摘要:

Proceedinas - of the Analytical Division 0.fThe Chemical SocietyCONTENTS717273757592979799100Annual General Meeting of theAnalytical DivisionReports of MeetingsAnalysts or Analytical Scientists?Summaries of Papers‘Isotachophoresis and lsoelectricFocusing‘Equipment N ewsCoursesConferences and MeetingsPublications ReceivedAnalytical Division DiaryVolume 14 No 4 Pages 71-100 April 197PADSDZ 14(4)71-lOO(1977)ISSN 0306-1 396April 1977PROCEEDINGSOF THEANALYTICAL DIVISION OF THE CHEMICAL SOCIETYOfficers of the Analytical Divisionof the Chemical SocietyPresidentD. W. WilsonHon. SecretaryP. G. W. CobbSecretaryMiss P. E. HutchinsonHon. Treasurer Hon. Assistant SecretariesJ. K. Foreman D. I. Coomber, O.B.E.; D.C. M. Squirrel1Editor, ProceedingsP. 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, Publications Sales Office, Blackhorse Road,Letchworth, Herts., SG6 1 HN.Non-members can only be supplied with Proceedings as part of a combined subscription with The Analystand Analytical Abstracts.Q The Chemical Society 1977CS ATOMIC SPECTROSCOPY GROUPinvite applications for the1977 RANK HILGER SPECTROSCOPY PRIZEThe successful candidate will receive a prize to the value of f75, part of which is tobe used for the purchase of a book(s) for presentation at the Group's AGM.Theaward will be judged on the basis of the candidate's contribution to analyticalatomic spectroscopy. The work need not be theoretical but could cover applic-ations, instrumental modification, accessories, improvements in technique or datahandling. The contribution need not have been published and candidate's wisheswith respect to publication will be respected.Intending candidates should (1) be under 30 years of age on December 31st,1977; (2) be resident in the United Kingdom; (3) submit, before May 31 st, 1977,a summary of about 500 words, describing their contribution to the theory orpractice of atomic spectroscopy. The summary should be endorsed by a seniormember of the establishment in which the candidate is employed.Applications should be addressed to the Honorary Assistant Secretary, AtomicSpectroscopy Group, Analytical Division, The Chemical Society, Burlington House,London, WIV OBN

ISSN:0306-1396    

DOI:10.1039/AD97714FX013

出版商:RSC    

年代:1977

数据来源: RSC

摘要:

