only between 10 and 20% of organics present in water are amenable to study by this approach, because of their low volatility and/or thermal instability. High-performance liquid chromatography (HPLC) has become the method of choice for the analysis of compounds of this type. The technique also has advantages for the study of many classes of compound which are amenable to GC because, by use of trace enrichment techniques, such as pre-column concentration, water samples can be directly analysed without the necessity of using extraction techniques.A combined system for high-performance liquid chromatography/mass spectrometry (LC - MS) should enable the types of water analysis currently undertaken by GC - MS to be extended to a wider range of compounds. An additional benefit is the provision of a more universal detection system for the liquid chromatograph. It is not the purpose of this paper to review systems for LC - MS. The reader is referred to recent review articles on the subject.’-13 A brief description of the three most widely used systems for LC - MS will be given and areas of application relevant to water analysis will be described.This will be followed by a brief description of our studies in this area. Department of Chemistry, University College, P. 0. Box 78, Cardijf, CFl 1XL Systems for LC - MS The simplest approach to LC-MS consists of feeding a portion of the eluent from the liquid chromatograph into the ion source of a mass spectrometer configured for chemical ionization (CI) mass spectrometry. Solvent mediated CI mass spectra are produced. If conventional LC columns are used the system has limited sensitivity. However, the use of microbore LC enables all of the eluent to be fed into the mass spectrometer ion source, resulting in excellent sensitivity.14 Systems of this type are commercially available from Nermagls and Hewlett-Packard16 and simple systems can be readily constructed in one’s own laboratory.This type of system is commonly referred to as direct liquid introduction. A related system is available from Kratos Analytical Instruments. l7 A second approach involves the removal of solvent using a continuously moving belt. The LC eluent is fed on to the belt and solvent is removed by use of an infrared heater and two vacuum locks. The residua1 solute is flash vaporized into the ion source of a mass spectrometer, where conventional electron impact (EI) and chemical ionization (CI) mass spectra can be obtained. Systems of this type are available from Finnigan MAT18319 and VG Analytical.20May, 1984 LOW LEVEL ORGANIC CONTAMINATION OF WATER 175 Recently, a third system has been developed which shows considerable potential for the analysis of compounds that are difficult to handle by conventional mass spectroscopic techniques.2l The system is referred to as thermospray ionization.A buffered mobile phase is passed through a stainless-steel capillary at flow-rates between 0.5 and 2 ml min-1. The end of the capillary is electrically heated. A supersonic jet of vapour containing solute ions is produced which traverses the ion source of a mass spectrometer and enters into a 1 cm diameter pumping line, which is connected to a mechanical vacuum pump. A conical exit aperture is sited at right angles to the jet and ions are sampled through it into a quadrupole mass analyser. Impressive LC - MS data have been obtained with the system on a range of compounds which have proved difficult to handle with other systems.Currently, the system is available from Vestec and Finnigan MAT.22 Applications of LC - MS to the Analysis of Water Samples In the early stages of development of LC - MS, studies were mainly confined to elucidating the types of compound that were amenable to study by the various types of interface. Most studies have been of a qualitative nature, although it has been shown that the three types of interface referred to earlier are capable of providing quantitative data. More recently, real applications using LC - MS to identify organic compounds in water have appeared. Detailed studies of the LC - MS behaviour of a group of 19 carbamate pesticides using a moving belt interface have been reported.23 It was shown that compounds of this type could be quantified down to the low nanogram level.However, the studies were conducted on a prototype system and recent developments should yield improved data. Other studies have confirmed the findings in this investigation and have shown that the technique can be used for the analysis of carbamate and urea pesticides in crop residues at the p.p.m. leve1,24 and that aldicarb, aldicarb sulphoxide and aldicarb sulphone can be analysed in well water samples down to the p.p.b. leve1.25 Other classes of potential environmental contaminants which have been studied with moving belt systems include perchloro cage pesticides,26 chloropropham and its metabolites,27 chlorophenolszg and polychlorinated biphenyls and their metabolites.29 Interfaces of the direct liquid introduction type have been used to study the LC - MS of organophosphorus pesticides ,30 triazine31 and phenylurea herbicides in river water samples.32 The applications described so far are of the target analysis type, where a specific compound or group of compounds is being sought.This type of approach means that many potentially hazardous compounds can be overlooked. LC - MS has the ability to be used for wider types of investigation. The usefulness of a moving belt interface for analysis of water samples in this context has been assessed.33 Because of the high chemical background and the system being unable to handle aqueous mobile phase systems without splitting off some of the mobile phase, it was concluded that the approach has limited suitability for compounds present in low concentrations.The use of microbore LC34 and spray deposition35 with interfaces of this type overcome some of the problems encountered in this study. Studies of tannery effluents using a moving belt system illustrate the merits of the approach.36 Twenty different compounds were identified by LC - MS and one of the major components was found to be binaphthyl sulphone, which was not identified in gas-chromatographic studies of the same sample. Studies of Test Well Samples from a Landfill Site by LC - MS We have been investigating the usefulness of LC - MS, together with other mass spectral techniques, for the analysis of extracts of test well samples from landfill sites.Extracts are studied by LC - MS and capillary GC-MS, using both EI and CI mass spectrometry. In addition, relative molecular mass profiling of the extracts is carried out by use of field desorption and desorption chemical ionization mass spectrometry. The latter measurements serve as a check for loss or decomposition of sample during a GC - MS or LC - MS study. Fig. 1 shows the computer reconstructed total ion current trace obtained under EI LC-MS conditions, using a moving belt interface, from a basic fraction of one of our extracts. Examination of the EI and CI mass spectral data enables most of the major components and many of the minor components present in the sample to be identified. The main components are substituted benzothiazoles, together with aromatic amines and chlorinated phenols.These last compounds, because of the complexity of the sample matrix, were carried over into the base fraction in our extraction procedure. Comparison of the GC - MS and LC - MS data showed that the two techniques were mutually complementary. Low volatility thermally labile compounds not found by GC - MS were found using LC-MS and some compounds of high volatility were observed by W - M S but not by176 LOW LEVEL ORGANIC CONTAMINATION OF WATER Anal. Proc., Vol. 21 0 10 20 30 Time/m in 0 Fig. 1. Computer reconstructed total ion current trace obtained from the base fraction of an extract from a test well sample using EI LC - MS with a moving belt interface. A 200 x 5 mm column packed with 5 pm Hypersil ODS was used with a mobile phase initially of acetonitrile -water (1 + 1) changed to (8 + 2) after 12 min.A mobile phase flow-rate of 1 ml min- was used, approximately 10% of which was fed onto the LC - MS interface. LC - MS. In addition, the differences in chromatographic behaviour enabled better identifications to be made of multi-component chromatographic peaks, as compounds not resolved by capillary GC - MS were resolved by LC - MS and vice versa. Recently, we have found37 that use of microbore LC - MS enables considerable advantages to be gained in studies of this type, particularly when reverse-phase LC is being performed. All of the eluent from the liquid chromatograph can be handled by the LC - MS interface, the sensitivity in terms of sample amount injected on-column is improved and high percentage aqueous mobile phases are more readily handled. Conclusions LC-MS can add a new dimension to studies of water samples, enabling low volatility and/or thermally labile organic compounds to be more readily identified.The choice of interface depends on the class of compound and type of investigation being pursued. The advent of interfaces of the thermospray type of LC-MS enables the range of compounds that can be studied to be extended to ionic compounds, which present difficulties in analysis by other types of interface. We thank the SERC and Royal Society for assistance in the purchase of mass spectral and chromatographic equipment. 1. 2. 3. 4. 5. 6. 7. 8. 