摘要:

Proceedinas - - - - ~of the Analytical Division 0.fThe Chemical Society175176176179182183188189190190193195196CONTENTSRobert Martin Caven, 1870-1 934Summaries of Papers'Electroanalysis in Industry''Plasma Sources for Atomic-emission Spectrometry''Affinity Chromatography''Determination of Heavy Metals'Society for Analytical ChemistryObituariesNew British StandardsPublications ReceivedConferences and MeetingsCourseAnalytical Division DiarySilver MedalVolume 16 No 6 Pages 175-196 June 197PADSDZ 16(6) 175-196(1979)I SSN 0306-1 396PROCEEDINGSJune 1979OF THEANALYTICAL DIVISION OF THE CHEMICAL SOCIETYOfficers of the Analytical Divisionof The Chemical SocietyPresidentR. BelcherHon. SecretaryP. G .W. CobbHon. Treasurer Hon. Assistant SecretariesJ. K. Foreman D. I. Coomber, O.B.E.; D. C. M. Squirrel1Secretary Hon. Publicity and Public Relations Officer Editor, ProceedingsDr. A. Townshend, Department of Chemistry,University of Birmingham, Birmingham, 61 5 2TTMiss P. E. Hutchinson P. C. WestonProceedings is published by The Chemical Society.Editorial: The Director of Publications, The Chemical Society, Burlington House, London, W1 V OBN.Telephone 01 -734 9864. Telex 268001.Subscriptions (non-members): The Chemical Society, Distribution Centre, Blackhorse Road,Letchworth, Herts., SG6 1 HN.Non-members can only be supplied with Proceedings as part of a combined subscription with The Anslystand Analytical Abstracts.@ The Chemical Society 1979THE CHEMICAL SOCIETYA Conference onINORGANIC AND ORGANIC POLLUTANTS IN THETROPOSPHERE AND NATURAL WATERSSeptember 26-28 1979The Queen's University of BelfastThis Conference is being organised at the request of the lnterdivision Committee,the Microchemical Methods Group and the Electroanalytical Group. The PlenaryLecturers will be Professor K. H. Becker, Dr. W. S. Clough, Professor R. B. Woodand Dr. A. M. Ure.Registration fees are: delegates f 10; students f 2. Delegates will be accommo-dated in halls of residence in South Belfast.For further details and application forms contact Dr. J. F. Gibson, The ChemicalSociety, Burlington House, Piccadilly, London, W1 V OBN.In addition there will be 18 other lectures

ISSN:0306-1396    

DOI:10.1039/AD97916FX020

出版商:RSC    

年代:1979

数据来源: RSC

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June, 1979 ANALYTICAL DIVISION DIARY 195Analytical Division Diary, continuedJuly , continuedTuesday, loth, 9 a.m.-“Ion-exchange and Ion-pair Chromato-Alternate Sessions on :“Practical Column Packing,” by Mary T.Gilbert and A. F. Fell.“Equipment-Columns, Connectors, Injec-tors,” by Professor J. €3. Knox and A.Pryde.“Practical Applications,” developed anddemonstrated by the manufacturers.“Applications of HPLC in Biological andPharmaceutical Analysis,” by A. F. Fell.Wednesday, llth, 9 a.m.-“Principles of Column Testing,” by ProfessorAlternate Sessions on :graphy,” by Professor J. H. Knox.J. H. Knox.“Practical Column Testing,” by ProfessorJ. H. Knox and A. Pryde.“Method Selection and Equipment-Pumps, Detectors and GradientSystems,” by Mary T.Gilbert and A. F.Fell.“Practical Applications, ” developed anddemonstrated by the manufacturers.Problem Session-where participants will beable to put questions to a panel of experts.Department of Chemistry, The University,West Mains Road, Edinburgh.Thursday and Friday, 12th and 13th:EdinburghScottish Region, in association with the Uni-versity of Edinburgh Chemistry Depart-ment and the Wolfson Liquid Chromato-graphy Unit : Advanced Seminar Course onHigh-performance Liquid Chromatography.Thursday, 12th, 11 a.m.-“Method Development and Optimisation inHPLC,” by Professor J. H. Knox.“HPLC in Biochemical Analysis,” by R. A.Hartwick.Seminar Discussion Sessions : participants willdivide into groups for discussion of methodselection and optimisation ; current develop-ments in LC techniques and equipment;preparatory-scale HPLC.Friday, 13th, 9 am.-“Environment Analysis by HPLC,” by A.Pryde.Seminar Discussion Sessions : participants willdivide into specific interest groups to dis-cuss problems and applications in traceanalysis ; biological and clinical analysis ;pharmaceutical analysis ; design of LCfacilities in industry.Department of Chemistry, The University,West Mains Road, EdinburghJUNEWednesday, 20th, 2 p.m.: LondonExtraordinary General Meeting of the AnaIy-Royal Institute of Chemistry, 30 Russelltical Division.Square, London, W.C. 1.Wednesday, 20th, 6 p.m.: LondonSouth East RBgion.“Present and Future Role of Public Analy-Linnean Society, Burlington House, Picca-sts,” by A.J. Harrison.dilly, London, W. 1.JULYSunday to Friday, 1st to 6th: CambridgeXXI Colloquium Spectroscopicurn Inter-nationale and 8th International Conferenceon Atomic Spectroscopy, organised by theAssociation of British Spectroscopists withthe support of the Royal Society, IUPAC,the Atomic Spectroscopy Group of theAnalytical Division of the Chemical Societyand the Institute of Physics.The University, Cambridge. (For moredetails see this issue, p. 193.)Wednesday and Thursday, 4th and 5th:EdinburghAnalytical Divison on “Research andDevelopment Topics in Analytical Chem-istry. ’’Wednesday, 4th, 12 noon-“The Determination of Atmospheric Con-stituents (SO,, NO,, etc.) Using Piezo-electric Crystal Sensing Devices,” by S.Cooke and T.S. West.“Pollution Studies in the Clyde Sea Area,” byJane Smith-Briggs.“Concentration Procedures for Trace MetalAnalysis by Spark-source Mass-spectro-metry,” by Karen H. Murphy and A. M.Ure.“New Methods of Sampling Liquid Steel,” byJ. McCaig, A. Cummingham, J. Lindsay,J. M. Ottaway and J. Little.“Determination of Antimony and other Ele-ments in Steel by Atomic-absorptionSpectrophotometry with the Introductionof Solid Samples into an Induction Furn-ace,’, by A. M. Aziz-Alrahman and J. B.Headridge.“Some Applications of Inductively-coupledPlasma Emission Spectrometry t o theAnalytical Division DiaryPrinted by Heffers Printers Ltd Cambridge EnglandDetermination of Toxic Trace Elements,’,by D.L. Millard, R. D. Snook and G. F.Kirkbright.“The Application of Differential Spectrophoto-metry to the Determination of FluorideUsing AFBS,” by C. Jordan.“Degradation Studies of CephalosporinsUsing Differential-pulse Polarography, ” byN. M. Fayad and A. G. Fogg.“Multi-element Analysis by Solvent Extrac-tion and HPLC of Metal-chelate Com-plexes,” by E. B. Edward-Inatimi andJ. A. W. Dalziel.“Some New Analytical Methods Based onChemiluminescence,” by J. L. Burguera.Thursday, 5th, 9.15 a.m.-“The Analysis of Theophylline by PMLC,” byPamela Naish.“Ion-exchange of Sodium Dodecylsulphateand Related Materials,” by G. J. Moody,J. 0. Rutherford, J. D. R. Thomas andB. J . Birch.“A Polymeric-membrane Calcium-selectiveElectrode with Covalently Bound Ion-exchange Sites,” by A.T. Ellis, G. C.Corfield and L. Ebdon.“Acoustic Emission-the Language ofFracture, ” by T. Lilley.“The Luminescence Analysis of 6-Mercapto-purine and Related Compounds,” by A. I.Al-Mosawi, J. N. Miller and J. W. Bridges.“Analysis and Uses of Occluded Species inZeolites,” by A. Araya and A. Dyer.“The Nuclear Microprobe Determination ofTritium Distributions in Metals,” by P. J.Mitchell and J. W. McMillan.“Applications of Derivative UltravioletSpectroscopy in Pharmaceutical Analysis, ’by A. F . Fell and G. Smith.Heriot-Watt University, Riccarton Campus,Edinburgh.Monday to Wednesday, 9th to 11th:EdinburghScottish Region, in association with the Uni-versity of Edinburgh Chemistry Depart-ment and the Wolfson Liquid Chromato-graphy Unit : Introductory Course onHigh-performance Liquid Chromatography.Monday, 9th’ 2 9.m.-Introduction by Professor C. Kemball.Opening Remarks by Professor J. H. Knox.“Basic Theory for HPLC,” by P. A. Bristow.“Equipment for HPLC,” by A. Pryde.“Normal and Reversed Phase HPLC,” byMary T. Gilbert.[continued inside back cove