April, 1977 PUBLICATIONS RECEIVED 99Analytical Division Diary, continuedMay, continuedThursday, 19th, 2 p.m.: MiddlesbroughNorth East Region on “Analytical Techniquesin the Steel Industry.”“Organisation of BSC Research,” by F.Fitzgerald.Followed by several short papers coveringaspects of analytical development, and atour of the Chemical Services, Library andInformation, Mathematics and ComputingDepartments.BSC Research Laboratories, Ladgate Lane,Middlesbrough, Cleveland.Thursday, 26th, 2.30 p.m.: LondonSouth East Region and Chromatography andElectrophoresis Group on “-1nalysis ofIndustrial Essential Oils.”“The Reproducible Fingerprinting of Essen-tial Oils by Temperature-programmedGLC,” by A. M. Humphrey.“Some Practical Experience in the Use ofReporting Integrators in Essential OilAnalysis,” by D.0. Moyles.Paper by M. J. Milchard.Chelsea College, University of London,Manresa Road, London SU73 6LXAnalytical Division DiaryAPRILThursday, 21st, 2.30 p.m.: LondonBiological Methods Group.Discussion on “The Compendium of Standardsfor Biological Medicinal Products,” pre-sented by a panel of speakers from theDepartment of Health and Social Securityand the National Institute of BiologicalStandards and Control, headed by J. A.Holgate.National Institute for Biological Standardsand Control, Holly Hill, Hampstead,London, N.W.3.Friday, 22nd, 4 p.m.: PooleWestern Region.“Parts per Thousand Million,” by B. Poole.BDH Staff Club, Poole, Dorset.MAYTuesday and Wednesday, 3rd and 4th:LondonAnalytical Division on “Research and De-velopment Topics in Analytical Chemistry.”Tuesday, 3rd-“Some Applications of Optoacoustic Spectro-scopy to Solid Samples,” by B. C. Beadle,M. J. Adams and G. F. Kirkbright.“The HPLC of Bleomycins,” by C. Williams.“The Analysis of Carbohydrates by HighPerformance Liquid Chromatography, ” byA. D. Jones.“Extraction and Separation of Metal Ionsby Foam-supported Reagents,’, by M.Maloney, G. J. Moodyand J. D. R. Thomas.“Two-dimensional Light Element Profilingwith the Nuclear Microprobe,” by J.Huddleston and T. B. Pierce.“Comparison of the Determination of Leadin Blood by Delves Cup and CarbonFurnace Atomic-absorption Spectrometry, ”by S. Sabet, J . M. Ottaway and G.S. Fell.“Some Applications of GLC in the Investig-ation of the Relationship between Physio-logical Stress and Physical Activity,” byL. S. Bark, R. Gravelling and H. Thomason.“Continuous On-line Measurement Tech-niques for Use with Ion-selective Electr-odes,,’ by W. F. Farrell, M. J . Connolley,R. N. Cockroft, B. Fleet and P. B. Stock-well.Wednesday, 4th-“Photometric Titration of Selected TransitionMetal Ions with Cyanide, ” by RussellMurphy.“The Identification of Sulphonamides andtheir Metabolites by Pyrolysis/GC/MS, ” byJ . A. Slack and W. J . Irwin.“The Determination of Sulphur Compoundsof Biological and Medical Importance byMolecular Emission Cavity Analysis,” byM. Q. Al-Abachi.“Some Investigations into the Electroanaly-tical Chemistry of Selenium,” by S.Forbes.“Sub-cellular Mercury as Determined byTEM - X-ray Microanalysis,” by W. R.Simpson.“Further Observations on a Binuclear Titan-ium(IV/III) Complex,” by ShamsalddinMohammed.“The Use of PVC Membrane Type CalciumElectrodes for Continuous Automatic Ana-lysis,” by C. R. Loscombe and J. A. W.Dalziel.Chemistry Department, Chelsea College, Man-resa Road, London SW3 6LX.Thursday, 5th, 2.30 p.m. : HoddesdonEast Anglia Region on “Methods in Pharma-ceutical Analysis.“The Application of Fourier Transform NMRin Pharmaceutical Research Analysis, ” byD. J. Kennedy.“Experiences in Problem Solving in Pharma-ceutical Analysis,” by D. J. Evans.“The Use of HPLC in Pharmaceutical Ana-lysis,” by P. Raven.Merck Sharp and Dohme Ltd., HertfordRoad, Hoddesdon, Herts.Tuesday, 17th, 11.15 a.m.: LondonJoint Pharmaceutical Analysis Group on“Short Original Papers Concerned withPharmaceutical Analysis.”Pharmaceutical Society of Great Britain, 1Lambeth High Street, London SE1 7JN.Midlands Region and Atomic SpectroscopyGroup, jointly with the SpectroscopyGroup of the Institute of Physics on“Instrumental Aspects of Atomic Spectro-scopy.“A History of Flame Analysis,” by S. L.Bogdanski.“A Study of Atomic Line Profiles fromSpectral Sources by Scanning Interfero-metry,’, by G. F. Kirkbright.“The Use and Versatility of HolographicGratings in Direct Reading Spectrographs, ’by J. B. Baird.“Nebulisers and Inductively Coupled Plasmas-Fact or Fiction?” by S. Greenfield.Physics Lecture Theatre, The Universityof Warwick, Coventry.icontinued inside back coverWednesday, 18th, 2.15 p.m.: CoventryPrinted by Heffers Printers Ltd Cambridge Englan