9. References Arpino, P. J., and Guiochon, G., Anal. Chem., l979,51,682A. Arpino, P.J., in Vickrey, T. M., Editor. “Liquid Chromatography Detectors,” Marcel Dekker, New York, McFadden, W. H., J. Chromatogr. Sci., 1979, 17,2. McFadden, W. H., J . Chromatogr. Sci., 1980, 18, 9. McFadden, W. H., Anal. Proc., 1982, 19, 258. Games, D. E., Anal. Proc., 1980, 17,110,332. Games, D. E., Biomed. Mass Spectrom., 1981, 8, 454. Games, D. E., in Morris, H. R., Editor, “Soft Ionization Biological Mass Spectrometry,” Heyden, London, Games, D. E., in Giddings, J. C., Grushka, E., Gazes, J., and Brown, P. R., Editors, “Advances in 1983, p. 243. 1981, p. 54. Chromatography,” Volume 21, Marcel Dekker, New York, 1983, p. 1.May , 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 1984 LOW LEVEL ORGANIC CONTAMINATION OF WATER 177 Knox, J.H., Anal. Proc., 1982, 19, 166. Levsen, K., in Bjgrseth, A., and Angeletti, G., Editors, “Analysis of Organic Micropollutants in Water,” D. Reidel, Dordrecht, 1982, p. 149. Curry, Z. F., J. Liq. Chromatogr., 1982, S(Sup. 2), 257. Willoughby, R. C., and Browner, R. F., in Lawrence, J. F., Editor, “Trace Analysis,” Volume 2, Academic Henion, J. D., and Maylin, G. A., Biomed. Mass Spectrom., 1980, 7 , 115. Arpino, P. J., Bounine, J. P., Dedieu, M., and Guiochon, G., J. Chromatogr., 1983, 271, 43. Melera, A., Adv. Mass Spectrom., 1980, 8B, 1597. Chapman, J. R., Harden, E. H., Evans, S., and Moore, L. E., Znt. J. Mass Spectrom. Zon. Phys., 1983,46, McFadden, W. H., Schwartz, H. L., and Evans, S., J. Chromatogr., 1976, 122,389.Dobberstein, P., Korte, E., Meyerhoff, G., and Pesch, R., Int. J. Mass Spectrom. Zon Phys., 1983,46,185. Millington, D. S., Yorke, D. A., and Burns, P., Adv. Mass Spectrom., 1980, SB, 1819. Blakely, C. R., and Vestal, M. L., Anal. Chem., 1983, 55,750. McFadden, W. H., Spectra, 1983, 9, 23. Wright, L. H., J. Chromatogr. Sci., 1982, 20, 1. Cairns, T., Siegmund, E. G., and Doose, G. M., Biomed. Mass Spectrom., 1983, 10, 24. Wright, L. H., Jackson, M. D., and Lewis, R. G., Bull. Environm. Contam. Toxicol., 1982,28,740. Cairns, T., Siegmund, E. G., and Doose, G. M., Anal. Chem., 1982,54, 953. Games, D. E., and Weerasinghe, N. C. A., J. Chromatogr., Sci., 1980, 18, 106. Wright, L. H., Edgerton, T. R., Arbes, S. J., Jr., and Lores, E. M., Biomed. Mass Spectrom., 1981,8,47S.Dymerski, P., Kennedy, M., and Kaminsky, L., in Hertz, H. S . , and Cheder, S. N., Editors, “Trace Organic Analysis: A New Frontier in Analytical Chemistry,” N.B.S., Washington, DC, USA, 1979, p. 685. Press, New York, 1982, p. 69. 201. Parker, C. E., Haney, C. A., Harvan, D. J., and Hass, J. R., J. Chromatogr., 1982,242,77. Parker, C . E., Haney, C. A., and Hass, J. R., J. Chromaiogr., 1982, 237, 233. Levsen, K., Schafer, K. H., and Freudenthal, J., J. Chromatogr., 1983, 271, 51. Schauenberg, H., Schlitt, H., and Knoppel, H., in Bjgrseth, A., and Angeletti, G., Editors, “Analysis of Alcock, N. J., Corbelli, L., Games, D. E., Lant, M. S., and Westwood, S. A., Biomed. Mass. Spectrom., Hayes, M. J., Lankmayer, E. P., Vouros, P., Karger, B. L., and McGuire, J.M., Anal. Chem., 1983,55, Thruston, A. D., Jr., and McGuire, J. M., Biomed. Mass Spectrom., 1981,8,47. Foster, M. G., Meresz, O., Games, D. E.: Lant, M. S., and Westwood, S. A., Biomed. Mass Spectrom., Organic Micropollutants in Water,” D. Reidel, Dordrecht, 1982, p. 193. 1982, 9, 499. 1745. 1983, 10, 338. Use and Significance of lmmunoassays in the Analysis of Water G. W. Aherne Department of Biochemistry, University of Surrey, Guildford, Surrey The first radioimmunoassay (RIA) was described in 19601 for the measurement of insulin in human plasma. Since then the technique has been widely applied, not only in clinical chemistry, but also in such diverse fields of study as endocrinology, immunology and pharmacology, as well as in forensic, veterinary and food sciences.Although RIA has been the most widely used technique, other types of immunoassay , e.g., enzyme immunoassay (EIA) and fluoroimmunoassay (FIA) have become popular and can be readily adopted in laboratories without existing facilities and the expertise often required for radioimmunoassay. In spite of their attributes of high sensitivity and specificity, immunoassays have not yet been widely applied to the analysis of water contaminants. Immunoassays are attractive, cost effective alternatives to more conventional techniques, such as gas chromatography, high-performance liquid chromato- graphy and mass spectrometry. Also, they are useful for screening large numbers of samples prior to analysis by more sophisticated and expensive techniques. Few problems should be encountered in adapting existing immunoassays, primarily designed for other purposes, to the analysis of water.Principles of Radioimmunoassay RIA depends on the competition of an antigen and a fixed amount of a radiolabelled form of that antigen for a limited number of antibody binding sites. At the end of a period of incubation the178 LOW LEVEL ORGANIC CONTAMINATION OF WATER Anal. Proc., Vol. 21 antibody bound fraction and the unbound fraction are separated from each other in a procedure known as phase separation. Methods which exploit physical, chemical or immunological differences between the two fractions can be used. The most commonly used phase separation agents are dextran coated charcoal (absorbs free fraction), ammonium sulphate (precipitates antibody bound fraction) and double antibody immunological precipitation by a second antibody specific for the immunoglobin of the first antibody.Many assays now utilise solid-phase techniques, so that phase separation can be achieved by simple centrifugation and washing steps. The distribution of radioactivity between the bound and free fractions is related to the amount of standard antigen added and then unknown concentrations of antigen can be determined. The same principles apply to other forms of immunoassay, where the radiolabel is replaced by, for example, an enzyme or fluorimetrically labelled antigen, the distribution of which is measured following phase separation using appropriate instrumentation. More detailed information on the principles of immunoassays can be obtained from some excellent reviews.2-3 Two key reagents are thus required in order to set up an immunoassay: a suitable antibody to the analyte and a labelled form of that analyte.Antibody Antisera to a wide range of substances are now available commercially or can often be obtained from various laboratories with supplies in excess of their needs. If a source of antibodies is not readily available, antisera can be produced in one of a number of laboratory animal species using suitable immunisation schedules. Molecules of less than 5 000 relative molecular mass are not normally immunogenic and must first be conjugated to a carrier protein such as bovine serum albumin, ovalbumin or y-globulin. For use in immunoassays antibodies should be of high avidity and exhibit the desired specificity.The specificity of an antiserum depends on a number of factors, e.g., the purity of the immunising preparation with polypeptide hormones or the chemical nature of the hapten - protein conjugate with small molecules, as well as the individual response of each immunised animal. Absolute specificity for an analyte is difficult to achieve as most antisera cross-react, to some extent, with closely related compounds. The usefulness of each antiserum should be carefully assessed for each particular application and results obtained interpreted in the light of the cross-reactivity data. Antisera that exhibit a low degree of cross-reactivity with a closely related compound, for example, metabolite, can often be used successfully as the cross reactant is likely to be bound less avidly than the analyte. This is particularly so if the cross reactant is present in much lower concentrations than the analyte.If necessary, absolute specificity can be achieved by including a simple extraction step prior to assay. Many highly cross reacting antisera can be used in screening procedures, e . g . , drug abuse screening programmes, and such antisera have been used successfully in combined HPLC - RIA techniques where the immunoassay is used as an extremely sensitive detection system. Antisera raised by conventional means, i e . , by active immunisation of experimental animals, are polyclonal in nature and are a mixture of antibodies with heterogeneous specificity and avidity. In contrast, monoclonal antibodies raised using hybridoma techniques are homogeneous because the specificity is restricted to a single antigenic determinant.Although monoclonal antibodies are proving to be of enormous value in the analysis of complex systems and as diagnostic tools, their use in routine immunoassays has not yet been properly evaluated. Labels The sensitivity of a particular immunoassay depends, to a large extent, on the type and amount of label used. Exquisitely low assay sensitivity can be achieved using high specific activity labels. Tritium and 1251 have been the most commonly used radiolabels. Tritiated labels are generally stable, and the incorporation of the radioisotope causes little change in immunoreactivity , but such labels are not always available and have the great practical disadvantage that they require liquid scintillation counting.Iodine-125 labelled compounds have been widely used and although they are easily counted and are of high specific activity, their use is associated with a number of disadvantages. The half-life of 1251 is only 60 d and new batches of label must be prepared at frequent intervals. The incorporation of an iodine molecule, especially into small