ISSN:0306-1396    

DOI:10.1039/AD97916BX022

出版商:RSC    

年代:1979

数据来源: RSC

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Vol. 16 No. 6 June 1979 of the Ana I yt ica I Division of the Chemical Society Robert Martin Caven, 1870-1934 Few chemists today are familiar with the name of Robert Martin Caven, apart from sexa- genarians and septuagenarians reared on his book on Qualitative Analysis. Yet he qualifies for a place in a gallery of British analytical chemists, for he occupied the first Chair con- nected with Analytical Chemistry ever to be created in the UK.* Caven was born a t Southampton in 1870.He attended Wyggeston Grammar School, Leicester, and then worked for 4 years with a wholesale chemist. He began his under- graduate studies at University College, Notting- ham, and graduated as a BSc (London, External) in 1892. Having served for 3 years as assistant to Dr. Alfred Hill, the Birmingham City Analyst, he was appointed as Assistant Lecturer a t his old college under Professor Frank Clowes.He rose to Senior Lecturer, but left Nottingham in 19 18 to become Principal of Darlington Tech- nical College. The duties, which were mainly administrative, did not appeal to Caven, and when he was offered the Chair of Inorganic and Analytical Chemistry a t the Glasgow Royal Technical College, he accepted with alacrity.He occupied this Chair until 1934, when he died suddenly and unexpectedly. He wrote on religion (his father was a Baptist Minister), popular science, chemical education and the history of science. He took part in the activities of local sections of the Institute of Chemistry and the Society of Chemical Industry. It is said that he was an out- standing public speaker and lecturer and this must have played a major part in his success as a teacher.Caven contributed much more to inorganic than analytical chemistry and as it is the latter aspect that concerns us no further reference will be made to his considerable work in the field of inorganic chemistry. The chief contribution to analytical chemistry made by Caven was his book on qualitative analysis.It was as good a book as existed a t that timc, but it contained the long-standing errors I have referred to many times elsewhere. Curiously enough, it contained no physico- chemical theory. It was later supplanted by a Caven had wide-ranging interests. more extensive book, which therefore succeeded in multiplying the errors. All things con- sidered, Caven’s was probably the best general book on qualitative analysis ever produced in the United Kingdom, until small-scale methods were adopted.His book on quantitative analysis was far less popular and, as far as I can discover, was used only locally. Caven’s analytical contributions to the scientific literature were meagre ; they included work such as the determination of oxygen in water, the use of asbestos fibre for the filtration of precipitated cuprous oxide, the qualitative * Professor D.Thorburn Burns (Plenary Lecture, Euroanalysis 111, Dublin, 1978) regards James Emerson Reynolds as being the first Professor of Analytical Chemistry in these islands. As far as the bare title is concerned, this is correct, but i t does not fit the 20th century definition, which can only be applied when the person concerned occupies a Chair at a University.Reynolds was employed by the Royal Dublin Society in 1867 and received the title of Professor of Analytical Chemistry in 1871, presumably from the Society. In 1875, he was appointed to the Chair of Chemistry a t Trinity College; a Chair of Analytical Chemistry did not exist.175 Hence, Caven must be considered the first.176 ELECTROANALYSIS IN INDUSTRY Proc. Analyt. Div. Chem. SOC. separation of arsenic, antimony and tin, and modifications to the basic acetate separation. His examination of selective oxidising agents in the qualitative and quantitative analysis of mixed halides ( J . SOC. Chem. Ind., 1909, 28, 505) was perhaps his most extensive study, but it mainly consisted of comparing reagents proposed in earlier investigations.Although useful, none of his analytical work was original and it was far less profound than his inorganic contributions. His last contribution to quanti- tative analysis was made a decade before he was appointed to the Chair. Most of his published work was read a t regional meetings of the Society of Chemical Industry.They met in towns such as Burton, Derby and Nottingham. Presumably at that time (1895 onwards) train services were satis- factory, for it was the only means of transport. The name of the Chairman was always provided and the discussion was always reported in full. Caven’s contributions have left no mark on analytical chemistry and were never mentioned in contemporary text-books.Likewise, during the heady years of the 192Os, when oxine, dithizone, redox indicators, the sodium reagents, new titrants and the polarograph were dis- covered, and microanalysis and spot-tests came to the fore, Caven contributed nothing to this golden age of analytical chemistry. It was left to Mitchell and Ward to record these developments in their book “Modern Methods in Quantitative Chemical Analysis” ( 1932).It has to be admitted that Caven did very little to advance analytical chemistry, which explains why his name is missing from its literature. The reason is not hard to find. He was put in the position of having to serve two entirely different masters and the one could not be served faithfully without detriment to the other-in this instance analytical chemistry.Even in those days the subjects were already too far apart to be combined. Yet even today I have had to argue against such a combination. Caven did well in the circumstances to contri- bute as much as he did, but it fell short of what might have been expected from a department partly devoted to analytical chemistry. Against this must be set his place as a first-class teacher (alas, how ephemeral is such a reputation), as an inorganic chemist, and above all, his reputation as a person.Caven appears to have been a man of outstanding sincerity and honesty and it is evident from the records that his untimely end brought great grief to his colleagues. Some other questions remain to be answered. It was to be expected that the Royal Technical College would create a Chair connected with Analytical Chemistry.The College (now the University of Strathclyde) was the successor of the Andersonian University, which had pro- duced great names such as Ure, Penny and Dittmar. What impelled its Council to create this position? More important, why was the Chair discontinued when its “. . . highly esteemed and distinguished Professor . . .” passed away? Our ancient and venerable branch of chemistry had to wait twenty-two years before a similar Chair was created and then it was elsewhere. Only those with access to the records can answer these questions. My thanks are due to Dr. J. M. Ottaway, Dr. A. Townshend and Dr. W. I. Stephen for their help in providing information. R. BELCHER

ISSN:0306-1396    

DOI:10.1039/AD9791600175

出版商:RSC    

年代:1979

数据来源: RSC

摘要:

176 ELECTROANALYSIS IN INDUSTRY Proc. Analyt. Div. Chem. SOC. Electroanalysis in Industry The following is a summary of one of the papers presented at a Meeting of the Electroanalytical Group held on June 14th, 1978, at Kodak Limited, Harrow, Middlesex. Applications of Polarography and Ion-selective Electrodes in the Photographic Industry E. C. WeIler Kodak Limited, Headstone Drive, Harrow, Middlesex Polarographic analysis and ion-selective electrode potentiometry are both valuable tools for quality control, process control and problem solving in the photographic industry.Ion-selective Electrodes bromide, chloride, iodide, sulphide and ammonia electrodes. A wide variety of ion-selective electrodes are employed. These electrodes include pH, The most widely used is the pHJune, 19 79 ELECTROANALYSIS I N INDUSTRY 177 electrode, which is employed in the control of emulsion making, processing solution control, analysis of effluent, etc.While the use of pH electrodes in the production of photographic emulsion presents several problems, e.g., gelatin - glass membrane interactions, the selection of pH electrodes for use in processing solutions is of great importance.Control of pH in processing solutions is required to 60.03 pH unit at pH values up to 12 in the presence of more than 1 M amounts of sodium ions. As all pH electrodes show some alkaline error, care in the selection of appropriate electrodes under our conditions has proved vital. Having selected suitable types, regular monitoring has been carried out to ensure the continuity of good electrodes.Very few types of electrodes passed our tests and even subsequent tests of selected types revealed many unsuitable electrodes. During the manufacture of photographic emulsions, halide and silver levels are monitored with silver halide electrodes. These are generally metal-coated electrodes but could be silver halide membrane electrodes. The latter are not generally applied, mainly on cost grounds, offering no significant advantages over the former kind of electrodes.Indeed, in gelatin samples, the response times of membrane electrodes appear to be longer than the metal-coated electrodes. Silver sulphide electrodes are used as end-point detectors in the potentiometric titration of silver in emulsions and coated products.Once again, electrodes of the second kind are generally employed. Areas where membrane halide-selective electrodes have been employed very successfully are the determination of chloride in plating solutions and iodide in developers. Chloride in Plating Baths One of the processes carried out during camera production is copper plating in an acid bath. The level of chloride in the bath is important and this is one of the species suitable for deter- mination by ion-selective electrodes in plating baths.l The response of the chloride ion- selective electrode is linear down to 1 p.p.m.in typical plating solutions. In order to over- come ionic strength fluctuations, and for speed, a known-addition technique (single addition) was employed. Good correlation was obtained for plating solutions between the existing on- line control method, turbidimetry and the electrode technique.Iodide in Developers The determination of iodide in developers is often required for formula analysis but the titrimetric methods used previously have either been time consuming or have produced variable results. Ion-selective electrodes offer an attractive approach to iodide analysis, particularly in the presence of large amounts of other halides.Bromide is present typically at between 100 and 500 times the iodide concentration. However, the experimentally deter- mined selectivity coefficient is small for bromide (2 x and the iodide electrode can there- fore measure low levels of iodide in solutions containing bromide at the level normally found in developers.Unfortunately, solid-state halide membrane electrodes cannot be used in strongly reducing media such as photographic developers. Under acidic conditions, however, the iodide electrode has been employed successfully in the known-addition mode. Ammonia Probe An ion-selective electrode that has shown itself to be very useful is the ammonia gas sensing probe.Two applications of this electrode include the determination of ammonia in developers and in gelatin. Colour prints produced by a two-bath process, developer and bleach-fix, can be stained if the photofinisher laboratory allows contamination of the developer by bleach-fix. The magnitude of the effect depends on the level of contamination, and analysis of the developer to determine free ammonia is used as an indication of such contamination.Before the ammonia probe became available, this analysis had been performed by microdiffusion using Conway cells. This last method was time consuming and required a good degree of skill. The application of the ammonia probe saves time and it is easier to use than the microdiffusion technique. One of the common constituents of colour developers is hydroxylamine sulphate, which also causes a response from the probe.Indeed, a linear calibration is obtained for hydroxylamine, which would cause interference with the probe in this application. Elimination of this inter- ference can be accomplished by utilising the reaction of ketones with hydroxylamine to form1’78 ELECTROANALYSIS IN INDUSTRY Proc.AnaZyt. Div. Chem. SOC. oxiines, which do not cause a response from the probe. Linearity of the probe response in the presence of acetone and above pH 13 continues to below 1 p.p.m. (Fig. 1). Once again, the known-addition technique is used for routine analysis, so that errors caused by potential drifts and high ionic concentration effects on the partial pressure of ammonia in solution are avoided.A good correlation was obtained between the electrode and microdiffusion methods for samples of contaminated developers. Clearly, if one is concerned about the level of ammonia in the developing solutions, the amount of ammonia in the photographic paper raw materials, for example gelatin, is also important. The same technique as was described above is employed, except that no acetone is added when determinining the ammonia level in gelatin.Polarograp hy Polarography is finding more and more applications in several areas of the photographic industry. A few examples are described. H ydroxylamine The effect of hydroxylamine on the ammonia probe has already been described. the probe could be used to determine hydroxylamine, the response is very sluggish.probe requires a long wash cycle between measurements. conveniently by differential-pulse polarography. p.p.m. have been obtained. Although Also, the Hydroxylamine can be determined Linear calibrations down to at least 20 Thiosulpbate Possible contamination of the developing tanks at photofinishers is a common analytical problem. The possible ammonia contamination has already been discussed and a related request is the analysis of developers suspected of thiosulphate contamination. This requires an analysis to determine parts per million levels of thiosulphate in the presence of a large excess of sulphite and developing agents. Pulse polarography has enabled this determination to be carried out simply and rapidly (Fig.2). 100 10 < 2 91 - Z Y 0.1 0 Fig.1. Effect of acetone on the potentio- metric response of the ammonia probe in solutioris containing hydroxylamine. A, Ammonia plus a 3.5 nl-l solution of hvdrox- I I I 0 -0.2 -0.4 Voltage ylamine srhphate plGs acetone; B, ammonia plus a 3.5 g 1-1 solution of hydroxylamine sulphate. amounts of sulphite. Fig. 2. Differential-pulse polarogram of sodium thiosulphate in the presence of large Metals The polarograph is used for the determination of extremely low levels of metaIs (less than M) when other techniques are inappropriate.Jun.e, 1979 PLASMA SOURCES FOR ATOMIC-EMISSION SPECTROMETRY 179 Conclusion This paper has illustrated some of the applications of ion-selective electrodes and polaro- Both techniques are actively expanding in this area of graphy in the photographic field. industry. Reference 1. Frant, M. S., Plating, 1971, 686.