ISSN:0306-1396    

DOI:10.1039/AD97714BX015

出版商:RSC    

年代:1977

数据来源: RSC

摘要:

Vol. 14 No. 4 April 1977 Proceedings of the Analytical Division of the Chemical Society Annual General Meeting of the Analytical Division The fifth Annual General Meeting of the Analytical Division of the Chemical Society was held at 2.30 p.m. on Thursday, March 17th, a t the Royal Station Hotel, Station Road, York. The Chair was occupied by the Presi- dent, Mr. D. W. Wilson, MSc, CChem, FRIC.The Report of the Council for the year ending March, 1977, was presented by the Honorary Secretary and adopted. The Scrutators, Mr. P. J. Burnill and Mr. D. F . Griffiths, reported that the following had been elected officers for the coming year- President-D. W. Wilson, MSc, CChem, FRIC. Past Presidents serving on the Council- G. W. C . Milner, A. A. Smales, T. s. West and C.Whalley. Vice-Presidents-H. E. Brookes, H . Egan and J. Whitehead. Honorary Treasurer- J. K. Foreman. Honorary Secretary-P. G. W. Cobb. Honorary Assistant Secretaries--D. I. Coomber (Programmes Secretary) and D. C. M. Squirrell. Other Members of Council-The Scrutators fhrther reported that 620 valid ballot papers had been received and that votes had been cast Presentation of the twelfth SAC Gold Medal by the President, MY.D. W. Wilson, to Professor T . S. West ( L ) . in the election of Ordinary Members of Counci as follows-R. Belcher, 413; E. Bishop, 324; D. Thorburn Burns, 264; C. J. Keattch, 173; J. M. Ottaway, 361; J . E. Page, 371; G. E. Penketh, 326; T. B. Pierce, 312; R. Sawyer, 360; F. C. Shenton, 365. Presentation of the second Distinguished Service Award by the President to Dr.D. C. Garratt (R). The President declared the following to have been elected Ordinary Members of Council for the ensuing 2 years-R. Belcher, J . M. Ottaway, J . E. Page, G. E. Penketh, R. Sawyer and F. C. Shenton. D. Betteridge, G. B. Crump, W. T. Elwell, S. Greenfield, D. I. Reesand D. Simpson, having been elected members of the Council in 1976, will, by the Rules of the Division, remain members of the Council for 1977.D. C. Garratt (Chairman of the Analytical IWethods Committee), F. J. Bryant (Chairman of the Analytical Abstracts Committee), H. J . Cluley (Chairman of The Analyst Publications Committee), J. B. Dawson (Chairman of the Books and Monographs Committee), J . D. R. Thomas (Chairman of the Programmes Committee), J.W. Ogleby (Chairman of the North West Region), A. M. Ure (Chairman of the Scottish72 REPORTS OF MEETINGS Proc. Analyt. Div. Chem. SOC. Region), G. J. Dickes (Chairman of the Westerrt Region), A. Townshend (Chairman of the Mid- lands Region), H. Hughes (Chairman of the North East Region) and W. H. C. Shaw (Chairman of the South East Region) will be ex oflcio members of the Council for 1977.D. Simpson (Chairman of the East Anglin Region) is an elected member of Council. A proposed amendment to the Rules of the Division was passed ; as a result, in the election of officers nominations will be acceptable if they bear the signatures of 50 members of the Division. At the Informal Dinner held at the Royal Station Hotel, York, in the evening, the President presented the twelfth SAC Gold Medal to Professor T. S. West and the second Analytical Division Distinguished Service Award to Dr. D. C. Garratt. Biographies of the two recipients were published in the March issue of Proceedings.