molecules, can cause dramatic changes in immunoreactivity . Many small molecules, which cannot be directly radioiodinated, can be “tagged” with a tyrosine or histidine containing residue, but this often reduces (or abolishes) antibody recognition and hence assay sensitivity.May, 1984 LOW LEVEL ORGANIC CONTAMINATION OF WATER 179 Other types of label have been introduced to overcome the disadvantages associated with the use ot radiolabels, e.g., disposal of radioactive waste and the potential health hazard of frequent radioiodination procedures.EIA is directly related to RIA in that the radiolabel is substituted by an enzyme label, and following phase separation the amount of enzyme in either the free or bound fraction is quantitated in the appropriate way. Other forms of EIA have also been developed. Enzyme-linked immunosorbent assay (ELISA) techniques4 have been widely applied to a range of substances and many kits are now available commercially. Enzyme assays are particularly suited to laboratories which are not already committed to RIA. They may also be suitable for field work in that a qualitative result as shown by a change of colour can be observed without sophisticated equipment.Alternative forms of label have been investigated. Fluorimetric labelling is relatively inexpensive, results in stable products and can be applied widely in immunoassays. FIA techniques are similar to those used in conventional RIA but homogeneous assays, requiring no separation phase, have been described. In fluorescence quenching methods, for example, the fluorescence of the label is quenched when bound to an antibody.5 FIA techniques have not yet fulfilled their promise in clinical chemistry because in many instances endogeneous fluorescence from serum components has reduced the sensitivity of the assay. This limitation may not apply in the analysis of water. Chemiluminescent immunoassays (CLIA) are currently being evaluated and have the potential to be extremely sensitive.6 Application of Immunoassays to Water Analysis Immunoassays, especially RIA and CLIA techniques, are capable of detecting concentrations of analytes as low as 10-10 M.Such techniques are therefore ideally suited to the analysis of microcontaminants in water where concentrations of analytes are expected to be very low (<< 1 pg 1-l). In clinical chemistry the sample volume is often a critical factor, but no such limitations exist in the analysis of water. The limit of detection of a particular assay can be increased by sample concentration prior to assay. Sample concentration can be easily achieved by evaporation or lyophilisation, followed by re-dissolution in assay buffer.Most assays are tolerant of changes in ionic strength and are probably less affected by such changes than by changes in protein concentration (which often occur in the clinical situation). Immunoassays for methotrexate, a potent anti-cancer drug, progesterone, norethisterone and ethinyl oestradiol (oral contraceptives), have been successfully adapted to the analysis of water. A concentration by lyophilisation step was included in the assays with resultant detection limits of between 5 and 10 ng 1-1.7 References 1. 2. 3. 4. 5. 6. 7. Yalow, R. S., and Berson, S. A . , J. Clin. Invest., 1960, 39, 1157. Ekins, R., in Voller, A., Bartlett, A., and Bidwell, D., Editors, “Immunoassays for the ~ O S , ” MTP Press Bolton, A. E., in Voller, A . , Bartlett, A., and Bidwell, D., Editors, “Immunoassays for the ~ O S , ” MTP Press Voller, A., Bartlett, A., and Bidwell, D. E., I .Clin. Pathol., 1978, 31, 507. Shaw, E. J., Watson, R. A. A., Landon, J., and Smith, D. S., J. Clin. Pathol., 1977,30, 526. Whitehead, T. P., Kricka, L. J., Carter, T. J. N., and Thorpe, G. H. G., Clin. Chem., 1979, 25, 1531. Aherne, G. W., and English, J., to be published. Ltd., Lancaster, 1981, p. 5. Ltd., Lancaster, 1981, p. 69. The Application of Pre-concentration and GC - MS Techniques to the Analysis of Water Sam ples-Pro blems and Sign if icance S. P. Scott, N. Sutherland and R. J. Vincent Water Services, Thames Water Authority, Directorate of Scientific Services, New River Head Laboratories, 177 Rosebery Avenue, London, EClR 4TP There is an ever-increasing awareness of low-level contamination of water by organic compounds.Recent review papers’%* set out an impressive array of information derived from analytical studies. The technique of combined gas chromatography - mass spectrometry (GC - MS) has played a very important part in facilitating this increase; several hundred compounds have been tentatively identified in drinking waters with the list extended by several hundred more when raw and waste waters are considered.3180 LOW LEVEL ORGANIC CONTAMINATION OF WATER Anal. Proc., Vol. 21 Thames Water has had its own GC - MS facility since 1981. The emphasis of the work undertaken so far has been in the building up of an essentially qualitative picture of the trace organics present in drinking water derived from river sources.Well over one hundred different organic compounds have been tentatively identified, generally at concentrations roughly in the range up to 0.1 pg 1-1. The limitations of GC - MS must be recognised. They are: first, only compounds that can be extracted by some means from water samples ready for injection into the GC can be studied; and secondly, the scope of the analysis is restricted to those compounds which are sufficiently volatile, or which can be made so by derivatization, to pass through the GC column. This presentation deals with aspects of the first of these limitations. Methods In our laboratories, three distinct methods of extraction are employed, These are: liquid - liquid extraction; resin adsorption; and closed loop stripping analysis (CLSA).For liquid - liquid extraction the solvent is dichloromethane (DCM), which has the advantages of relatively low toxicity and non-inflammability to add to its properties as a relatively non-polar solvent capable of extracting a wide range of organic compounds from water. Two-litre water samples are collected in glass bottles fitted with PTFE screw caps that have been cleaned with chromic acid. To the sample in its bottle is added 100 ml of DCM and the mixture is stirred magnetically overnight. A “cocktail” of several deuterium- labelled surrogate standards4 is added prior to extraction in order to assess the efficiency of the process. At the end of extraction the DCM is separated from the water prior to concentration. Resin adsorption consists in passing the water sample through a specially selected and prepared bed of resin that is capable of adsorbing a wide range of organic compounds from the aqueous phase.This technique came into widespread use as a result of the activities of Junk et al.5 and has usually emloyed XAD-2, XAD-4 or XAD-8 macroreticular resins, made of a styrene - divinylbenzene copolymer. Typically, a sample volume of between 2 and 20 1 is passed through a resin bed of about 20 ml volume contained in a 15 mm diameter chromatography column. We have found it preferable to suck the water through by means of a reciprocating pump at a rate of 20 ml min-1 in the interests of good, reproducible recoveries and of avoiding (by virtue of the suction) any possible contamination of the water sample before extraction.Adsorbed organic compounds are then eluted from the resin bed with two 15 ml and one 30 ml portions of diethyl ether. The eluates are combined prior to concentration. As in liquid - liquid extraction, a cocktail of deuterium labelled standards is added to the water sample before extraction to give a concentration of approximately 250 ng 1-1 of each compound. Concentration of the extract, whether from liquid - liquid or resin adsorption extractions, is carried out in a Kuderna-Danish evaporator apparatus fitted with a three-ball Snyder column to minimise the loss of volatile components, after drying the extract, first by freezing out the bulk of the water and then by passing the extract through a small column filled with anhydrous sodium sulphate (previously heated to 400 “C in order to remove any organic impurities). The extract is reduced in volume to about 2 ml (contained in the detachable graduated tube of the apparatus) and then further reduced in volume to 0.5 ml under a stream of dry nitrogen.The final extract, corresponding to a four thousand-fold concentration of a 2-1 sample, is examined by GC - MS using a VG Micromass 7035 mass spectrometer interfaced to a Dani 3800 capillary gas chromatograph. On-column injection of one or two rnicrolitres of extract to a 50 m fused silica column coated with OV-1 is employed and the mass spectrometer is operated at low resolution using 70 eV electron impact ionisation for most purposes. A typical GC - MS run will occupy about 1 h, involving a GC temperature programme from 25 to 250 “C at 4 “C min-1 and an MS cycle time of 1.4 s.A third technique for the extraction and concentration of the more volatile organic compounds that is enjoying increased popularity is closed loop stripping analysis (CLSA). This technique was pioneered by Grob6 and has the attraction of combining extraction and concentration in one operation. Its basis is the purging of volatile organic compounds from, typically, 1 1 of sample by recirculating the headspace above the sample through a small trap containing 1-5 mg of granular activated carbon. The organic compounds are adsorbed thereon and can be eluted with about 20 pl of carbon disulphide to yield, ready for injection to the GC - MS, a concentrate representing