ISSN:0306-1396    

DOI:10.1039/AD9791600176

出版商:RSC    

年代:1979

数据来源: RSC

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Jun.e, 1979 PLASMA SOURCES FOR ATOMIC-EMISSION SPECTROMETRY 179 Plasma Sources for Atomic-emission Spectrometry The following is a summary of the paper presented at a Meeting of the Scottish Region held on September 14th, 1978, at the University of Strathclyde, Glasgow. Assessment of High-frequency Induced Plasma for Atomic-emission Spectrometry L. de Galan Laboratoyium voor A nalytische Scheikunde, Technische Hogeschool Delft, Jaffalaan 9, Delft, The Netherlands For the purpose of this paper, a plasma is defined as a hot, radiating gaseous mixture of neutral particles (atoms, molecules) and electrically charged particles (electrons, ions), the presence of the latter being an essential requirement for sustaining its properties.According to this definition, flames and laser beams are not plasmas, although for analytical purposes their properties are comparable to those of d.c.arcs, a.c. sparks, hollow cathodes and other electrical discharges, which are plasmas in the above sense. Recently, two novel types of plasma have gained analytical interest : the inductively coupled radiofrequency plasma (ICP) and the microwave-induced plasma (MIP).Both are generated by the transfer of energy from high-frequency electromagnetic waves to electrons, which in turn impart the acquired energy to the heavier particles (atoms, ions, molecules) in the plasma. In this paper we shall examine the physical basis and instrumentation of these plasmas and assess their potential for atomic-spectrometric analysis. Physical Basis For example, it is of analytical interest to note that the two plasmas under consideration are electrodeless discharges and thus not hampered by the properties and purity of electrodes as are arcs and sparks.However, a more fundamental distinction is based on the plasma temperature. This parameter appears in the four basic physical processes that occur inside a plasma. 1. Maxwell’s mean velocity (v) of the particles of a species: &mv2 w KTkin, where Tkin is the kinetic temperature ; specifically, Te1 is the kinetic temperature of the electrons.2. Saha’s equilibrium between ions and atoms of an element : ni/na w exp(-Ei/kTi), where Ei and Ti are the ionisation energy and temperature, respectively. 3. A similar expression for the equilibrium between atoms and molecules of an element: rYt.a/nM., m exp(-Ed/kTd), where E d and T d are the dissociation energy and temperature, respectively.4. Boltzmann’s distribution of particles over various energy levels above the ground state: n*/no m exp(-Eex,/kTexc), where Eexc and Text are the excitation energy and tempera- ture, respectively. Now, according to Einstein’s radiation law, the detected emission intensity of a particular spectral line is directly proportional to the density of excited particles, n*.Apparently, this quantity is a complicated function of particle constants (Ei, E d , Eexc) and plasma parameters (Ti, T d , Text). In addition, the volatilisation of condensed sample particles inside the plasma is controlled by the kinetic temperature of the heavier species.Plasmas can be mutually distinguished by various means.180 PLASMA SOURCES FOR ATOMIC-EMISSION SPECTROMETRY PrOC. Analyt. D+d. Chew. SOC. On this basis, plasmas can be distinguished in two categories. Firstly, we have plasmas in thermal equilibrium, where all of the above temperatures are equal. Such plasmas generally require a substantial amount of electrical power (>1 kW).Examples are the flame (not a plasma, temperature T = 2 500 K), the d.c. arc (T = 5 500 K) and (approximately) the ICP (T = 5 000 K). The higher the temperature of such plasmas, the more rapidly an introduced sample is volatilised and dissociated and the higher is its atomic or ionic emission intensity. This explains the advantage of high-temperature sources (arcs, ICP) over low-temperature flames for atomic-emission spectrometry.However, except for a spark (T = 20 000 K), plasmas in thermal equilibrium are unable to excite radiation from non-metallic elements, such as halogens, and permanent gases. Excitation of radiation from these elements is possible with a second category of plasmas: those which are not in thermal equilibrium, because the various temperatures have different values.In general, we find that Te1> T i o n >Text > T d 3 Tkin. Examples of this type of plasma are the hollow cathode (hence the appearance of filler gas lines in the spectra of hollow-cathode lamps used for at omic-absorption spectrometry) and the RIIIP. Such plasmas require much less electrical power ((100 W), but their low kinetic temperature (Tkin = 700 K) makes it very difficult to volatilise liquid (dis- solved) samples.On the other hand, the extremely high electronic temperature (Te1 >50 000 K) stimulates the population of very high energy levels such as are found in atoms and ions of non-metals (Eexc >10 eV). Instrumentation for and Evaluation of the MIPl The microwave-induced plasma is generated in a gentle flow of noble gas (10-100 ml min-l) flowing through a narrow quartz capillary ( i d 2 mm) enclosed by a microwave cavity.The cavity is connected to a generator that produces electromagnetic radiation (2 450 MHz, 50-100 W) inside the cavity. Without a sample, the plasma region of length about 1 cm emits only the spectrum of the carrier gas (argon or helium), which contains relatively few lines.This allows the use of low-dispersion optics, so that the M I P is essentially a low-cost plasma (say L5 000 for single-channel observation). The plasma is stable for several hours and uses little gas. Although conventional nebulisation of solutions has been reported for the MIP in argon, this is only moderately successful for metal analysis,2 where competitive methods are much more powerful.” The more important potential for the determination of non-metals is possible with a helium plasma, but this requires a preliminary volatilisation of the sample before it is introduced in gaseous form into the MIP. For this reason, the MTP has been predominantly advocated as an element-selective detector for gas chromatography, where it allows selective detection of hydrogen, carbon, oxygen, nitrogen, phosphorus, sulphur, chlorine, bromine and iodine.4 However, its unique properties merit closer attention for the determination of non-metals in other types of samples than can be handled by a gas chromatograph.The main problem is the introduction of a sample. Instrumentation for the ICP5 The ICP torch consists of three concentric quartz tubes sticking through a copper induction coil (id.2 cm) connected to an RF generator operating, with few exceptions, at 27.2 MHz. In the most popular version argon is flowing between the two outer quartz tubes at a rate between 10 and 20 1 min-l. At the expense of higher power (7-15 kW), argon can be replaced with nitrogen. Generators also differ in another aspect.Most operate at a crystal-controlled fixed frequency and require electrical tuning facilities for an efficient transfer of the power to the plasma. Other generators realise this tuning by allowing the radiofrequency to vary slightly around its nominal value. At present there is no clear preference for either type. In either instance argon (I 1 min-l) is used to transport a nebulised sample solution through the central quartz tube.Owing to the Iow argon flow-rate, sample introduction is still problem- atic: pneumatic nebulisers6 require extremely small spacings and thus tend to clog easily; ultrasonic nebulisers’ have often been advocated without gaining widespread acceptance. Preliminary volatilisation of solid samples (by spark sputtering techniques) or liquid samples * The aIternative capacitively coupled microwave plasma (CMP) uses more energy (700 W) and will not be discussed here.3 This permits operation a t moderate power (1-2 kW).June, 19 79 PLASMA SOURCES FOR ATOMIC-EMISSION SPECTROMETRY 181 (by filament evaporation) has also been reported.Of the alternatives, the pneumatic nebul- iser is still the most versatile and reliable device.A nebuliser for highly viscous solutions has been In view of its temperature (9 000 K in the coil region, 5 000 K at 15 mm above the coil), the ICP is capable of exciting atomic and ionic spectral lines of all metals. Samples that contain significant amounts of transition elements (iron, titanium, vanadium, tungsten) emit extremely rich spectra that require high-resolution optics to reduce line overlap.Together with the high-power generator this makes the ICP an expensive type of plasma (E30 000 for single-channel observation). The inherent capability of emission spectrometry for multi- element analysis has induced many manufacturers to equip their ICPs with polychromal ors with automatic read-out facilities for 10-30 spectral positions.This increases the iniiial investment even further. Analytical Potential of the ICP Undoubtedly, the inductively coupled plasma is rapidly gaining acceptance as a versatile This is also This interest stems For about 40 elements the detection limits are below 10 pg 1-1 (for ten, below 0.1 pg 1-l), whereas the calibration graphs are linear over 4 to 5 orders of magnitude. After careful optimisation the ICP appears to be free from both chemical interferences (problematic in flames) and ionisation interference (annoying in d.c.plasmas).ll Examples from the literature show that it is sufficient to match samples and references for solvent properties12 and a major component, if present in large excess (iron for steel analysis13). If we accept a precision of about 1%, then a single determination need not take longer than 20 s.With multi-channel observation facilities this allows a high sample load. 4. Uniform conditions. Although it is true that three basic parameters (power, gas flow, observation height) may be optimised for each individual element, the loss in sensitivity arising from the use of standard conditions is not more than a factor of t ~ 0 .l ~ These properties make the ICP extremely suitable for simultaneous trace-element detennin- Provided that the However, the prospccts Improved stability and capability of solution nebulisers and direct introduction of solid samples are desirable. The high power requirements (to 20 kW from the mains) and the argon consumption (10-20 1 min-l) make the ICP less attractive than competitive plasmas.Even with good optics, line overlap remains a problem and samples that emit complex spectra 'frequently require the use of less than optimal spectral 1ines.lg Present intensity tables developed for electrical discharges are not always reliable for the ICP. Background correction also offers some problems, especially in polychromator instrumenk20 multi-element method for the determination of metals in dissolved samples.evidenced by the growing number of commercially available instruments. from four favourable properties of the ICP. 1. Detection power.1° 2. Low interference levels. 3. Analysis speed. ations in a variety of samples, q., alloys,15 soil,16 plants1' and water.ls sample load is high, the initial investment need not form an obstacle.for the ICP will become even better if three remaining problems can be overcome. 1. Sample introduction. 2. Running costs. 3. Line selection. This factor may seriously detract from the detection limits. Conclusion The two high-frequency plasmas discussed in this paper differ in physical properties, in instrumental development and in analytical capabilities.The M I P offers unique possibilities for the spectroscopic determination of non-metals, but awaits further development. The ICP has successfully overcome its teething problems and may become the method of choice for the determination of metals in solution. It is not as sensitive as electrothermal atoniic-absorp- tion spectrometry, but superior in many respects to d.c. plasma emission and flame atomic- absorption spectrometry. The ultimate decision depends not only on further improvement in ICP instrumentation, but also on the development of these competitive methods of atomic- spectrometric analysis.182 1.2. 3. 4. 5 . 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. AFFINITY CHROMATOGRAPHY References Proc. Analyt. Div. Chem. SOC. Greenfield, S., McGeachin, H.McD., and Smith, P. B., Talanta, 1975, 22, 1; 1975, 22, 553; 1976 23, 1. Reenakker, C. I. M., Bosma, B., and Boumans, P. W. J. M., Spectrochim. Acta, 1978, 33B, 373. Govindaraju, K., Mevelle, G., and Chouard, C., Analvt. Chem., 1976, 48, 1325. van Dalen, J. P. J., de Lezenne-Coulander, P. A., and de Galan, L., Analytica Chim. Acta, 1977, 94, 1. Barnes, R. M., Crit.Rev. Analyt. Chem., 1978, 7, 203. Kniselev, R. N., hmenson, H., Butler, L. C., and Fassel, V. A., Appl. Spectrosc., 1974, 28, 285. Olson, K. W., Haas, W. J., and Vassel, V. A., Analvt. Chem., 1977, 49, 632. Suddendorf, R. F., and Boyer, I<. W., Analyt. Chem., 1978, 50, 1769. Walcott, J . W., and Butler-Sobel, C., A p p l . Specfrosc., 1978, 32, 591. Boumans, P. W. J . M., Bastings, I>. C . , de Boer, F. J., and van Kollcnburg, L. W. J., Z. Analyt. Chenz., J-arson, G. F., and Fassel, V. A., Analyt. Chcvn , 1975, 47, 238; 1976, 48, 1161. Grecnfield, S., McGeachin, H. McD., and Smith, P. R., Analvtica Chim. Acta, 1976, 84, 67. Ohls, K., Koch, K. H., and Rote, H., 2. Analvt. Chem., 1977, 284, 177. Boumans, P. W. J . M., and de Boer, I?. J., Spectrochinz. Acta, 1975, 30B. 309. Butler, C. C., Kniseley, R. N., and Fassel, V. A,, Analvt. Chem., 1975, 47, 825. Scott, R. H., and Kokot, M. L., Analytica Chivn. Acta, 1975, 75, 257. Dahlquist, R. L., and Knoll, J. U7., AppZ. Spectrosc., 1978, 32, 1. Wince, K. K., Fassel, V. A., Kniseley, R. N., Dekalh, E., and Haas, W. J . Spectvochim. Acta, 1977, Abdallah, M. H., Mermet, J. M., and Trassy, C., Analytica Chim. Acta, 1976, 87, 329. l>arson, G. F., Fassel, V. A, Winge, R. K., and Kniseley, R. N., A+$. Spectrosc., 1976, 30, 384. 1978, 291, 10. 33B. 327.