ISSN:0306-1396    

DOI:10.1039/AD9771400071

出版商:RSC    

年代:1977

数据来源: RSC

摘要:

72 REPORTS OF MEETINGS Proc. Analyt. Div. Chem. SOC. of Committee-Mr. L. W. Bell, Dr. L. C. Ebdon, Mr. G. Himsworth, Mr. F. C. Shenton, Dr. A. A. Smales and Mr. J. Whitehead. Mr. C. N. Bell and Mr. J. Vallance were appointed as Honorary Auditors. Reports of Meetings North West Region The fifty-third Annual General Meeting of the Region was held a t 6.30 p.m. on Friday, January 21st, 1977, a t the University, Salford.The Chair was taken by the Chairman of the Region, Dr. L. S. Bark. The following office bearers were elected for the forthcoming year : Chairman-Mr. J . W. Ogleby. Vice-Chairman -Mr. G. B. Crump. Honorary Secretary-Mr. G. Davison, Research Department, Kodak Ltd., Acornfield Road, Kirkby, Lancs. Honorary Treasurer-Mr. T. Hodson. Members of Committee-Dr.J. M. Bather, Mr. E. C. Conchie, Mr. S. T. Holding, Mr. G. Hooke, Mr. B. Taylor and Dr. P. R. Wood. Mr. M. McDonnell, Mr. A. C. Bushnell and nlr. J. Cottam were appointed as Honorary Auditors. North East Region The eleventh Annual General Meeting of the Region was held a t 7.15 p.m. on Wednesday, January 26th, 1977, at the Golden Eagle Hotel, Thornaby-on-Tees. The Chair was taken by the Chairman of the Region, Mr.F. E. Harper. The following office bearers were elected for the forthcoming year : Chairman-Dr. H. Hughes. Vice-Chairman-Dr. C. Woodward. Honorary Secretary-Mr. D. F. Griffiths, Davy Powergas Ltd., Research and Development Department, Bowesfield Lane, Stockton-on-Tees, TS 18 3HA. Honorary Treasurer-Dr. J. Newham. Honorary Assistant Secretary-Mr.P. J. Burnill. Members Microchemical Methods Group The thirty-third Annual General Meeting of the Group was held a t 6.15 p.m. on Tuesday, January 25th, 1977, in the Linnean Society, Burlington House, London, W.l. The Chair was taken by the Chairman of the Group, Mr. R. Sawyer. The following office bearers were elected for the forthcoming year : Chairman- Mrs. D. Butterworth. Vice-Chairman-Mr.R. Sawyer. Honorary Secretary-Mr. P. R. W. Baker, Chemical Research Laboratory, Well- come Research Laboratories, Langley Court, Beckenham, Kent, BR3 3BS. Honorary Trea- surer-Mr. A. C. Thomas. Honorary Assistant Secretary-Mr. B. T. Saunderson. Members of Committee-Mr. M. Cottrell, Mr. G. C. Dickson, Dr. M. A. Leonard, Dr. D. J. Mowthorpe, Dr. D. A. Pantony and Mr.C. A. Watson. Mr. H. Childs and Dr. H. I. Shalgosky were re- appointed as Honorary Auditors. Biological Methods Group The thirty-second Annual General Meeting of the Group was held at 6.30 p.m. on Thursday, November 18th, 1976, in The New Savoy Tavern, Savoy Street, London, W.C.2. The Chair was taken by the Chairman of the Group, Mr. F. W. Webb. The following office bearers were elected for the forthcoming year: Chair- man-Dr.J. A. Holgate. Vice-Chairman-Dr. B. A. Wills. Honorary Secretary-Mr. V. J. Birkinshaw, The Boots Co. Ltd., Research Department, Thoresby Street, Nottingham, NG2 3AA. Honorary Treasurer-Mr. D. J. N. Hossack. Honorary A ssistant Secretary-Miss F. N. Mulholland. Members of Committee- Dr. M. E. Duncan, Miss A. Jones, Dr. L. Single- ton, Dr.D. A. Thomas and Mr. F. W. Webb. Dr. J. H. Hamence and Dr. M. Parkes were re- appointed as Honorary Auditors. Electroanalytical Group The seventh Annual General Meeting of the Group was held at 2.15 p.m. on Wednesday, December 8th, 1976, a t Imperial College, South Kensington, London, S.W.7. The Chair was taken by the Chairman of the Group, Mr. A. E. Bottom. The following office bearers were elected for the forthcoming year : Chairman -Dr.W. F. Smyth. Vice-Chairman-Dr. P. 0. Kane. Honorary Secretary-Dr. B. J.April, 1977 ANALYSTS OR ANALYTICAL SCIENTISTS ? 73 Birch, Unilever Research Laboratory, Port Sunlight, Wirral, Merseyside. Honorary Treasurer-Dr. A. G. Fogg. Members of Committee-Mr. A. E. Bottom, Mr. I. Davidson, Dr. B. Fleet, Dr. T. Ryan, Dr.J. D. R. Thomas and Dr. H. Thompson. Dr. J. A. W. Dalziel and Mr. J . H. Glover were re-appointed as Honorary Auditors. Education and Training Group The sixth Annual General Meeting of the Group was held at 2 p.m. on Thursday, December 2nd, 1976, at the Polytechnic of North London, Holloway Road, London. The Chair was taken by the Chairman of the Group, Dr. J. B. Headridge. The following office bearers were elected for the forthcoming year : Chairman- Professor D.Thorburn Burns. Vice-Chairman -Dr. J. G. Pritchard. Honorary Secretary- Dr. N. T. Crosby, Laboratory of the Govern- ment Chemist, Cornwall House, Stamford Street, London, SE 1 9NQ. Honorary Treasurer -Mrs. M. I. Arnold. Members of Committee- Dr. G. s. Davy, Mr. H. Finlay, Dr. J . B. Headridge (ex oficio), Dr.J . Parsonage, Dr. W. I. Stephen, Mr. J . D. Wheatley and Dr. W. J . Williams. Mr. J . Bassett and Dr. J. A. W. Dalziel were re-appointed,as Honorary Auditors. J o i n t P ha r rnaceu t ica I An a I ysi s Group The seventh Annual General Meeting of the Group was held at noon on Wednesday, January 19th, 1977, at the Pharmaceutical Society of Great Britain, 1 Lambeth High Street, London, SE1 7 J N . The Chair was taken by the Chair- man of the Group, Mr. s. C. Jolly. The follow- ing office bearers were elected for the forth- coming year: Chairman-Mr. S. C. Jolly. Honorary Secretary-Miss I. Ladden, British Pharmacopoeia Commission, 8 Bulstrode Street, London, W 1M 5FT. Members of the Covnvnittee -Mr. E. Addison, Mr. J. F. Chissell, Mr. D. R. Crudgington, Mr. J . C. Deavin, Mr. J . E. Fairbrother, Mr. D. H. Mitchell, Mr. G. F. Phillips, Mr. W. H. C. Shaw (nominated by the Chemical Society) and Dr. D. C. Garratt (nominated by the Pharmaceutical Society).