a concentration factor of 40 000 for the compounds that are amenable to purging and adsorption.The advantages of speed and freedom from the possible contamination offered by this technique are to an extent offset by its restricted scope .7May, 1984 LOW LEVEL ORGANIC CONTAMINATION OF WATER 181 Problems Having outlined the techniques of extraction and concentration, we can now report some of the problems that we have encountered. Inherent in the resin adsorption technique is the need to obtain resin free from organic contaminants. Some suppliers offer specially-purified grades of XAD resins and elaborate procedures for resin clean-up in the laboratory are described in the literature5 involving sequential Soxhlet extraction with a variety of solvents. Notwithstanding the application of these techniques, it became apparent that a large part of the total ion current (TIC) response in samples analysed using resin adsorption was due to artefact formation. Fig.1 shows TIC traces from: (a), an ether eluate of a resin bed left steeping in about 20 ml of high-purity water overnight; (b), a concentrate of the ether used for elution; and (c) an ether eluate of a resin bed through which had been passed 20 1 of high purity water. It can be seen that many of the peaks in trace (a) are present at much the same level in trace (b) and that trace (c) shows very little enhancement of the response in trace (a) even though about one thousand times more water is involved. This led us to conclude that a very significant contribution to over-all artefact levels arises from the mere interaction of water and resin if, as directed in the literature procedure,S the resin bed is prepared as a methanol slurry and used immediately thereafter for water extraction.Elution of the bed with diethyl ether immediately before water extraction much reduces the artefact contribution from the resin; it is thought that the heat of solution of methanol in water causes resin bead rupture, thus releasing artefacts.8 lo( 101 +4 E 1 C 0 Q .- - w I-" I 101 4 1 200 Scan number Fig. 1. XAD 4/XAD 8 resin adsorption: TIC traces of diethyl ether eluates (after concentration). ( a ) , Resin bed steeped in about 20 ml of high purity water; ( b ) , diethyl ether blank; ( c ) , 20 1 of high purity water passed through resin bed. We have found it necessary to re-distil diethyl ether immediately before use and, moreover, to analyse the concentrate with a minimum of delay.Diethyl ether left standing for more than a few days will form compounds which obscure the extract chromatogram and which have mass spectra similar to182 LOW LEVEL ORGANIC CONTAMINATION OF WATER Anal. Proc., Vol. 21 that of ethyl acetate. An ion at mlz 61 is characteristic of these interfering compounds. Fig. 2 shows: (a), the TIC trace from a resin adsorption concentrate left standing for 2 months; and ( b ) , a mass chromatogram for mlz 61 run on the same concentrate. Several of the large peaks in the TIC are thus shown to be associated with the ether impurities. L 200 400 600 800 1000 1200 Scan number 0:1 4:47 9:318 14:14 18:57 23:49 28:24 Retention time/min Fig.2. (a), TIC trace of diethyl ether eluate (after concentration) stored for about 2 months; (b), rnlz 61 mass chromatogram of the same, to show ether impurity peaks. With careful attention to detail, these problems with the resin adsorption technique can be contained within acceptable limits. However, it was largely problems such as these that prompted a change to liquid - liquid extraction for most routine purposes, although this technique was found not to be entirely trouble-free. It was found that all TIC traces, irrespective of the nature of the sample, were characterised by a complicated array of peaks eluting between 12 and 20 min into the run. Their mass spectra showed them to be alkyl benzenes, with chain lengths of up to four carbons, and various alkane fragments. These are characteristic of petroleum.The problem was found not to occur when samples were extracted in more rural surroundings, leading us to accept this state of affairs as a consequence of our urban situation. Re-distillation of the solvent immediately prior to use tended, if anything, to exacerbate the problem so we now rely upon commercially-available glass-distilled dichloromethane without further “purification.” A more serious problem was encountered when samples of treated water containing a chlorine residual of about 0.4 mg 1-1 were analysed. TIC chromatograms showed large peaks in the early part of the run. Some were attributable to the solvent blank, but others gave mass spectra characteristic of halogenated methyl butenes (with mlz 69 a prominent ion) and of haloethers.Such compounds, if present in treated water, would be a cause for some concern on account of their toxicity. Further investigation showed that these compounds were absent from the chromatogram when the samples were treated with sodium thiosulphate prior to extraction in order to destroy residual chlorine. A chloromethyl butene spiked into a thiosulphate-treated sample was, however, recovered, thus removing any anxiety that dechlorination was also destroying these halogenated organic compounds. It appeared that reaction between residual chlorine in the sample and dichloromethane (or impurities therein) was responsible for the formation of these compounds. In order to verify this possibility, closed loop stripping analysis (CLSA) was employed on the same treated water sample with and without prior dechlorination.None of the compounds were found in either sample. However, if 1 ml of dichloromethane was added to the residual chlorine-containing sample (1 1) prior to CLSA183 May, 1984 LOW LEVEL ORGANIC CONTAMINATION OF WATER extraction, a TIC chromatogram very similar to that obtained with DCM extraction of a residual-containing sample was produced, characterised again by the halogenated methylbutenes. Fig. 3 summarises these findings. I *-. 2 3 C - 100 c I- 0 0 200 280 360 440' 5:6 6:12 7:18 8:30 9:3510:4011:49 13:2 14:915:13 16:18 Scan number Retention time/min Fig. 3. (a), TIC trace of a DCM extract of a water sample containing residual chlorine; ( h ) , TIC trace of a CLSA extract of the same sample; (c), TIC trace of a CLSA extract of the same sample with 1 ml 1-1 of DCM added.TABLE I CHEMICALS CONSIDERED TO BE ARTEFACTS OF THE METHOD OF SEPARATION - ANALYSIS Chemical Methyl dichloroethanoate 2,3-Dichloro-2-methylbutane Diethenylbenzene Do d e c a n e Ethenyiethylbenzene 2-Ethoxypropane 3-Ethyl-4-methyl- furan-2,5-dione Ethylnaphthalenes Hexane Hex-1-ene 1-Methyl-1H-indene Met hy lnap ht halenes 2-Methylpentane l,l,l-Trichloro- propan-2-one I ,1,3-Trichloro- propan-2-one Undecane Thought to be derived from: ? Predicted to be noxious ? Predicted to be noxious XAD resin Used as a cross linking agent for vinyl polymers XAD resin XAD resin Propan-2-one or diethyl ether Tobacco smoke Remarks XAD resin or tobacco smoke Diethyl ether Diethyl ether XAD resin XAD resin Diethyl ether May arise from chlorination of propan-2-one added during spiking with deuterated standards May arise from chlorination of propan-2-one added during spiking with deuterated standards XAD resin184 EQUIPMENT NEWS Anal.Proc., Vol. 21 Discussion These experiences all illustrate the hazards from artefacts inherent in the analysis of trace organic compounds in water samples. A further illustration can be drawn from the outcome of the scrutiny of the results of an early GC - MS analysis (using resin adsorption) by Thames Water’s Catchment Quality unit; out of 107 compounds tentatively identified in a treated water sample, 16 were considered, upon investigation of the chemical and toxicological literature, to be artefacts of the analysis. Table I summarises this investigation. We offer the following advice as a result of our experiences: ensure the highest quality of reagents; always run a method blank; be aware of the sample’s history (e.g., its origins, method of collection and storage and its extraction); consider alternative extraction methods as an aid to the confirmation of validity; assess the environmental significance of the compounds tentatively identified and be alert to the possibility of artefacts in the method. The authors acknowledge the assistance and encouragement of Mr. M. L. Richardson (Scientist, Catchment Quality, Thames Water) and of the advice of the Water Research Centre, Stevenage and Medmenham laboratories. This summary is published with the permission of Dr. M. C . Dart, Director of Scientific Services, Thames Water. 1. 2. 3. 4. 5 . 6. 7. 8. References Bedding, N. D., McIntyre, A. E., Perry, R., and Lester, J. N., Sci. Total Envirun., 1982, 25, 143. Bedding, N. D., McIntyre, A. E., Perry, R., and Lester, J. N., Sci. Total Environ., 1983, 26, 225. Kraybill, H. F., J . Am. Water Works Assoc., 1981,73, 370. James, H. A., Fielding, M., Gibson, T. M., and Steel, C. P., Adv. Mass Spectrom., 1980,8, 1429. Junk, G. A., Richard, J. J., Grieser, M. D., Witziak, D., Witziak, J. L., Arguello, M. D., Vick, R., Svec, Grob, K., J. Chrumatogr., 1973, 84,255. Melton, R. G., Coleman, W. E., Slater, R. W., Kopfler, F. C., Allen, W. K., Avrand, T. K., Mitchell, D. E., Voto, S. J., Lucas, S. V., and Watson, S. C., in Keith, L. H., Editor, “Advances in the Identification and Analysis of Organic Pollutants in Water,” Volume 2, Ann Arbor Science, Ann Arbor, MI, USA, 1981, chapter 36. H. J., Fritz, J. S., and Calder, G. V., J. Chrumafugr., 1974, 99, 745. Water Research Centre, Medmenham Laboratory, private communication.