ISSN:0306-1396    

DOI:10.1039/AD9791600179

出版商:RSC    

年代:1979

数据来源: RSC

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182 AFFINITY CHROMATOGRAPHY Proc. Analyt. Div. Chem. SOC. Affinity Chromatography The following is a summary of one of the poster presentations given at a Meeting of the Analytical Division held on February 7th, 1979, at the Scientific Societies Lecture Theatre, London. Affinity Chromatography: Separation of Alkaline Phosphatase and of Acetylcholinesterase P. J. Butterworth and D. T. Plummer Defiartrrzent of Biochemistry, Chelsea College, University of L o d o n , London, S W3 GLX At its inception, affinity chromatography was regarded as a technique in which biospecific interactions between a protein and a ligand attached to an inert support could lead to specific selection of a particular protein component from a mixture, and so bring about an impressive degree of purification in a single step.The specificity of the protein - ligand interaction does mean, however, that the use of a particular chromatographic medium is limited to one protein. Separation of a different class of protein or enzyme requires a chromatographic medium carry- ing a different ligand that can interact suitably with the new enzyme. The problem of the limited flexibility of the system can be overcome by using a ligand that has some affinity for several proteins so that the same medium can be used in the purification of any protein that forms a reasonably stable complex with the ligand.We report the use of a general ligand of this type for the separation of pig kidney alkaline phosphatase, and in addition we describe a specific system for the isolation of acetylcholinesterase. Affi-Gel Blue (Bio-Rad Laboratories Ltd.) consists of the dye Cibacron Blue coupled to cross-linked agarose beads.The dye binds to nucleotide-requiring enzymes with high affinity in an interaction which has been said to mimic an enzyme - nucleotide interacti0n.l Thus, Cibacron Blue is being used as a general affinity ligand for dehydrogenases, kinases, etc.Surprisingly, pig kidney alkaline phosphatase is markedly inhibited competitively by Cibacron Blue (Ki = 50 p ~ ) . ~ It is probable that the dye binds to a hydrophobic region adjoining the active site and the sulphonate residues on the dye penetrate the active site and bind in a manner analogous to that of a phosphate substrate. We investigated, therefore, whether the dye could serve as an affinity ligand for alkaline phosphatase.A 5-ml portion of pig kidney alkaline phosphatase (approximately 10% pure) in 50 mM Tris buffer, pH 7.6, was loaded on to a column (20 x 1.5 cm) of Affi-Gel Blue equilibrated with theJune, 1979 DETERMINATION OF HEAVY METALS 183 same buffer. Approximately 60 ml of buffer were run through the column to displace any unbound protein and then the alkaline phosphatase was eluted, either by application of 0.1 M sodium chloride in the Tris buffer or by changing the pH of the buffer to 9.0.Whichever method was used the enzyme was recovered with almost lOOyo yield as two peaks, a minor one representing about 14% of the enzyme and eluting first, followed by the major peak containing the remainder.The heterogeneity is possibly related to differences in the amount of sialic acid attached to the enzyme molecules, a cause of most of the electrophoretic and chromatographic heterogeneity of kidney alkaline phosphatase. The affinity gel appears to be a useful addition to existing methods of purifying alkaline phosphat ases. The more classical approach3 used in separations by affinity chromatography is seen in the next example, in which a ligand specific for acetylcholinesterase is used partially to purify this enzyme from pig brain.The affinity material was 1 -methyl-9- (Nk-aminocapro yl) -p-amino- propylaminoacridinium bromide coupled to Sepharose 4B.* Acetylcholinesterase from pig cerebral cortex was solubilised with 0.1 yo Triton X-100, then run through the affinity column (bed volume 12 ml) at about 30 ml h-l.The column was washed with 30 mM sodium phosphate solution (pH 7) until no more protein could be detected and the acetylcholinesterase eluted with buffered 10 mM decamethonium bromide, a potent inhibitor of ac2tylcholinesterase. The enzyme was then assayed after dialysis to remove the eluting inhibitor. The results obtained in a typical experiment are shown in Table I.Triton X-100 (0.1 yo m/V) was present in all solutions. TABLE I PURIFICATION OF ACETYLCHOLINESTERASE FROM PIG CEREBRAL CORTEX Enzyme activity/ Specific activity/ Dcgrce of Protein/mg pmol min-1 pmol min-l mg-1 Yield, yo purification Total applied 709 115 0.162 100 X l Recovered in peak 0.35 51.7 148 45 x 910 Further purification was achieved if the eluted peak of enzyme activity was re-run on the column. The specific activity was at least doubled and the problem then became how to measure the protein content, which was extremely low.Enzymes can thus be purified by selecting a highly specific ligand, as with acetylcholinester- ase, or a more general ligand that binds groups of proteins, as illustrated by alkaline phosphat- ase. In both instances a high degree of purification can be obtained in one simple step using only small amounts of affinity material. References 1. 2. 3. 4. Thompson, S. T., Cass, K. H., and Stellwagen, E., Proc. Natn. -4cad. Sci. U.S.A., 1975, 73, 361. Woodroofe, M. N., and Butterworth, P. J., Arch. Biochem. Biophys., in the press. Wilchek, M., and Hexter, C. S., Meth. Biochem. Analysis, 1976, 23, 347. Reavill, C. A,, and Plummer, D. T., J . Chromat., 1978, 157, 141.