ISSN:0306-1396    

DOI:10.1039/AD9771400072

出版商:RSC    

年代:1977

数据来源: RSC

摘要:

April, 1977 ANALYSTS OR ANALYTICAL SCIENTISTS ? 73 Analysts or Analytical Scientists? The following is an account of the Retiring Chairman’s Address given by Dr. L. S. Bark following the Annual General Meeting of the North West Region a t the University of Salford on January 21st. In view of the fact that Proceedings for January (p. 1) reported at length upon training in analytical chemistry it is interesting that Dr.Bark should have chosen to talk about the same subject when asked over a year ago for a title for his Retiring Chairman’s Address. Dr. Bark first remarked upon his having been the only academic to have become Chairman of the local committee throughout its 52-year history, and he said that in that time there had been many changes. Once, all scientists had performed their own analyses, and one can read in old journals some fierce accusations that the very science of some people was at fault because their analytical techniques were suspect.Yet, despite the public airing of doubts at that time, analytical chemistry was held in high regard. Analytical chemistry has since become a specialisation, and most analyses are made by people who have no real con- nection with the materials to be analysed, but are concerned only with giving answers, often for a fee.Under these circumstances, analysts are often judged on the basis of their ability to come up with the answers that fit the theories of the people who submit materials for analysis . . . not necessarily the correct results, but the desired results! Since that happened, the status of the profession has been in decline.These range from those who will follow a procedure explicitly without comment or concern, to those who can handle decisions that include more than one variable. All of these people look for their successful continuance to the hope of specific reagents. They hope one day to have a laboratory where a shelf marked “Elemental Analysis’’ is divided into about 110 compart- ments, and in compartment 13 there is a reagent for aluminium that will give the aluminium content of whatever it may be applied to, in acidic solution, alkaline solution or even in solids.On the shelf marked “Organic Analysis,” in the appropriate compartment, there will be a The profession is also diluted with people who might be termed “determinators.”74 Proc.Analyt. Div. Chem. SOC. reagent for carbonyl groups that will identify and determine carbonyl no matter how it occurs . . . Anybody who does not believe this has not been reading manufacturers’ literature or encountering some of the papers submitted for publication. One can buy kits that promise to perform do-it-yourself analyses of wonderful precision, especially upon blood.It is not the question of training these people that is to be considered here. Twenty or thirty years ago, there was a species of analytical chemist, already rare then and even rarer now, who had a mixture of theory and experience heavily weighted in favour of the latter attribute, and whose rewards must have been wholly spiritual (whoever heard of a new patented method of analysis or a new company floated in order to develop an analytical technique?).We need them back, because chemistry, which may be likened to a cake whose slices represent organic chemistry, inorganic chemistry and so on, has to rest upon a firm foundation if it is not to fall apart, and that firm foundation is analytical chemistry, as it provides all the data upon which all the other branches depend and without it no significant progress can be made in any other branch of chemistry. The teaching bodies are aware oi the importance of analytical chemistry, yet they con- stantly face two questions from industry, which seem to deny this awareness.They are: “Why do the universities and polytechnics not train chemists for ‘Industry’,’’ and, “Why do graduates only learn the wrong techniques?” The trouble is, nobody in industry or in the teaching institutions knows precisely what the questions mean.The analytical chemistry research group at Salford University has sent students into all types of industries and has examined very carefully what they had done. It must be concluded that there are no means of correlating what they had been asked to do with any possible course of training.Industry is so many things that we cannot know what “Industry” is! To examine this question, we must assess the range of techniques available in any teaching institution. For example, the techniques of analysis include various techniques of separation ranging from those capable of separating a few nanograms to procedures used on an industrial scale.The cost of specialised equipment on which training depends can range from a few pounds to several thousands of pounds. In the present financial climate one feels the pressure to train in techniques that are relatively cheap. Then, if we think of measurement techniques, such as potentiometry, electro- deposition, coulometry, polarography, anodic voltammetry, kinetic methods, mass spectro- metry, X-ray fluorescence spectrometry, NMR, IR, what is the price? Which can we leave out? In the time available some must be treated superficially or not at all-which part of Industry will suffer ? Among the growth industries at present are those which deal with solid-state and bio- medical matters and agriculture.The first requires materials science and, to answer its problems, one