ISSN:0144-557X    

DOI:10.1039/AP9842100172

出版商:RSC    

年代:1984

数据来源: RSC

摘要:

184 EQUIPMENT NEWS Anal. Proc., Vol. 21 Equipment News Radiation Monitors A range of lightweight, pocket-sized radiation monitors is available. The PRI 91 has digital indication of ranges of 0-10,0-100 and 0-1 000 mrad h-1, with a resolution of 0.05 mrad h-1 at low field strengths. The PRI 93 has analogue indication and an additional range of 0-1 mrad h-1. An intrinsically safe version of the digital monitor, the PRI 90, is also available. ICI PLC, Physics and Radioisotope Services, P.O. Box 1, Billingham, Cleveland, TS23 1LB. Mass Analyser System Designed for use in combustion, plasma and molecular beam studies, the MMA 150 operates in conjunction with the maker’s QMC 511 quadrupole mass spec- trometer. It is especially useful in the analysis and measurement of neutral particles: radicals, unstable molecules, condensable species and reactive or excited particles, for example, which recombine after collisions with the walls of a chamber or with other gas molecules.Balzers High Vacuum Ltd., Northbridge Road, Berkhamsted, Hertfordshire, HP4 1EN. Spectrometry Software Software is available from Bausch and Lomb which enables automatic control of the Spectronic 2000 double beam scanning spectrophotometer through a number of popular microcomputers. Gallenkamp, P.O. Box 290, Technic0 House, Christopher Street, London, EC2P 2ER. Reflectometry Attachment An attachment, the RTA 2000, is available for the Shimadzu MPS 2000 ultraviolet - visible microproces- sor controlled recording spectrophotometer. Incorpor- ating both specular and integrating sphere reflectance capabilities in the wavelength range 240-800 nm, it can be used to increase both reflectance and transmission.V. A. Howe & Co. Ltd., 12-14 St. Ann’s Crescent, London, SW18 2LS. Atomic Absorption Accessory The PU 9060 continuous-flow vapour system is designed for use with the maker’s PU9000 and SP9 atomic- absorption spectrophotometers. Because a steady-state signal is produced rather than the transient signals obtained with conventional hydride systems, measure- ments can be acquired by conventional integration. Pye Unicam Ltd., York Street, Cambridge, CB12PX.May, 1984 EQUIPMENT NEWS 185 Sulphur Analyser The SLFA 920 is a non-dispersive fluorescent X-ray analyser. It has a lower detection limit to 20 p.p.m. and an upper limit of 5% mlm of sulphur.Repeatability at 1% mlm is 15 p.p.m. There is no radioactive source. Horiba Instruments Ltd., 5 Harrowden Road, Brack- mills, Northampton, NN4 OEB. Capillary Cells Ultra-low volume flow-through capillary cells for liquid and gas chromatography have a gold plated 3 mm bore and lengths of 5 or 10 cm with volumes of 0.35 and 0.7 cm3. They can be used in most spectrophotometers with approximately 4 x beam condensers. Harrick Scientific Corporation, 88 Broadway, P.O. Box 351, Ossining, NY, USA. Colorimeter The PCOl digital instrument offers three measurement modes. These include: transmittance from 0 to 100% to a resolution of 0.1%; absorbance, which is electronic- ally linearised, from 0 to 1.999 to a resolution of 0.001; and two concentration ranges electronically linearised to provide coarse and fine measurements over the absorbance readings. Jenway Ltd., Gransmore Green, Felsted, Dunmow, Essex, CM6 3LB.Gas Chromatograph The HP5890A is supported by a guaranteed uptime service covering a normal working day, Monday to Friday. The agreement allows for free service should the uptime fall below 99% during the contract period. Hewlett-Packard Ltd., Nine Mile Ride, Wokingham, Berkshire, R G l l 3LL. Automatic Sampler The Shimadzu AOC-9, developed for use with the maker’s GC-9A gas chromatograph, is a pneumatically operated syringe type instrument capable of handling up to 50 sample vials. No external supply of gas is required. Dyson Instruments Ltd., Sunderland House, Station Road, Hetton, Houghton-le-Spring, Tyne & Wear, DH5 OAT. Gas Chromatograph The Siemens SiChromat oven mantle lowers to give free access from three sides for insertion and exchange of columns.It opens and closes according to the power requirements of the oven and takes all internal and external temperature influences into account, giving short cooling periods. V. A. Howe & Co. Ltd., 12-14 St. Ann’s Crescent, London, SW18 2LS. HPLC Columns and Bonded Phases A range of columns containing Bakerbond materials bonded to 5 pm spherical silica gel with a pore diameter of 6 nm is available. A range of wide pore columns with a pore diameter of 33 nm has also been introduced. The Bakerbond phases are also available separately with 5, 10 and 40 pm particle sizes. Two types of chiral column, ionically bound DNBPG and covalently bound DNBPG, are also introduced.J. T. Baker Chemicals B.V., P.O. Box 1, Deventer, The Netherlands. Software for Gel Permeation Chromatography The GPC5 package, designed for use with the maker’s Model 3600 data station, allows computer processing, display and calculation of calibration curves and relative molecular mass distributions. Perkin-Elmer Ltd., Post Office Lane, Beaconsfield, Buckinghamshire, HP9 10A. Vitreous Silica Bonded Phase Columns Two columns, 12 m long with an i.d. of 0.1 mm and a film thickness of 0.1 pm, are available. One is coated with BP-1, a dimethyl silicone equivalent to SE-30 and OV-1; the other is coated with BP-10, a 7% cyanopropyl - 7% methyl silicone equivalent to Scientific Glass Engineering (UK) Ltd., Potters OV-1701.Lane, Kiln Farm, Milton Keynes, MKll 3LA. pH Measurement A range of Radiometer and Microelectrodes electrodes is available, together with a range of Radiometer pH meters. These include the ion analysing ION 85, which offers direct potentiometry where the concentration of an unknown is determined after calibration with stan- dard solutions, or the determination of ion concentra- tion by the standard addition, analyte addition or Gran’s plot techniques. V. A. Howe & Co. Ltd., 12-14 St. Ann’s Crescent, London, SW18 2LS. Micro Impinger This impinger allows a low flow-rate between 50 and 200 cm3 min-1. The chemical hazards are analysed according to NIOSH/OSHA methods. SKC Ltd., Hamworthy Trading Estate, Dawkins Road, Poole, Dorset, BH15 4JW. Water Test Kits Three types of kit are availabIe: Chemets, using a simple colorimetric test for visual comparison with supplied colour standards; Vacu-vials, which give a colorimetric test using a spectrophotometer such as the Bausch and Lomb Mini 20 and Spectronic 20 Models; and Titrets,186 EQUIPMENT NEWS Anal.Proc., Vol. 21 which have titration cells with graduations in p.p.m. Pipetting Devices The Pipetus is an electrically operated device for the topher Street, London, EC2P 2ER. safe pipetting of liquids. Any standard pipette between Air Samplers A range of instruments is available to cover specific requirements such as low noise level, prolonged sampling periods and mains operation with automatic time control. Gallenkamp, P.O. Box 290, Technico House, Chris- Semat Technical (UK) Ltd., 223 Hatfield Road, St. Albans, Hertfordshire, AL1 4UN.Autodiluter This device is designed for routine liquid handling procedures. Any sample size from 5 to 500 pl can be programmed from a touch key pad, together with reagent volumes of 5 pl to 5 ml. It can perform eight different functions. Gallenkamp, P. 0. Box 290, Technico House, Christopher Street, London, EC2P 2ER. Powder Sampler This instrument, which operates on the spinning riffler principle, provides up to 16 statistically representative samples from 1 1 of bulk powder. Coulter Electronics, Ltd., Northwell Drive, Luton, Bedfordshire, LU3 3RH. Multi-functional Weighing LabPac consists of a GE305 application input device and four programme keys for the following applications: net total, per cent.determination and percentage weighings, animal weighing, mean value and standard deviations and result indications in non-metric units. LabPac converts standard laboratory balances into multi-functional balances. Mettler Instrumente AG, CH-8606 Griefensee, Swit- zerland. Balances A wide range of Shimadzu electronic standard and multi-functional balances are available. The range includes the EB280 and EB2800 dual range balances, the EB50, EB500 and EB5000 single range models, and the ED56K and ED28K heavyweight balances. There are also two AEL160 series high precision units, several dedicated models and the Fortec series of check weighing systems. V. A. Howe and Co. Ltd., 12-14 St. Ann's Crescent, London, SW18 2LS. 0.1 and 100 ml can be used.Filling and emptying is push-button controlled. Camlab Ltd., Nuffield Road, Cambridge, CB4 1TH. Microcarrier Stirrers A range of Techne microcarrier stirrers is available. Four models are included: the lOlL takes one vessel of 3 or 5 1, the 102L takes two vessels of up to 1 1 each, the 104s will carry up to four vessels each of 500 ml and the 104L can carry four vessels up to 1 1. A softstart feature prevents turbulence on start-up. Gallenkamp, P.O. Box 290, Technico House, Chris- topher Street, London, EC2P 2ER. Gas Dividers Four models are available offering flow-rates to between 0.2 and 5 1 min-1. Horiba Instruments Ltd., 5 Harrowden Road, Brack- mills, Northampton, "4 OEB. Chamber Furnaces The ECF family of programmable chamber furnaces offers four chamber sizes and a maximum operational working temperature of 1200 "C.Lenton Thermal Designs Ltd., 12/14 Fairfield Road, Market Harborough, Leicestershire, LE16 9QQ. Cryostats A range of four microtome cryostats from Bright Instruments is available. A rotary retracting microtome will produce sections as thin as 0.2 pm. The tempera- ture is digitally displayed and a quick freezer is provided for reaching temperatures 5-10 "C below ambient. Gallenkamp, P.O. Box 290, Technico House, Chris- topher Street, London, EC2P 2ER. Microscope The Polyvar-Pol is a wide field polarising instrument for use with incident and transmitted light. It has a rotary stage and a Bertrand module for rapid qualitative and quantitative investigation of polished thin sections. Reichert-Jung UK, 820 Yeovil Road, Slough, SL1 4JB.May, 1984 THEOPHILUS REDWOOD LECTURE 187 Literature A catalogue covers a range of HPLC valves, fittings and accessories. Scientific Glass Engineering (UK) Ltd., Potters Lane, Kiln Farm, Milton Keynes, MKll 3LA.A brochure describes the Wescan range of single column ion chromatography instrumentation. Included are details of the new ICM-11, which incorporates an electrochemical detector in addition to the standard conductivity detector. Also described is the new Versa Pump-11, which features a 10 ml min-1 flow at pressures up to 5 lb in-2. Techmation Ltd., 58 Edgware Way, Edgware, Middlesex, HA8 8JP. A newsletter, Wescan Ion Analyser Number 6, contains articles on transition metal analysis, the analysis of anti-freeze and engine coolant, the optimisation of eluent selectivity in cation analysis, the analysis of etching baths and other topics.Details are given of the Wescan high speed cation column. Techmation Ltd., 58 Edgware Way, Edgware, Middlesex, HA8 8JP. A brochure covers a range of water test kits and pH indicator papers. It includes an article on pH and ion measurement. Camlab Ltd., Nuffield Road, Cambridge, CB4 1TH. A series of leaflets describes a range of Sauter analytical and precision balances and their applications. MSE Scientific Instruments, Manor Royal, Crawley, West Sussex, RHlO 2QQ. A brochure gives details of particle size analysers. Bedfordshire, LU3 3RH. Coulter Electronics Ltd., Northwell Drive, Luton, A brochure covers the full range of Haake baths and circulators, which cover a temperature range from -90 to +300 “C. Included are details of the F4 and N4 temperature controllers, which have removable control heads so that the temperature control unit can be mounted remote from the bath. Gallenkamp, P.O. Box 290, Technico House, Chris- topher Street, London, EC2P 2ER. A brochure gives details of a range of fluids from Haake for use in temperature baths and circulators. Gallenkamp, P.O. Box 290, Technico House, Chris- topher Street, London, EC2P 2ER. Theophilus Redwood Lecture At its meeting on December 7th, the Council of the Analytical Division, on recommendation of its Honours Committee, agreed that the 14th (1985) Theophilus Redwood Lecture should be given by Professor Dr. M. Grasserbauer, Director of the Insti- tute for Analytical Chemistry of the Technical Univer- sity, Vienna. A booklet, “Get the Right Membrane for Every Job,” carries an introduction on membrane filter selection followed by items on microbiological testing, gravi- metric chemical and biochemical methods, macroscopic and/or microscopic examination, concentration, ultra- filtration, particle removal and sterilising filtration. Semat UK Ltd., 223 Hatfield Road, St. Albans, Hertfordshire, AL1 4UN.