ISSN:0306-1396    

DOI:10.1039/AD9791600182

出版商:RSC    

年代:1979

数据来源: RSC

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June, 1979 DETERMINATION OF HEAVY METALS 183 Deter mi nation of H eavy M eta Is The following are summaries of two of the papers presented at a Joint Meeting of the Micro- chemical Methods, Atomic Spectroscopy and Radiochemical Methods Groups held on February 8th, 1979, at the Laboratory of the Government Chemist, London. Determination of Heavy Metals: The Evolution of Spectrochemical Tech n iq u es R.N. P. Farrow and G. F. Lewis BDH Chemicals Ltd., Broome Road, Poole, Dorset Before considering the determination of heavy metals, the term should be defined. A first approach is the old separation table for the identification of inorganic mixtures, where Group184 DETERMINATION OF HEAVY METALS Proc. A9zaZyt. Div. Chew. SOC. I1 contained metals that precipitated as sulphides with hydrogen sulphide in dilute acid condi- tions.The more familiar examples were copper, bismuth, mercury(II), cadmium and the residual lead that had not separated as the chloride in Group I. Secondly, we might consider a pharmacopoeia1 definition of the term. After all, the chief reason for our analytical interest in heavy metals is that metals such as lead and mercury are poisons and it is essential that they should not be present in harmful amounts in foods and medicines.The United States Pharmacopeia describes several variations of a test for heavy metals. This test, further variations of which are described elsewhere in the literature, is an example of how we carried out colorimetric analyses in the years before absorptiometers and spectrophotometers enabled us to use narrow-waveband light and so to dispense with the inconsistencies of the human eye.It will therefore serve well as the first example in following the historical development. The basic principle was as follows: we prepared a test solution of the sample according to the instruction relating to the specific material, and a comparison standard with standard lead solution; we adjusted each to a pH of between 3 and 4 with dilute acetic acid or ammonia solution; we added to each a specified volume of freshly prepared hydrogen sulphide water, diluted to volume and allowed to stand for a specified time; we then viewed the colours down- wards over a white surface-the colour of the sample had to be no darker than that of the standard.There are several points to note.(i) In this method, the term heavy metaZs included all those metals which gave coloured sulphides at pH 3-4, e.g., lead, copper, mercury(II), bismuth and cadmium, but not, for example, iron, cobalt and nickel. This was sensible because the included metals were, in general, the more harmful ones. It so happens that these were also the metals which precipi- tated in Group I1 of the old qualitative inorganic analysis scheme.(ii) The method could be improved by preparing a set of standards, and placing the sample in series with them. (ii) The comparison standard was lead and so we were expressing the result as heavy metals as lead. The method had a serious defect in that the sulphide colour of the sample could be consider- ably modified by metals other than lead so that comparison with lead standards could be difficult and misleading.For all its shortcomings, this type of procedure gave and still gives a reasonably reliable indication of whether or not the total heavy metals value so defined exceeds a certain limit; further, only very simple equipment was required. The procedure could be modified to make it more specific.For example, by employing a higher pH and by adding cyanide to complex copper and cadmium, the method could be made reasonably specific for lead, with certain reservations. However, two developments made possible the determination of individual heavy metals with greatly enhanced accuracy and precision. These were firstly, the develop- ment of organic chelating reagents, and secondly, the development of absorptiometers and spect rophot omet ers.An organic chelating reagent usually possessed several characteristics. (i) It had one or more acihc hydrogen atoms which could be replaced by a metal. (ii) It had one or more unbonded electron pairs with which to co-ordinate with the metal atom. These pairs were generally provided by nitrogen or sometimes oxygen atoms.The metal atom was thus held at the centre of a compactly organised molecule. (iii) The resulting complex was stable, and if neutral could be extracted from aqueous solution into a non-polar solvent such as chloroform or carbon tetrachloride. (iv) Many organometallic complexes were coloured and gave characteristic absorption spectra, which lent themselves to measurement, either visually or instrumentally.(v) By adjusting the pH it was often possible to exploit differences in stability between organic complexes of different metals. Metals that formed complexes with large stability constants would react with the chelating reagent at lower pH values than metals forming less stable complexes, and could therefore be determined in their presence.(vi) Also by introducing other complexing agents into the system it was often possible to enhance the specific nature of the method by masking an unwanted complex. The development of instruments made possible the following advances. Firstly, the absorb- ances could be measured far more accurately and precisely than colours could be assessed and matched by the human eye.Secondly, by using light of a narrow waveband, it was possibleJztne, 1979 DETERMINATION OF HEAVY METALS 185 to measure the absorbances at wavelengths corresponding to peaks in the absorption spectrum. This enhanced the sensitivity of the method and also made possible the measurement of one coloured complex in the presence of another if the absorption peaks occurred at sufficiently different wavelengths.Calibration graphs relating absorbance to concentration could be readily constructed. One of the earliest instruments was the Spekker absorptiometer, in which the visible spectrum was covered by selection from a series of coloured filters, each one providing a wave- band of about 30 nm. This was soon followed by the early prism spectrophotometers, one of the most well known being the Beckman DU instrument.During the same period, early recording instruments permitted one quickly to produce and compare continuous absorption spectra to optimise the experimental conditions. In the early procedures lead, for example, was extracted from a weakly alkaline solution of the sample with an excess of the reagent dissolved in carbon tetrachloride.The excess of reagent was removed by shaking the organic phase with dilute ammonia. The intensity of the red colour of the lead dithizonate was compared with standards, using a visual colorimeter. Later, when spectrophotometers became available, the excess of dithizone was allowed to remain in the organic solvent, which was now generally chloroform and the absorbance of the lead complex was measured at the appropriate absorption peak.This was well separated from the major peak for the excess of dithizone. Dithizone formed metal complexes in speci- fied experimental conditions with many metals, including copper, cadmium, bismuth and mercury. Sodium diethyldithiocarb- amate was the first reagent of its type to find favour. An excess of an aqueous solution of sodium diethyldithiocarbamate was added to a slightly ammoniacal solution of the sample.The copper complex was extracted into a solvent (either carbon tetrachloride or chloroform). The absorbance measurement was carried out at 435 nm. Mercury was often determined with dithizone, with which it formed a stable complex in fairly acidic conditions, e.g., 1 M sulphuric acid.During this period much ingenuity was shown in devising reagents and experimental conditions which would give methods selective for given metals. By the time atomic-absorp- tion spectroscopy camz on the scene, a great array of such methods was available to the analyst. In fact, virtually no reagent was specific for just one metal. Through their structural characteristics, the organic chelating agents were capable of exchanging their protons and co-ordinating with more than one metal.Paradoxically, the reagents with the best sensitivity and the widest applicability, such as dithizone, gave the greatest problems. The best we could usually achieve was to arrange the conditions so that the wanted organometallic complex predomin- ated and produced an absorbance peak which was some distance away from the peaks of other absorbing species.In the early 1960s came atomic-absorption spectrometry, which completely altered the pattern of inorganic trace analysis. Commercial instruments were soon developed and atomic- absorption spectrometry caught on rapidly. There was a lack of interference between metals coupled with good sensitivities for a wide range of elements.The introduction of atomic-absorption techniques at BDH revolutionised the determination of trace-metal impurities in our chemicals. Fifteen years ago the blanket heavy metals test was still commonly applied, but today individual heavy metals are almost always determined by atomic-absorption spectrometry. Aqueous solutions of the samples are normally sprayed into the flame and a standard additions method of calibration is used.With some very high purity grades of chemicals it is necessary to use a solvent-extraction technique with ammonium tetramethylenedithiocarbamate and 4-methylpentan-2-one. This avoids problems with high background corrections and blockage of the nebuliser by concentrated sample solutions. Occasionally coprecipitation methods are used, e.g., in the determination of trace amounts of lead and bismuth in copper and its salts.The lead and bismuth are coprecipitated with calcium carbonate in the presence of an excess of ammonia. Electrothermal atomic-absorption methods are useful in situations where high sensitivity is required. We routinely screen urine samples for thallium by means of an ammonium tetramethylenedithiocarbamate - 4-methylpentan-2-one extraction followed by carbon rod atomic-absorption spectrometry.For copper, analysts preferred the dithiocarbamate methods. The problem was often which reagent and which procedure to use. This can be combined with a solvent-extraction technique.186 DETERMINATION OF HEAVY METALS Proc. Analyt. Div. Chern.SOC. Electrothermal methods also find extensive use in the determination of heavy metal pollution of the environment. Atomic-absorption spectrometry is essentially a single-element technique and attempts to use i t for multi-element determinations have had only limited success, Atomic-emission spectroscopic methods are more readily used for multi-element determinations. Emission methods have a long history ; indeed, many metals were discovered by emission spectroscopy.These methods are widely used today, particularly in the metallurgical industry. Interest in these techniques has been renewed in recent years by the introduction of new excitation sources, particularly the inductively coupled plasma (ICP). The remainder of this paper describes some of our experiences in the use of an ICP source in conjunction with a direct- reading spectrometer.We use a Radyne R50 RF unit in conjunction with a Rank Hilger El000 direct-reading spectrometer which is set up with 44 channels. The integrated intensity for each channel is printed out on a typewriter at thc end of each exposure. We also use an Optica CF4 mono- chromator which can be used for lines that are not available on the main spectrometer.We have been using this instrument routinely for about 1 year and many of our determina- tions of trace metals in acids and solvents are carried out by using this technique. We use compromise conditions to give the best sensitivity for lead, as this is a limiting factor in many instances. In particular a 10% m/V lithium nitrate matrix, which favours high line to background ratios for lead and some other atomic lines, was used.The determination of metal impurities in salts is more difficult, At the low powers we normally use, the presence of an alkali metal salt matrix can have an effect on sensitivity. This effect can be overcome by using a standard additions technique. A further problem is the effect of the sample matrix on the background.If we make exposures using water and then, say, 10% m/V sodium nitrate solution we tend to find an increase in intensity with the sodium nitrate that cannot be related to known impurities. This is due to stray light in the spectrometer and possibly also to continuum emission from the sodium. The wavelength profile for trace amounts of lead in 10% m/V sodium nitrate solution shows that the shift in background is approximately constant over the wavelength range used.The background shift is highly significant compared with the readings produced by our determinations. In other instances, where higher conccntrations are determined or greater sensitivity is available, the effect may be insignificant. The effect of alkali metal on the background is related to the anion of the salt being examined and not just to the cation, as we had originally supposed.Hence it is necessary to calibrate in the presence of the same salt as the sample under examination. Because of the wide linear range of the ICP it is necessary to use only a blank and a single standard. Many of the lead limits are very low, so we have started to consider chemical concentra- tion procedures.The problems with normal solvent extraction are that not all metals of interest are extracted and organic solvents cause an increase in background. Our approach is to use a back-extraction in such a way that all of the metals are transferred into an aqueous medium. A 90-ml aliquot is taken and an ammonium tetramethylenedithiocarbamate extraction is carried out using 1,1,2-trichlorotrifluoroethane as solvent.The extract is treated with 2 drops of concentrated nitric acid and the metals are then back-extracted into the remaining 10 rnl of the sample solution. The result is that the concentration of heavy metals is increased 10- fold while that of the alkali and alkaline earth metals is unchanged.This method has been applied to salts in which the lead limit is 2 p.p,m. Although we use the ICP mostly for trace analysis, we have also made a number of deter- minations of major constituents, e.g., copper and indium in copper indium selenide. Normally we take a 100-ml volume of the sample solution. Heavy Metals in Forensic Science D. A. Hickman In addition to the determination of the toxic metals arsenic, antimony, thallium, cadmium, mercury and lead in biological samples, the determination of heavy metals often plays an The Metropolitan Police Forensic Science Laboratory, 109 Larnbeth Road, Londovt, SE1 7LPJune, 19 79 DETERMINATION OF HEAVY METALS 187 important part in forensic investigations, for substrates such as glass, paint, soil, lead shot and gunshot residues. Poisoning by Thallium A notable investigation began in November 1971 when the manager of a photographic equipment firm in Bovingdon, Hertfordshire, became suspicious because two of his employees had died within the previous 6 months. Other workers in the factory had also been affected by a mysterious disease, the symptoms of which were nausea, vomiting, diarrhoea, giddiness and change of mood.Police attention was soon focused on the storeman a t the factory who seemed unaffected by the sickness involving his fellow workers, and this man, 24-year-old Graham Young, proved to have an encyclopaedic knowledge of poisons and their effects. A search of Young’s lodgings revealed a collection of some 70 chemicals, but the most startling find was a diary kept by Young in which he had described the administration, over a period of months, of doses of poison to various people.The effects of the poison were also noted. Young conceded during interviewing that the poisons he had used were antimony, as antimony sodium tartrate, and thallium, as the acetate. The initial involvement of this Laboratory was to examine the chemicals found in Young’s room, together with some found hidden near his place of work.All samples were subjected to a multi-element screen by d.c. arc - atomic-emission spectrography. The presence of antimony and thallium salts amongst the chemicals was established, From the post mortem of the second deceased victim some 40 specimens were submitted to the Laboratory for analysis.These, together with samples of blood, urine and sometimes hair from 16 other workers a t the factory, were screened for antimony and thallium by emission spectrography. Any positive findings were confirmed and quantified by atomic-absorption spectrometry. Thallium was found in all organs of the second deceased; some of the analytical results are listed in Table I. The presence of zirconium was identified in the urine of this victim; this was apparently contamination from the lubricant used on a catheter.TABLE I THALLIUM LEVELS FOUND IN THE SECOND DECEASED VICTIM Sample Thallium/ PLg 8-l Large intestine . . . . 120.0 Kidney . . .. . . 20.0 Liver . . . . . . . . 5.0 Muscle . . . . .. 5.0 Brain (grey) . . . . . . 10.0 Brain (white) .. .. 3.0 Sample Thallium/ PLg s1 Gall bladder ... . 1.1 Heart . . .. . . 13.3 +ng. .. .. .. 1.8 Sciatic nerve . . .. 1.0 Blood . . .. .. 3.4 Urine . . .. .. 6.0 The death of the first fatal victim had occurred several months previously, and only two samples were available for analysis. One was a kidney section taken at the time of his post mortem. This revealed a thallium concentration of 2.5 pg g-l, i.e., a factor of ten less than the concentration found in the second deceased’s kidney.The slide mounting procedure had involved treating the sample with formaldehyde - saline, dehydrating with alcohol and wash- ing out the fats with chloroform. A parallel preparation on the second deceased’s kidney resulted in a sample with a thallium level of 2.2 pg 8-1. Analysis of the cremation ash of the first deceased by emission spectrography showed it to contain 5 pg 8-l of thallium.Two other workers at the Bovingdon factory were found to have positive thallium levels in their blood or urine; one had 0.1 pg g-1 in his blood and 0.8 pg g-l in his urine, and the other 3 pg 8-l in his urine. These two victims also showed the characteristic loss of hair due to thallium poisoning. Graham Young’s poisoning activities had started a t the age of nine or ten when he stole poisons from his school laboratory and administered them to his school friends.At the age of fourteen he had attempted, using antimony, to murder his father, his sister and a school friend. For this he had been sentenced to 15 years in Broadmoor, but he had been released after 9 years and sent to a rehabilitation centre before starting work at Bovingdon.Young’s trial in 1972 lasted 2 weeks, and he was found guilty of two murders, two attempted murders and two charges of administering poison. He was sentenced to life imprisonment.188 SAC SILVER MEDAL Proc. Analyt. Div. Chew. SOC. Analysis of Lead Shot Shotgun pellets left after a shooting are often the only evidence immediately available, and chemical analysis of the shot may be informative.One such shooting occurred at the Upper Ham Road, Kingston, branch of Barclays Bank on November loth, 1976. A man aged about 25 years walked up to one of the cashier’s counters, levelled a sawn-off shotgun at the female cashier and demanded money. She handed over LZ 500, but seconds later the robber fired at point blank range at the security screen.The blast made a l$-in diameter hole in the screen, struck the 20-year-old cashier in the neck and chest and inflicted fatal injuries. The robber walked calmly from the bank and escaped. The evidence consisted of some 70 pieces of lead shot recovered from the victim’s neck, upper chest and lung, from the security glass and from the wall behind the cashier. Fibre and card wads recovered from the wound in the victim’s chest were identified as being of a type normally found in Eley cartridges of recent manufacture, and most probably from crimped paper cased Grand Prix or Trapshooting cartridges.The average shot size of the recovered shot, 1.2-1.3 grains, suggested a No. 7 shot, this size being more common for Trapshooting cartridges.A chemical analysis of the shot, and comparison with control samples of Grand Prix and Trapshooting shot, gave the results in Table 11, suggesting that a Grand Prix cartridge had been fired. In addition to arsenic and antimony, bismuth and copper have been established as useful elements for gunshot classification and discrimination. TABLE I1 ANALYSIS OF LEAD SHOT Mass of pellet/ Sample *% Antimony, yo Arsenic, yo Case sample .. . . .. 77.36 0.53 0.10 79.90 0.54 0.11 Eley Trapshooting No. 7 . . 85.08 2.26 0.42 80.12 1.80 0.41 83.24 0.64 0.14 Eley Grand Prix No. 7 . . .. 83.52 0.65 0.13 As a result of police investigations a suspect was apprehended 2 months after the murder. Although maintaining that the shooting was accidental, he made a confession and told the police that he had thrown the shotgun into the Thames at Hampton Court. Police frogmen recovered the gun, and it was examined at the Laboratory. The gun contained a fired cart- ridge in the right-hand barrel and an unfired cartridge in the left. More than 1 000 fragments of glass were recovered from the unfired barrel. All of the fragments analysed had the same refractive index as the security screen, and also matched its chemical composition. The cartridges in the gun were paper-cased Trapshooting No. 7. Further analysis of the shot in the remaining cartridge, that found at the scene of crime and that from cartridges found in the suspect’s house, showed that these samples were indistinguishable. The shot was of a Grand Prix specification, and apparently the manufacturers had used the wrong filling for this particular batch of cartridges. The author thanks Miss Eve Blacklock, who carried out much of the experimental work. Society for Analytical Chemistry Silwer Medal On the recommendation of its Honours Com- mittee, the Council of the Analytical Division, at its meeting on April 25th, awarded the seventh Research Officer at the Central Electricity Society for Analytical Chemistry Silver Medal to Dr. Derek Midgley Research Laboratories, Leatherhead, Surrey.