needs emission spectroscopy, X-ray fluorescence, flame emission, atomic absorption, vacuum-spark mass spectrometry, activation analysis, isotope-dilution analysis, electroluminescence, Mossbauer spectrometry, electron-probe analysis and much more besides.In 1950 one hospital laboratory in Connecticut performed 35 “routine tests,” by 1960 these had increased slightly, to 38 tests; by 1970 the number had doubled, and by 1952 they were performing 100 tests which they called “routine,” even when a test that was needed perhaps only once every year was involved, and there are over 75 separate skills required to do these “routine” quantitative analyses. Agricultural science is generally concerned with two things: how to make things grow and how to prevent things from being destroyed.As the very nature of the samples varies, enormous numbers of particular tests are needed for agricultural studies. Here we meet the problems connected with rapid determinations and with storage of information, which indicates another area where training is required for a modern graduate. Graduates may move into any of these fields; which needs to be emphasised more than the others? There is only a finite amount of time available for an expanding subject.People talk about inter-disciplinary approaches to the training of new scientists, but the industries which suggest this simply do not accept how many universities work. Each discipline in a university is concerned to retain its identity, and a chemist likes to think he knows more about chemistry and the teaching of chemistry than, say, a physicist knows, and the physicist is tarred with the same brush.Most work which crosses boundaries is ANALYSTS OR ANALYTICAL SCIENTISTS ? Why do graduates learn the wrong techniques? In biomedical analysis, one can find some revealing statistics.April, 1977 ’ ISOTACHOPHORESIS AND ISOELECTRIC FOCUSING 75 tackled by means of a multi-disciplinary approach, and it is likely that problems involving analysis could benefit from a similar approach.Too often the analytical chemist has been called in at the end of a 3-year project and asked to produce results in a few hours. He ought to be part of the research project from the beginning, but this may mean that we need analytical scientists whose function is something like that of an insurance broker, and who, at any particular juncture, can say, “Your best approach is NMR, or mass spectroscopy, or whatever,” because if the country produces only specialists they will tend to see problems in terms of their specialisation only, and in many instances will try to solve a problem by only one technique, not necessarily the best combination of techniques.We start with the broad base of chemistry, but what then? Do we train people how to calculate, how to decide when and whether to change to automation? Do we try to find a way to train people to find out whether an analysis needs to be done? An analytical chemist who is not just a results producer should be able to say whether the question which the questioner is posing is irrelevant, and that he should ask a different question, or request a different answer.The universities cannot undertake to train specialists only, as it does not seem to matter how many techniques a student is taught because the industry which takes him will always use the (n + 1)th technique. It must be emphasised that to make the kind of person industry seems to ask for, much longer courses would be required.Analytical chemistry should mainly be a postgraduate course, and no one should be allowed to enter such a course who has not already shown a high degree of common sense. The profession would also benefit from a departure from the “PhD or equivalent” jargon, because all that the “or equivalent” means is that somebody is going to be paid less.Among non-analytical people, there is sometimes too little appreciation of how much work is involved in professional examinations, MChemA for example. They often have no concept of how broadly based the qualification is, or the depth to which the students must examine the samples. But how do we plan the training? Do we teach problem solving? In question time, Mr.C. Whalley said that he felt that much of what had been said was correct and that Dr. Bark was right when he said that what was needed was someone who thinks, not merely an expert in a narrow and specialised technique. Mr. G. B. Crump said that he had interviewed many people for his company and had never met anybody who wanted to have anything to do with analytical chemistry at all.It was as if the whole pursuit had been concealed from them at college. Dr. Bark replied that few students at colleges have come across analytical chemistry, they only encounter analysis as there are far too few teachers of analytical chemistry. It was very unfortunate that currently there are only three Chairs in Analytical Chemistry in the UK; this probably reflects the feeling about analytical chemistry. This attitude is not confined to education. Industry had often behaved as if the man who was no good at anything else might just as well go to be an analyst. Very often it is the analytical chemist who holds the process together, and if there is not good analytical chemistry in technologically growing countries then the technological development will falter and cease. One needs to know “how much,” whether this is yield or pollution, and without such knowledge nobody will make progress. A. C. BUSHNELL