ISSN:0144-557X    

DOI:10.1039/AP9842100184

出版商:RSC    

年代:1984

数据来源: RSC

摘要:

May, 1984 THEOPHILUS REDWOOD LECTURE 187 Conferences and Meetings Hewlett-Packard Analytical Symposium June 11-13, 1984, Stratford-upon-Avon An analytical symposium, organised by Hewlett- Packard Limited, will take place at the Moat House International Hotel, Stratford-upon-Avon. The event combines a scientific programme devoted to liquid chromatography, gas chromatography and mass spec- trometry, with an exhibition of Hewlett-Packard analy- tical instrumentation. In order to ensure that the lecture programme is of a high scientific standard, HP have invited the following speakers: Professor Jack Henion (Cornell University); Professor Milton Lee (Brigham Young University); Dr. Konrad Grob (Kantonales Labor, Zurich, Switzerland); Dr. D. E. Games (Uni- versity College, Cardiff); and Dr.Hugh Scott (Heriot- Watt University). For registration information please contact Mrs. Eileen Brewster, Hewlett-Packard Limited, Analytical Instrumentation Group, King Street Lane, Winnersh, Wokingham, Berkshire, RGll5AR. Quality and Acceptance Testing of Packaging-with Reference to Foods, Beverages, Pharmaceuticals and Cosmetics June 21-22, 1984, St. Andrews A symposium with the above title has been organised jointly by the Automatic Methods Group and the Scottish Region of the Analytical Division of the RSC. It is being held in the congenial surroundings of the University of St. Andrews. The symposium is particu- larly aimed at managers, scientists and technicians who wish to be aware of the legal and other requirements for quality of packaging and packaging components, and to understand some of the problems involved from both the producer’s and user’s viewpoints, with the emphasis being placed on the areas of foods, beverages, phar- maceuticals and cosmetics.Some 19 papers are being presented over the 2 days in five sessions. Each session has a particular theme and extended discussion periods are scheduled at the end of each session. The themes covered are: Legal Require- ments for Quality of Packaging Materials; Novel Packaging Materials and their Acceptance Testing; Quality and Acceptance Testing of Glass and Metallic Packaging Materials; Quality and Acceptance of Plastic188 CONFERENCES AND MEETINGS Anal. Proc., Vol. 21 Materials; Quality and Acceptance Testing of Papers and Coated Papers. A small instrument exhibition is also scheduled.The symposium is residential, with accommodation being available from Wednesday, June 20, to Saturday, June 23, in the Andrew Melville Hall at the University. A full social programme is being arranged to comple- ment the scientific sessions. This will include an informal reception on the evening of June 20, a Symposium Dinner on June 21 and a Golf Tournament over the St. Andrews New Course followed by a Tournament Dinner, at which prizes will be presented for the best rounds of the day, on June 22. The registration fee is 240 for members and f60 for non-members of the RSC; the 2-day accommodation charge, including the symposium dinner is f45. Further details and registration forms are available from Dr. C. J. Jackson, Honorary Secretary AD Automatic Methods Group, Health & Safety Execu- tive, Occupational Hygiene Laboratory, 403 Edgware Road, London, NW2 6LN (Tel.01-450-8911, Ex. 227). Second Biennial National Atomic Spectroscopy Sympo- sium July 10-13, 1984, Lee& This symposium is organised jointly by the Atomic Spectroscopy Group of the Analytical Division of the Royal Society of Chemistry and the Spectroscopy Group of the Institute of Physics and this year will be held in the University of Leeds. The Plenary Lectures will be as follows: “Developments in ICP Atomic Spectroscopy,” by R. M. Barnes; “The Zeeman Effect in Analytical Atomic Spectroscopy,” by J. B. Dawson; “Recent Developments in the Instrumentation and Application of Energy Dispersive X-ray Spectrometry,” by D.E. Leydon; “Trace Metal Speciation by Coupled Chromatography - Atomic Spectroscopy,” by L. C. Ebdon; and “ICP-Emission Source, Ion Source or Atomiser?” by S. Greenfield. The invited lecturers will be K. Laqua, M. Thompson, W. Frech, N. J. Goddard, H. W. M. Webster, H. T. Delves, J. Tyson, D. L. Miles, J. M. Mermet and K. Paul. For further information contact Mr. F. Buckley, Department of Earth Sciences, University of Leeds, Leeds, West Yorkshire, LS2 9JT. International Symposium on Quantitative Luminescence Spectrometry in Biomedical Sciences September 3-6, 1984, Ghent, Belgium This symposium, which is to be sponsored by IUPAC, will be held in the Faculty of Pharmaceutical Sciences of the State University of Ghent. The Plenary Lecturers will be R. P. Ekins (The Middlesex Hospital Medical School, London), R.W. Frei (Free University of Amsterdam), G. G. Guilbault (University of New Orleans), J . N. Miller (Loughborough University of Technology) and J . S. Woodhead (University of Wales, Cardiff). In addition to the above, contributed papers and posters will be presented on: drug analysis and bioanalysis via fluorescence and phosphorescence (LTP, RTP, micellar); fluorescence and chemilumines- cence immunoassays; detection techniques in chromat- ography (fluorescence, RTPL) ; solid surface lumines: cence methods; chemical derivatisation methods; luminescence applications and drug metabolism; clin- ical chemistry; biochemistry; pharmacokinetics; toxi- cology; ecology; and protein tagging. For further information write to Dr.W. Baeyens, Symposium Chairman, Laboratoria voor Farmaceu- tische Chemie en Ontleding van Geneesmiddelen, Rijksuniversiteit Gent, Harelbekerstraat, 72, B-9000 Gent, Belgium. Analyticon 84 September 4-6, 1984, London The second in this series of conferences which are organised by the Scientific Instrument Manufacturers’ Association of Great Britain in association with the Royal Society of Chemistry and the Chromatography Discussion Group will be held at the Barbican Centre. The plenary and keynote lecturers in the various sessions are now known and are as follows. Computers in the Laboratory: Plenary Lecturers: Professor 0. L. Massart, “Chemometrics,” Professor T. S. Edmonds, “Computers in Laboratory Management”; Keynote Lecturers: Dr. D. Porter, “Robotics in Analytical Instrumentation,” Dr.J. A. Goldsmith, “The Role of Computers in Pharmaceutical Documentation”: Chro- matography: Plenary Lecturers: Professor 3 . H. Knox, “Some New Materials for Gas and Liquid Chromato- graphy-Their Physical and Chromatographic Proper- ties,” Dr. R. P. W. Scott, “Packed Columns-Capillary Columns: Their Relative Advantages;” Keynote Lec- turers: Dr. A. F . Fell, “Recent Advances in Rapid- scanning Photodiode Array Detection in HPLC,” Dr. J. R. Conder, “Large Scale Gas Chromatography- from Analysis to Production”: Molecular Characterisa- tion and Surface Analysis: Plenary Lecturers: Professor J. H. Beynon, Dr. R. N. Miller, “Thermal Wave Techniques for the Examination of Surfaces”: Elemen- tal Analysis: Plenary Lecturers: Professor J.Robin, Professor J. M. Ottaway; Keynote Lecturers: Dr. A. M. Ure, “Sample Preparation and Separation Methods in the Analysis of Environmental and Biological Materials by Atomic Spectrometry,” Dr. A. R. Date, “Induc- tively Coupled Plasma Source Mass Spectrometry”: Clinical Analysis and Biosciences: Invited Lecturers: Professor W. P. Collins, “Advances in Immunoassay Techniques,” Dr. A. McLelland, “The Impact of Microprocessors on Automation and Work Organisa- tion in the Clinical Laboratory,” Professor A. Atkinson, “Microbial Organisms as Sources of Reagents and Therapeutic Agents,” Dr. L. Haff, “Developments in Protein and Peptide Separations”: Electroanalytical Methods: Plenary Lecturer: Dr. J. D. R. Thomas, “Perspectives in Electroanalytical Chemistry”; Keynote Lecturers: Dr.C. A. Marsden, “Zn Vivo Electro- chemical Analysis,” Mr. R. Rooney, “Polarography- Applications and Sample Treatment.” For further information contact Mr. G. C. Young, SIMA, Leicester House, 8 Leicester Street, London, WC2H 7BN. Seventh Ceramic Chemists’ Conference October 8-10, 1984, Llandudno This conference will be held in the Hydro Hotel. Its theme will be the state of the Art in the CharacterisationMay, 1984 COURSES 189 of Ceramics and it will include papers of interest to The University of Texas at Austin, Austin, TX 78705, ceramists who use analysis as well as to the analyst USA. himself. For further information contact the Conference Secretary, Mr. R. A. Reed, British Ceramic Research Association Limited, Queens Road, Penkhull, Stoke on Trent, Staffordshire, ST4 7LQ.Twenty-third Eastern Analytical Symposium November 13-16, 1984, New York, NY, USA This series of symposia is sponsored by the American Chemical Society, the Society for Applied Spectroscopy and the American Microchemical Society. This year’s meeting will take place in the New York Penta Hotel and has been extended to four days (both the technical sessions and the exhibition). The technical session will include oral lecture and poster sessions, as well as exhibitor workshops. Topics for the technical sessions will include various aspects of HPLC, pharmaceutical analysis, computer assisted analytical techniques, mass spectroscopy, NMR, X-ray methods, chemometrics, forensic science, surface analysis, TLC, microscopy, lasers in analytical chemistry, analysis of precious metals, environmental analysis, capillary GC, ICP spectroscopy, molecular spectroscopy, atomic- absorption spectroscopy, electroanalytical techniques, food analysis, bioanalytical techniques, polymer charac- terisation, thermal analysis, laboratory automation, robotics and new software methods in analytical chemistry.Further information is available from Dr. S. David Klein, EAS Publicity Chairman, Merck and Co. Inc., P.O. Box 2000iR80L-106, Rahway, NJ 07065, USA. Flow Analysis 111-an International Conference on Flow An a I y s i s September 5-8, 1985, Birmingham This conference will be held in the Department of Chemistry, University of Birmingham; accommodation will be available in the University Halls of Residence. It will be organised by the Midlands Region of the Analytical Division of the Royal Society of Chemistry. The scope of the Conference will be similar to that of the Flow Analysis Conferences held in Amsterdam, 1979, and Lund, 1982, and will cover research on all aspects of continuous flow analysis. The scientific programme will consist of plenary and invited lectures, submitted research papers and posters, and working demonstra- tions. An exhibition of commercial equipment will be organized. For further information write to Flow Analysis 111, Dr. A. M. G. Macdonald, Department of Chemistry, The University, P.O. Box 363, Birmingham, B15 2TT. Chemistry and Resources of the Global Ocean September 22-28, 1985, Woods Hole, MA, USA This is a Chemrawn (Chemical Research Applied to World Needs) conference of IUPAC. It will review oceanic chemical processes, cycles and resources (both sea and seabed). The Chairman of the Organising Committee is Professor J . Robert Moore, Marine Science Institute,