ISSN:0306-1396    

DOI:10.1039/AD9791600183

出版商:RSC    

年代:1979

数据来源: RSC

摘要:

June, 1979 OBITU 0 bituaries Mr. S . Dixon, Mr. R. Sinar and Mr. S . A. Price We deeply regret to announce the deaths of Mr. S. Dixon, a former Chairman of the Western Region, Mr. R. Sinar, a former Chairman of the North West Region, and Mr. S. A. Price, Hon- orary Secretary of the SAC from 1963-1967. Dr. W. T. Elwell The unexpected death of Bill Elwell, on the 15th February 1979, coming as it did just three weeks after the death of his wife Mary, was a great shock to his family and to his many friends.William Thomas Elwell, BSc, PhD, C.Chem, FRIC was born in 1912 at Windlestone, Co. Durham, and received his early education a t Cockton Hill School, Bishop Auckland. He joined Imperial Chemical Industries a t Billing- ham as a laboratory assistant in 1928 and, by spare-time study a t Constantine College, Middlesbrough, obtained his Associateship of the Royal Institute of Chemistry and his Fellowship, by examination, in that most difficult field, general analytical chemistry.Much later in life he obtained the degree of PhD a t I3irmingham University. At Billingham he worked for some years as Technical Officer analyst under H. N. Wilson, before being appointed, in 1955, Division Chief Analyst of the Metals Division of ICI, later Imperial Metal Industries, at Witton, Birming- ham.At that time the position was a very demanding one involving the continuation of the development and introduction of analytical procedures for the routine analysis of the “new metals,” principally titanium and zirconium. He applied himself to the task with charac- teristic energy and enthusiasm and it is for his work in this field that he will be best remembered.His efforts, and those of his colleagues, notably the late D. F. Wood, resulted in a series of publications; “The Analysis of Titanium and its Alloys,” was first published in 1956 and expanded in two subsequent editions in 1957 and 1959. In 1961 the book was extended to include the analysis of zirconium and published as “The Analysis of Titanium, Zirconium and their Alloys.” The scope of the work was extended still further to cover hafnium, niobium, tantalum, tungsten and their alloys, and the final volume, “Analysis of the New Metals,” was published in 1966.These books are internati-a.llv accepted works of reference on ’ARIES 189 the subject.Other books were “The Analyti- cal Chemistry of Molybdenum and Tungsten, ” published in 1971 and also co-authored by D. F. Wood, “The Analysis of Copper and its Alloys,” with I. R. Scholes, published in 1967, and “Atomic Absorption Spectrophotometry,” with J . A. F. Gidley. The last of these was the first text-book to be written on the subject, appearing in 1961 with a Second Edition in 1966.In addition he, with various co-authors, made over seventy contributions to scientific journals. In 1971 Bill Elwell was appointed IMI Chief Scientist, Chemistry and Analysis, a position held until his retirement in 1974. He gave unstintingly of his time and energy in his service to analytical chemistry. The following account of his activities is not com- plete but is indicative of his dedication.He was honorary lecturer in analytical chemistry at Birmingham University 1865-1975, external examiner for MSc in Instrumental Chemical Analysis a t Sheffield Polytechnic 197 1-1977, member of the Examination Board for the MChemA of the Royal Institute of Chemistry from 1974 until his death, Executive Committee member (and later Analyst Publications Committee Member) of The Analyst 1960-1978, Vice-president of the Society for Analytical Chemistry and of the Analytical Division of the Chemical Society 1967-1968 and 1974- 1975, and council member 1958-1959, 1965- 1966 and 1970-1977.He served on the Analytical Books and Monographs Committee 1974-1978, the Analytical Methods Committee 1963-1966, the Finance Committee 1970-1974, the Honours Committee 1974-1976 and the Group Liaison and Policy Committee from 1976 until his death.He was first Chairman of the Atomic Spectroscopy Group 1964-1965, Chair- man of the Midlands Section 1966-1967, Honorary Secretary of the International Sym- posium of Analytical Chemistry 1958 and Chairman of the 1969 International Symposium a t Birmingham. Between 1950 and 1974 he was a member of the British Chemical Standards Advisory Committee.In 1974 he was awarded the Gold Medal of the Analytical Division for outstanding services to analytical chemistry. He took great pleasure in editorial work and few, if any, of his staff left his office with their manuscript unscathed, however carefully it had been prepared. Punctuation was a passion with him and it was rumoured that he had a drawer in his desk full of commas, colons, hyphens and dashes.He was editorial adviser to AnaZytica Chimica Acta 1959-1974 and a member of the Editorial Advisory Board of The AnaZyst from 1969 until his death.190 NEW BRITISH STANDARDS PYOC. Analyt. Diu. Chem. SOC. Bill Elwell was essentially a classical analyst and, while ensuring that his laboratories were among the first to acquire, for example, XRF spectrometers and atomic-absorption equip- ment, instruments did not arouse his enthusiasm. This he reserved for the solution of a problem by a traditional chemical approach. Perhaps his chief personal characteristic was strength of will.No one could have guessed from his demeanour or performance that for the last fifteen years he had lived with the knowledge that his wife, to whom he was utterly devoted, was seriously ill.Only with his intimates would he discuss the subject and then only briefly and when invited to do so. Those of us who were privileged to work for him found that our successes met with quick and generous praise and our failures with understanding and encouragement. To our personal problems he lent a sympathetic ear; his advice was always sound and his help spontaneous and generous. Many young analysts have reason to be grateful for his interest and concern to assist them in every possible way. The Elwell Award was devised by him to encourage young analysts in the Midlands Region to stand on their feet and present a paper, usually for the first time, before a sympathetic audience. Outside analytical chemistry he took an active part in the Masonic movement and was a do-it-yourself man of well above average competence. He is survived by two daughters to whom our sympathies go in their double bereave- ment. D. M. PEAKE

ISSN:0306-1396    

DOI:10.1039/AD9791600189

出版商:RSC    

年代:1979

数据来源: RSC

摘要:

190 NEW BRITISH STANDARDS PYOC. Analyt. Div. Chem. SOC. Publications Received Measurement of Dissolved Oxygen. Michael L. Hitchman. Chemical A nalysis TroZuvne 49. Pp. xvi + 256. New York, Chichester, Brisbane and Toronto : John Wiley. 1978. Price Ll6.50. New Applications of Lasers to Chemistry. Edited by Gary M. Hieftje. A symfiosium sfionsored by the Division of Analytical Chemistry at the 175th Meeting of the American Chemical Society, Anaheim, CaZif., March 14-15, 1978.ACS Syyrzposiunz Series 85. Pp. xii + 244. Washington, D.C. : American Chemical Society. 1978. Price $23.50. Thin-layer Chromatography. Second Edition. Justus G. Kirchner. Techniques of Chemistry, Volume XIV. Pp. xxvii + 1137. New York, Chichester, Brisbane and Toronto : John Wiley . 1978. Price A42.50; $84.Estimating the Hazard of Chemical Sub- stances to Aquatic Life. Edited by John Cairns, Jr., K. L. Dickson and A. W. Maki. ASTM Special Technical Publi- cation 657. Pp. viii + 278. Philadelphia, Pa. : American Society for Testing and Materials. 1978. Price $19.50. Manual on Water. Fourth Edition. Edited by C. E. Hamilton. ASTM Special Technical Publication 442A. Pp.vi f 472. Philadelphia, Pa. : American Society for Testing and Materials. 1978. Price $29.50.June, 19 79 PUBLICATIONS RECEIVED 191 Statistical Method in Biological Assay. Third Edition. David J. Finney. Pp. xii + 508. London and High Wycombe: Charles Griffin & Company Ltd. 1978. Price j519. The Practicing Scientist’s Handbook. A Guide for Physical and Terrestrial Scien- tists and Engineers. Alfred J.Moses. Pp. xii + 1292. New York, Cincinnati, Atlanta, Dallas, San Francisco, London, Toronto and Melbourne: Van Nos- trand. 1978. Price L42.55. Ion-selective Electrodes in Analytical Chemistry. Volume 1. Edited by Henry Freiser. Pp. xiv + 439. New York and London: Plenum Press. 1978. Price j526.77. Treatise on Analytical Chemistry. Part 1. Theory and Practice.Second Edition. Volume 1 : Sections A-D; Analytical Chem- istry; Analytical Chemistry : Methodology; General Chemistry and Analytical Chemis- try; Solution Equilibria and Chemistry. Edited by I. M. Kolthoff and Philip J. Elving. Pp. xxx + 881. New York, Chichester, Bris- bane and Toronto: John Wiley. 1978. Price L41; $78.50. Annual Reports on Analytical Atomic Spectroscopy.Reviewing 1977. Volume 7. Edited by J . B. Dawson. Pp. x + 291. London : The Chemical Society. 1978. Price L17.50; 9535. Applications of Inductively Coupled Plasmas to Emission Spectroscopy. Edited by R. M. Barnes. 1977 Eastern Analytical Symposium. Pp. viii + 188. Phil- adelphia : The Franklin Institute Press. 1978. Price $18.95. Statistics. Edited by R. F. Hirsch. 1977 Eastern Analy- tical Symposium.Pp. viii + 308. Philadel- phia: The Franklin Institute Press. 1978. Price $21. Interpretation and Processing of Vibra- tional Spectra. Milan HorAk and Antonin Vitek. Pp. 414. Chichester, New York, Brisbane and Toronto : John Wiley. 1978. Price k18.50. Water Treatment Plant Design for the Practicing Engineer. Edited by Robert L. Sanks. Pp. x + 846. Ann Arbor, Mich.: Ann Arbor Science Publish- ers. Distributed by John Wiley. 1978. Price j525.20. Enzyme Labelled Immunoassay of Hor- mones and Drugs. Edited by S. B. Pal. Proceedings of the Inter- national Symposium on Enzyme Labelled Imm- unoassay of Hormones and Drugs, Ulnz, West Germany, July 10 and 11, 1978. Pp. xxvi + 475. Berlin and New York: Walter de Gruyter. 1978. Price DM130.Photometric Determination of Traces of Metals. General Aspects. Part I. Col- orimetric Determination of Traces of Metals. Fourth Edition. E. B. Sandell and Hiroshi Onishi. Chemical Analysis, Volume 3. Pp. xviii + 1086. New York, Chichester, Brisbane and Toronto : John Wiley. 1975. Price A32.40; $60. Sulfur in the Environment. Part I: The Atmospheric Cycle; Part I1 : Ecological Impacts.Edited by Jerome 0. Nriagu. Environmental Science and Technology Series. Part I, Pp. xiv + 464 + 8 page errata pamphlet; Part 11, xii + 482. New York, Chichester, Brisbane and Toronto: John Wiley. 1978. Price: Part I A23; Part I1 j524. Applications of High Performance Liquid Chromatography. A. Pryde and M. T. Gilbert. Pp. xii + 256. London: Chapman and Hall. Distributed by Halsted Press in the USA.1979. Price ,CIlO.FiO. Air Pollution Reference Measurement Methods and Systems. Proceedings of the International Workshop, Bilthoven, December 12-16, 1977. Edited by T. Schneider, H. W. de Koning and L. J. Brasser. Studies in Emironmental Science 2. Pp. viii + 168. Amsterdam, Oxford and New York: Elsevier. 1978. Price $35.55; Dfl80. L’Analyse de L’Eau. Eaux Naturelles, Eaux Rbsiduaires, Eau de Mer.Chimie, Phy s ico - chimie , B ac tbr io lo g ie , B iolo gie . J. Rodier. Pp. xxii + 1136. Paris: Dunod. 1978. Price Fr520.192 PUBLICATIONS RECEIVED Proc. Annlyt. Div. Chem. SOC. Standard Potential of the Silver - Silver Chloride Electrode. R. G. Bates and J . 13. Macaskill for Inter- national Union of Pure and Applied Chemistry, AnaIytical Chemistry Division, Commission on Electroanalytical Chemistry.Pp. 1701-1 706. Oxford, New York, Paris and Frankfurt: Pergamon Press. Quantitative Mass Spectrometry In Life Sciences 11. Proceedings of the Second International Symposium, held at the State University of Ghent, June 13-16, 1978. Edited by A. P. de Leenheer, R. R. Roncucci and C. van Peteghem. Pp. x + 502.Amster- dam, Oxford and New York: Elsevier. 1978. Price $48.45; llfl109. High Performance Liquid Chromato- graphy. Chemical Laboratory Practice. Heinz Engelhardt. Translated by George Gutnikov. Pp. xii + 248. Berlin, Heidelberg and New York : Springer-Verlag. 1979. Price DM64; $35.20. Contemporary Topics in Analytical and Clinical Chemistry. Volume 3. Edited by David M. Hercules, Gary M.Hieftje, Lloyd R. Snyder and Merle A. Evenson. Pp. xii + 306. New York and London: Plenum. 1978. Price L20.47. Ultratrace Metal Analysis in Biological Sciences and Environment. Edited by Terence H. Risby. X Symposium Sponsored by the Division of Analytical Chemistry a t the 174th Meeting of the American Chemical Society, Chicago, Illinois, August 29- 30, 1977. Advances in Chemistry Series 172. Pp.x + 264. Washington, D.C.: American Chemical Society. 1979. Price $36.50. Sixth Ceramic Chemists’ Conference (On Silicate Analysis) held on April 6 and 7, 1978, at the Hydro Hotel, Llandudno. The British Ceramic Research Association. Sfiecinl Publication No. 98. Pp. vi + 154. Stoke-on-Trent : The British Ceramic Research Association. 1979. Price LS. A Handbook of Decomposition Methods in Analytical Chemistry.Rudolf Bock. Translated from the 1972 Ger- man Edition by Iain L. Marr. Pp. xii + 444. Glasgow and London : International Textbook Co. Ltd. 1979. Price A19.75. Laboratory Handbook of Chromatographic and Allied Methods. Edited by 0. Mikes. Pp. 764. Chichester, New York, Brisbane and Toronto: Ellis Hor- wood. Distributed by John Wiley in Austra- lasia, South-east Asia, Canada, Europe and Africa and by Halsted Press in North and South America and the rest of the world.1979. Price j538.50. Polarized Light Microscopy. Walter C. McCrone, Lucy R. McCrone and John Gustav Delly. Pp. viii + 252. Ann Arbor, Mich. : Ann Arbor Science Publishers. 1978. Price Ll8.90; $33. Physical Methods in Modern Chemical Analysis.Volume 1. Edited by Theodore Kuwana. Pp. x + 320. New York, San Francisco and London: Aca- demic Press. 1978. Price $33. Mass Spectrometry of Natural Products. Plenary Lectures Presented a t the Inter- national Mass Spectrometry Symposium on Natural Products, Rehovot, Israel, 28 August-2 September 1977. International Union of Pure and Applied Chemistry (Organic Chemistry Division) in conjunction with Israel Academy of Sciences and Humanities and Israel Chemical Society.Edited by B. Sklarz. Pp. vi + 96. Oxford, New York, Toronto, Sydney, Paris and Frank- furt: Pergamon Press. 1978. Price $20. Atomic Absorption Spectroscopy. Second Edition. Morris Slavin. Chemical Analysis, Volume 25. Pp. xvi + 194. New York, Chichester, Brisbane and Toronto: John Wiley.1978. Price L14; $26. Potential Industrial Carcinogens and Mutagens. Lawrence Fishbein. Studies in Environmental Science 4. Pp. x + 534. Amsterdam, Oxford and New York: Elsevier. 1979. Price Dfl150. Monitoring Toxic Substances. Based on a symposium sponsored by the ACS Division of Industrial and Engineering Chemistry at the 174th meeting of the American Chemical Society, Chicago, Illinois, August 31, 1977.Edited by Dennis Schuetzle. ACS Symposium Sevies 94. Pp. xii + 290. Washington, D.C.: American Chemical Society. 1979. Price $26.50.June, 19 79 CONFERENCES AND MEETINGS 75 Years of Chromatography-A Historical Dialogue. Edited by L. S. Ettre and A. Zlatkis. Journal of Chromatography Library, Volume 17. Pp. xiv + 502. Amsterdam, Oxford and New York : Elsevier.Distributed by Elsevier North Holland in the USA and Canada. 1979. Price Dfl112. Recent Developments in Chromatography and Electrophoresis. Proceedings of the 9th International Symposium on Chro - matography and Electrophoresis, Riva del Garda, 15-17 May 1978. Edited by Albert0 Frigerio and Leika Renoz. Chromatography Symposia Series, Volume 1. Pp. x + 357. Amsterdam, Oxford and New York : Elsevier. Distributed by Elsevier North Holland in the USA and Canada. 1979. Price $58.50; DA120. Analytical Laser Spectroscopy. Edited by Nicolb Omenetto. Chemical Analy- sis, Volume 50. Pp. xiv + 550. New York, Chichester, Brisbane and Toronto : John Wiley. 1979. Price k24.50; $45. Handbook of Analytical Control of Iron and Steel Production. T. S. Harrison. Ellis Horwood Series in Analytical Chemistry. Pp. 602. Chichester : Ellis Horwood. Distributed by John Wiley in Australasia, South-East Asia, Canada, Europe and Africa and by Halsted Press in North and South America and the rest of the world. 1979. Price k37.50. 193