ISSN:0144-557X    

DOI:10.1039/AP9842100187

出版商:RSC    

年代:1984

数据来源: RSC

摘要:

May, 1984 COURSES 189 Courses Advanced Capillary Gas Chromatography June 13-15, 1984, London This three-day course, organised by Chrompack, is designed to give delegates an in-depth understanding of the theory and operation of modern types of capillary column. It is particularly suitable for those who have previous experience in the subject or those who attended the Basic Capillary Gas Chromatography Course. Both the theoretical and the practical aspects of capillary columns will be covered. The fee for the course is f230 plus VAT. For further details of the course and its venue, and registration forms, please contact Chrompack UK Ltd., 61 Shrub- bery Road, London, SW16. 6th Summer School of Automatic Chemical Analysis July 1-6, 1984, Brighton This course will be held at the University of Sussex, Falmer.The key topics will be automation, computing, and laboratory management. Over the past 5 years the course has established a multi-purpose role; it enables analysts from a wide range of industries to acquire the basic skills needed for laboratory automation, while experienced users of automated systems can increase their knowledge and appreciation of the latest developments in the field. This year the Summer School will emphasise automated chemistry and contain less on computing. The proven format of an integrated series of lectures, tutorials and practical sessions will be retained. The emphasis on automated chemistry is reflected in both the lecture topics and the list of lecturers and tutors. New names in the latter include Professor R.Dessy from Virginia State Polytechnic, USA, and Professor J. Ruzicka from the Technical University of Denmark. A brochure giving the full list of lecturers and tutors and the lecture topics is available from Beverly Humphrey, Summer School of Automatic Chemical Analysis, 176a North View Road, London, N8 7NB. Analytical Plasma Emission Spectrometry July 5-6, 1984, Manchester A residential course on the above subject will be held at UMIST. The aim of the course will be to provide an extensive introduction to analytical plasma emission spectrometry for both potential users and existing users who wish to gain a better understanding of the technique. The course lecturers will be G. F. Kirk- bright, R. F. Browner, A. R. Date, 0. Dugdale, L. C. Ebdon, D. L. Miles, L. Ranson, R. D. Snook, R. Thomas, M. Thompson, G. Tyler, J. N. Walsh and S. J. Walton. The registration fee will be f90 (student rate f50), while accommodation will be 28.00 per night. For further details contact The Registrar, UMIST, P.O. Box 88, Manchester, M60 1QD.

ISSN:0144-557X    

DOI:10.1039/AP9842100189

出版商:RSC    

年代:1984

数据来源: RSC

摘要:

190 ANALYTICAL DIVISION DIARY Analytical Division Diary Anal. Proc., Vol. 21 MAY Wednesday, 23rd, 10.30 a.m.: Sunbury South East Region and Special Techniques Quantitative NMR. BP Research Centre, Sunbury. Contact: Mr. J. Huddleston, AERE, Building 10.2, Instrumentation and Applied Physics Division, Harwell, Oxfordshire, OX1 1 ORA. (Tel. 0235-24141, Ex. 2030). Group. Thursday, 24th: Birmingham Midlands Region, jointly with the Royal Statis- Statistics in Chemistry. The University, Birmingham. Contact: Mr. H. E. Brookes, 35 Dunster Road, West Bridgford, Nottingham, NG2 6JE. (Tel. 0602-231769). tical Society. JUNE Tuesday, Sth, 4 p.m.: London Analytical Division: Annual General Meeting (Revised date): 4 p.m. Retiring President’s Address: 4.15 p.m. Sauces Other Than ICPs. Speaker: Professor S.Greenfield. Scientific Societies Lecture Theatre, 23 Savile Row, London, W.l. Contact: Miss P. E. Hutchinson, Analytical Division, Royal Society of Chemistry, Bur- lington House, London, W1V OBN. (Tel. 01-734-9971). Wednesday, 6th, 10.30 a.m.: Gravesend South East Region and Electroanalytical Recent Developments in Water Analysis. “Power Station Water Analysis,” by K. Wall. “Adsorption Enhanced Polarography for Some Tran- sition Metal Ions,” by K. Torrance. “Dionex Ion-exchange Chromatographic Water Analysis at Trace Levels,” by D. Smith. “Modern Trends in Continuous Water Quality Moni- toring,” by R. Barnhoorn. “Problems in pH Measurement in Fresh Water,” by P. D. Whalley. “Recent Studies on the Measurement of Iron and Aluminium in Potable Water,” by P.Watson. CEGB, SE Region Scientific Services, Canal Group. Registration is necessary. Cost f10 to RSC members, f12 to non-members and f5 to bona fide students. Contact: Mr. A. E. Bottom, Kent Industrial Measurements Ltd., Oldends Lane, Stone- house, Gloucestershire, GLlO 3TA. (Tel. 0453-826661). Wednesday, 6th, 10.15 am.: Huntingdon East Anglia Region. Analytical Aspects of Biological Safety Evalua- tion. “GLP and Its Implications to the Analytical Labora- tory,” by A. Stavrou. “GLP-Problems Relating to the Split Site Situa- tion,” by P. Carter. “Mutagenicity of Complex Environmental Samples,” by E. Jones. “Analytical Techniques for the Determination of Veterinary Residues in Poultry Tissues,” by A. Hobson-Fro hock. “Use of Bonded Phase Sorbants for the Clean-up of Biological Samples,” by A.Calverley. “Determination of Blood Cyanide and Its Role in Producing Incapacitation in Fire Victims,” by D. Purser. Huntingdon Research Centre, Huntingdon . Registration is necessary. Cost f10 to RSC members, f15 to non-members and f5 to students and retired members. Contact: Mr. A. Anderson, Huntingdon Research Centre, Huntingdon, Cambridge- shire, PE18 6ES. Wednesday, 13th, 10.30 a.m.: London Particle Size Analysis Group. Application of Image Analysis to the Measure- ment of Particle Size and Shape. Keynote Talk by A. Flook. “The Use of Automatic Image Analysis in the Assessment of Particle and Grain Size Distribu- tions,” by Professor B. Ralph. “Measurement of the Particle Size Distribution of Hydroxy Ethyl Cellulose,” by S.P. Cooke. “The Location of Particle Edges in a Digitised Image from the Optical Microscope,” by L. Kenny. “Application of Optical Image Analysis to the Measurement of Porosity in Particulate Solids,” by C. McCourt and R. Jones. “Shape Analysis of Particle Perimeters Using Cur- vature,” by R. Beresford. “Image Analysis of Complex Microscope Samples,” by C. Taylor. “Contribution on Quantimet,” by A. Terrell. “Applications Illustrating the Benefits of Image Store,” by W. Boyle. Road, Gravesend. [continued on p . 191May, I984 ANALYTICAL DIVISION DIARY 191 Analytical Division Diary, continued June, continued Health and Safety Executive, Occupational Medicine and Hygiene Laboratories, 403 Edgware Road, London, NW2 6LN. Registration is necessary. Cost 515 to members of the Particle Size Analysis Group, f20 to non-members.Contact: Dr. A. Rood, Health and Safety Executive, Occupational Medicine and Hygiene Laboratories, 403 Edgware Road, London, NW2 6LN. (Tel. 01-450-8911). Friday to Sunday, 15th to 17th: Ironbridge North West Region: Summer Meeting. Friday, 15th- “Snakes and Ladders,” by F. Ridgway. Saturday, 16th- Tour of Ironbridge Gorge Museum. Sunday, 17th- Continued Tour of Ironbridge Gorge Museum. Telford Hotel, Golf and Country Club. Registration is necessary. Cost 269.50 per person. Contact: Mr. T. E. Hanley, 5 Old Hall Court, Ashton, Chester, Cheshire. (Tel. 0829- 5 1609). Thursday, 21st, 10.30 a.m.: London Microchemical Methods and Joint Pharma- Newer Techniques in Pharmaceutical Analysis. The meeting is to describe some newer tech- niques in pharmaceutical analysis, and to dis- cuss when, or if, they should be utilised in the Pharmacopoeias.“Identification of Impurities at the Sub-p.p.m. Level in Pharmaceuticals,” by D. S. Ashton. “Applications of New Detection Strategies in HPLC,” by Miss S. M. Selkirk and A. F. Fell. “Advances in HPLC Columns,” by C. Loscombe. “Ion Chromatography-One Year’s Experience at the Medicines Testing Laboratory,” by C. Stevens. “Newer Techniques in Pharmacopoeias-When Can They be Justified?” by C. A. Johnson. Pharmaceutical Society of Great Britain, 1 Lambeth High Street, London, S.E.l. Registration is necessary. Cost f15 to members of RSC and PSGB, $20 to non-members. Contact: JPAG Secretariat, Room 413, Phar- maceutical Society of Great Britain, 1 Lam- beth High Street, London, SE1 7JN.(Tel. ceutical Analysis Groups. 01-735-9141, EX. 289). Thursday and Friday, 21st and 22nd: St. Andrews Scottish Region and Automatic Methods Quality and Acceptance Testing of Packaging- With Reference to Foods, Beverages, Phar- maceuticals and Cosmetics. The symposium is particularly aimed at managers, scientists and technicians who wish to be aware of the legal and other requirements for quality of packag- ing and packaging components, and to under- stand some of the problems involved from both the producers and users viewpoint, the emphasis being placed in the area of foods, beverages, pharmaceuticals and cosmetics. Thursday, 21st- Session I: Legal Requirements for Quality of Packag- ing Materials. Keynote Lecture: “The Packaging of Food and Pharmaceutical Products-Legislation, Recom- mendations and Codes of Practice in Europe and the USA,” by D.Shorten. Group. “GMP-The Orange Guide,” by J. R. Sharp. Session 11: Novel Packaging Materials and their Acceptance Testing. “Recent Developments in Blister Packaging,” by R. Webb. “The Development and Acceptance Testing of the Wine BOX,” by C. M. Davis. “The Development and Acceptance Testing of Secure Packaging,” by J . H. Whyte. Session 111: Quality and Acceptance Testing of Glass and Metallic Packaging Materials. “The Selection of Surface Coating Materials for Cans,” by a speaker from Metal Box Co. PLC. “The Acceptability of Aluminium Kegs for Use in the Brewing Industry,” by a speaker from Alumasc Ltd. “Quality Control Requirements of Glass Packaging Materials,” by J . G.Ranshaw. “Testing of Glass Packaging Materials in the Phar- maceutical Industry,” by P. Rhodes. Friday, 22nd- Session IV: Quality and Acceptance Testing of Plastic Materials. “Plasticisers in Plastic Materials,” by D. Pugh. “Packaging Components and Acceptance Testing in the Pharmaceutical Industry,” by K. Harburn. “Identification of Plastic Films,” by J. L. Sharp. “NIR Technology Applied to Packaging Materials,” “Chemical and Physical Testing and Properties of “Analytical Pyrolysis of Packaging Materials,” by S. “Radiometric Determination of the Total Migration by G. Parnham. Polyethylene,” by Mr. McFarland. Jones. of Plastic Constituents,” by H. Reed. [continued on p . 192192 ANALYTICAL DIVISION DIARY Anal.Proc., Vol. 21 Analytical Division Diary, continued June, continued Session V: Quality and Acceptance Testing of Papers and Coated Papers. “The Application of Good Management Practice in the Production of Printed Packaging Components for the Pharmaceutical Industry,” by J. Viselle. “Physical and Regulatory Testing of Paper and Board Packaging Products,” by J. M. Chamberlin. Paper on quality and acceptance testing of coated paper products used in the food industry; title and author to be confirmed. Chemistry Department, St. Andrews Univer- sity? North Haugh, St. Andrews. Registration is necessary. Cost 240 to RSC members, 260 to non-members and f15 to bona fide students and retired members; additional charges for accommodation and Symposium Dinner. Contact: Dr.C . J. Jackson, Health and Safety Executive, Occupational Medicine and Hygiene Laboratory, 403 Edgware Road, London, NW2 6LN. (Tel. 01-450-8911, Ex. 227). Tuesday and Wednesday, 26th and 27th: Man- Chester Analytical Division. Research and Development Topics in Analytical Chemistry and First L. S. Theobald Lecture. Tuesday, 26th- “Direct Potentiometric Monitoring of Proteins,” by M. L. Hitchman, F. Nyasulu and A. Aziz. “Continum Source Atomic Absorption Spectrome- tric Analysis with Probe Atomisation,” by J. Carroll, D. Littlejohn, J. Marshall, J. M. Ottaway, J. M. Harnly and N. J. Miller-Ihli. “The Measurement and Significance of Nebulizer Suction in Flame AAS,” by C. E. O’Grady, I. Marr and M. S. Cresser. “Some Aspects of the Pyrolysis Gas Chromatography of Quaternary Phosphonium Compounds,” by Sarah J.Abraham and W. J. Criddle. “Applications of Immobilised Enzymes in Flow Injection Analysis,” by M. Massoom. “Metal Ions as Labels in Immunoassay,” by Nicola J. Wilmott, J. N. Miller and J. F. Tyson. “The Simultaneous Determination of Chloride, Bro- mide and Iodide by HPLC,” by P. E. Moss and W. I. Stephen. “Studies of Tin Oxide Semiconductors as Novel Gas Chromatographic Detectors,” by S. J. Rowley, L. Ebdon, M. M. Rhead and D. A. Leathard. L. S. Theobald Lecture: “Fire in Flight,” by Profes- sor E. Bishop. Poster Presentations “The Effect of Materials of Clinical Interest on Calcium Ion-selective Electrode Response,” by S. A. H. Khalil, G. J. MoodyandJ. D. R. Thomas. “Piezoelectric Quartz Crystal Detection of Ammo- nia,” by C.S.I.Lai, G. J. Moody and J. D. R. Thomas. “Solvent Extraction Studies of Meta1:Polyalkoxylate Complexes in Relation to Electrochemical Response,” by P. H. V. Alexander, G. J. Moody and J. D. R. Thomas. “Investigation of the pH Response of Carbon Fibre Electrodes,” by J. E. Morgan, V. J. Jennings and J. Lindley. “Rapid Analysis of Sugar Solutions,” by G. Adediran and L. S. Bark. “Ion-exchangers in Sea Water Analysis,” by M. N. Abunijam, E. Ichsan, T. H. Shah and F. Vernon. “The Determination of Immunoglobulins Using Flow Injection Analysis,” by A. Hughes and P. Wors- fold. “Kinetic Methods for Ruthenium Based on Bromate and Perbromate Oxidations,” by J. T. Ayodele, B. G. Cooksey and J. M. Ottaway. “Investigation of Working Conditions for Automatic Probe Atomisation in ETA-AAS,” by S.Cooke, D. Durie, D. Littlejohn, J. Marshall and J . M. Ottaway. “Applications of LESTEQ in Automatic Spectropho- tometric Titrimetry,” by G. J. Thomason, B. G. Cooksey and J. M. Ottaway. “Concentration Gradients for Calibration Purposes,” by J. M. H. Appleton and J. F. Tyson. “Drug - protein Binding Studied by New Flow Injection Analysis Methods,” by G. L. Abdullahi and J. N. Miller. “The Flame Atomisation of Molybdenum,” by L. L. Sarkissian and J. F. Tyson. “High Performance Liquid Chromatography of Organic and Inorganic Anions Using a Micellar Mobile Phase,” by G. F. Kirkbright and F. G. P. Mullins. “Chemically Sensitive Fibre Optic Instrumentation,” by A. J. Guthrie, G. F. Kirkbright and R. Narayanaswamy . “Photoacoustic Imaging for Non-destructive Test- ing,” by J.T. Jones, G. F. Kirkbright, R. M. Miller and A. Rzadkiewicz. “The Determination of Metal Salts Alone and in the Presence of Acids by Catalytic Thermometric and Combined Catalytic Thermometric - Turbidime- tric Titrimetry,” by M. Kashanipour and E. J. Greenhow. Wednesday, 27th- “An Automatic Gamma Counting System Involving a Robotic Arm for Decontamination Studies,” by N. R. Burgess and J. Huddleston. “Use of a Chromatographic Data Handling System Within a Pesticide Research Laboratory,” by Mrs. L. D. LeBorgne. [continued on p . 193May, 1984 ANALYTICAL DIVISION DIARY 193 Analytical Division Diary, continued June, continued “The Determination of Water in Crude Oil by Microwave Attenuation,” by J . F. Alder and I. M. Clegg. “Studies on Surface Anion Exchangers for Ion Chromatographic Determination ,” by S. J. Lyle and Miss C. H. G. Pearson. of Metals in Water by ESR,3y by B. D. Dalgarno. Renoid Building, UMIST, Manchester. Registration is necessary. Charge for accom- modation and meals only. “The Analysis of Ionic Species by HPLC,” by M. H. Gaffney and M. Cooke. “Flow Injection Analysis: a Pre-column Derivatisa- tion Method for Liquid Chromatography,” by Contact: Miss P. E. Hutchinson, Analytical Division, Royal Society of Chemistry, Bur- lington House, London, W1V OBN. (Tel. R. S. Rowles. 01-734-9971).

ISSN:0144-557X    

DOI:10.1039/AP9842100190

出版商:RSC    

年代:1984

数据来源: RSC