ISSN:0306-1396    

DOI:10.1039/AD979160190b

出版商:RSC    

年代:1979

数据来源: RSC

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June, 19 79 CONFERENCES AND MEETINGS 193 Conferences and Meetings XXI Colloquium Spectroscopicurn Inter- nationale J u l y 1-6, 1979, Cambridge This meeting, which includes the 8th Inter- national Conference on Atomic Spectroscopy, will be held in various buildings of the Uni- versity, delegates being housed in seven of the colleges. Over 250 papers and 100 posters will be presented in 28 symposia and two poster sessions and among the speakers will be the following: K.M. Aldous, R. M. Barnes, Y . I. Belyaev, P. W. J. M. Boumans, L. S. Birks, R. F. Browner, R. Castaing, C. L. Chakrabarti, D. T. Clark, 111. J. Colles, A. Danielsson, H. J. Dussel, W. G. Fately, K. Fuwa, L. de Galan, J, Grasselli, P. Hannaford, E. I. Hamilton, R. Herrman, G. M. Hieftje, R. Jenkins, P.N. Keliher, G. F. Kirkbright, J. L. Koenig, K. Laqua, D. A. Long, H. Massman, H. R. Morris, G. H. Morrison, N. Omenetto, J. M. Ottaway, P. E. Paus, T. C. Rains, R. 0. Scott, N. Sheppard, R. Stephens, V. Sychra, G. Tessari, A. Townshend, J. Van Loon, J. B. Willis, D. H. Williams, J. D. Winefordner and K. Yasuda. In addition, a very extensive Social Programme has been organised.The address of the conference secretary is Secretariat, XXI CSI/Sth ICAS, P.O. Box 109, Cambridge, CB1 2HY. Automation in Industrial and Clinical Chemistry J u l y 16-18, 1979, London This Conference will be held at the City Univer- sity, London, and will include Keynote Lectures by Professor M. Bonner Denton (University of Arizona), Dr. F. L. Mitchell (Clinical Research Centre, Harrow) and Dr.R. W. Arndt (Mettler Instruments AG, Switzerland). Further details from Beverly Humphrey, Scientific Symposia Ltd., UTP House, 33-35 Bowling Green Lane, London, EC1 ODA. Aids to Trace Organic Analysis Sefitember 4-7, 1979, Guildford This Third International Bioanalytical Forum, which will be held at the Wolfson Bioanalytical Centre in Guildford, is intended to provide an exchange of know-how amongst analysts with interests ranging from pollutants to drugs in blood.Topics, with emphasis on sample handling, include ligand, enzymic and other approaches to drug assay, automatic procedures, problems in obtaining valid results, and residues and other trace pollutants. For details, contact the Wolfson Bioanalytical Centre, University of Surrey, Guildford, Surrey, GU2 5XH.194 CONFERENCES AND MEETINGS Proc.AnaZyt. Div. Chew. soc. Computer Based Analytical Chemistry (COBAC) September 24-28, 1979, Portorox, Yugoslavia The above conference is sponsored by the Federation of European Chemical Societies and will be divided into the following sections: “Fundamentals of Computerisation of Chemical Analysis” ; “Principles and Problems of Com- puter-based Instruments” ; “Analytical In- formation Systems” ; and “Special Topics in Computer-based Analytical Procedures.” Details of the Conference can be obtained by writing to Professor Dr.D. Hadzi, Kemijski Institut Borisa Kidrica p.0. , Hajdrihova 19, Yu- 61 00 1 Ljubljana, Yugoslavia. International Winter Conference 1980 on Developments in Atomic Plasma Spectro- chemical Analyses January 7-11, 1980, San Juan, Puerto Rico An international conference featuring develop- ments in atomic plasma spectrochemical analyses with inductively coupled (ICP), micro- wave (MIP, MWP) and d.c.plasma (DCP) discharges will be held at the Hilton Condado Beach and La Concha Hotels and the Con- vention Center in San Juan. Papers describing original work on appli- cations, fundamentals and instrumentation developments of atomic plasmas (ICP, MIP, DCP) in spectrochemical analysis will be presented in general and invited symposia.Special applications symposia organised and chaired by recognised experts will be held in topical areas which include : Agriculture and Food ; Biology, Medicine, and Industrial Hygiene; Geology and Mining; Energy Pro- duction and Energy-related Materials ; Environ- mental Monitoring ; Metals and Industrial Chemicals ; Oceanography ; Petroleum Products and Fuels; and Water Quality Monitoring.Other special symposia will feature recent developments in sample treatment and intro- duction, element-specific plasma detectors for chromatography, and new plasma generators , sources, and spectrometer systems.The following Plenary lectures will be presented : S. Greenfield (England) , “Detection Limits and Other Figures of Merit in ICPES”; P. W. J. M. Boumans (Netherlands), “ICP: A Polyhedron with Many Interfaces” ; L. de Galan (Netherlands), “Novel Possibilities of MIP and ICP Sources” ; and R. L. Watters, Jr. (Washing- ton), “Sampling and Analysis Strategies for Plasma Spectrochemical Analysis.’’ The invited lectures will be: G.R. Kornblum (Netherlands), “Preliminary Results with a Low Consumption Argon ICP” ; G. Kirkbright (England), “Dry Aerosol Analyte Presentation and Excitation Mechanisms in ICP”; K. Ohls (Germany), “Analysis of Liquid, Solid, and Gaseous Samples Using a High Power Nitrogen - Argon ICP System”; R. F. Browner (Atlanta), “Recent Studies with Sample Introduction into the RFICP”; and M.I. Boulos and R. M. Barnes (Sherbrooke/Amherst), “Induction Plasma Modelling-State of the Art.” Authors of oral or poster papers for general and specialised symposia are requested to submit titles of their contributions and a 50-100 word preliminary abstract prior to July 1, 1979. Presentations will be for 15 minutes with 5 minutes of discussion, although longer times will be arranged on request.An extended abstract will be required by October 1, 1979. The full conference papers will be refereed and published by Heyden & Sons, Inc., following the conference. Those interested should submit abstracts and write for registration and hotel reservation information to Winter Conference 1980, ICP Information Newsletter, Chemistry-GRC Tower I, University of Massachusetts, Amherst, Mass. 01003.USA. J. Heyrovsky Memorial Congress on Polar o grap hy August 25-29, 1980, Prague This Congress will take place from August 25th to 29th, 1980 (not from the 18th to the 22nd, as was announced originally). The Congress is to be organised on the occasions of the 90th anniversary of the birth of Professor Jaroslav Heyrovskf, Nobel Laureate in Chemistry, 1959, and of 30 years since the foundation of the Polarographic Insti- tute which now forms part of the J. Heyrovsky Institute of Physical Chemistry and Electro- chemistry of the Czechoslovak Academy of Sciences. The aim of the Congress is to survey the present state of polarography and related methods in the fields of basic research, con- temporary instrumental techniques , analytical chemistry and applications in industry, biology, medicine and environmental science. For detailed information, write to the Secretariat of the J. Heyrovsky Memorial Congress on Polarography, Vlasska 9, 118 40 Praha 1 - MalA Strana, Czechoslovakia.

ISSN:0306-1396    

DOI:10.1039/AD9791600193

出版商:RSC    

年代:1979

数据来源: RSC