ISSN:0306-1396    

DOI:10.1039/AD9771400073

出版商:RSC    

年代:1977

数据来源: RSC

摘要:

April, 1977 ' ISOTACHOPHORESIS AND ISOELECTRIC FOCUSING 75 lsotachophoresis and lsoelectric Focusing The following are summaries of five of the poster presentations made at a Meeting of the Analytical Division held on November loth, 1976, at the Scientific Societies Lecture Theatre, 23 Savile Row, London. Detection of Soya Protein by lsoelectric Focusing J. W. Llewellyn Laboratory of the Government Chemist, Cornwall House, Stamford Street, London, SE 1 9NQ Soya protein has been detected in sausages and other uncooked meat products by the tech- nique of isoelectric focusing.lS2 The lyophilised and defatted meat products were heated in76 ISOTACHOPHORESIS AND ISOELECTRIC FOCUSING Proc.Analyt. Div. Chem. SOC. aqueous suspension at 100 "C for 15 min in order to render the meat insoluble, thereby enabling the selective extraction of the soya protein with 6 M urea solution containing 2% 2-mercapto- ethanol.After centrifuging the extract at 34 000 g for 30 min at 20 "C, 20-pl aliquots of the supernatant (containing approximately 800 pg of protein) were applied on filter-paper strips to the anode side of a 1.5 mm thick, 4.5% polyacrylamide gel (3% cross-linked, ampho- line concentration l.8y0), pH 3.5-10, which contained 6~ urea. The pH gradient was established by direct measurement on the gel surface with an antimony microelectrode.Focusing was performed by use of an LKB 2117 Multiphor at 5 "C with a constant power of 20 W for 3 h between 1% aqueous orthophosphoric acid as anode buffer and 1% aqueous diaminoethane as cathode buffer. The gel was stained3 by immersion in a 0.2% solution of bromophenol blue in ethanol - acetic acid - water (5 + 1 + 4) for 1 h and de-stained over- night in ethanol - acetic acid - water (6 + 1 + 13).The proteins appeared as opaque dark- green bands on a clear pale-yellow background and were scanned on a Joyce-Loebl Chromo- scan 201 scanning microdensitometer.Integration of the peak areas corresponding to the band patterns thus obtained, and comparison with the pattern from a soya protein isolate standard that had received identical treatment with the sample mixtures, enabled quan- titation of the soya protein. The technique was used to examine pork sausage meats, prepared in the laboratory, which contained known masses of added soya protein isolate.A 5% addition of isolate could be determined with a relative error of &20y0 ( i e . , as 5 & 1%) but at lower levels results were much less accurate. A 1% addition of isolate could just be detected but not quantified. The error at the lower levels of addition arose from the extraction of a small, but variable, amount of meat, which remained soluble after the initial heating stage, and also from variation in the intensity of staining.The method has been used to determine the soya-protein content of commercially available frozen beefburgers. It was unsuccessful with canned and baked products that had under- gone strong heating during production, with consequent denaturation of the protein, which was thus rendered insoluble in the extraction medium.The patterns of highly resolved bands afforded by proteins and protein sub-units are highly characteristic of the species examined. The patterns of egg, milk, field-bean and soya proteins are all easily identified and as a qualitative technique the method has considerable diagnostic potential. Identification is less simple however, when mixtures of two or more components are examined, unless selective extraction is possible, as the resulting band pattern is much more complex.The author thanks the Government Chemist for permission to present the posters and publish this work. The posters were presented by Mr. J. C. Hammond in the absence of Dr. Llewellyn. References 1. Flaherty, B., Chemy Ind., 1975, 495. 2. Llewellyn, J. W.,,and Flaherty, B., J.Fd Technol., 1976, 11, 555. 3. Awdeh, 2. L., SCZ. Tools, 1969, 16, 42. Analysis by lsoelectric Focusing of Phosphoglucoseisomerases in Schistosoma Species and Their Snail Hosts G. C. Ross Zoology Department, British Museum (Natural History), Cromwell Road, London, S W7 5BD Of the great tropical parasitic diseases, schistosomiasis still proves to be less amenable to control than many others owing, in part, to insufficient understanding of the biology of both the causative organisms and their snail hosts.To provide objective criteria for determining precise relationships between and within the species concerned, a number of experimental studies are being carried out, among which analysis of their isoenzyme systems by isoelectric focusing (IEF) is proving particularly valuable.Using starch-gel electrophoresis, only one orApril, 1977 ISOTACHOPHORESIS AND ISOELECTRIC FOCUSING 77 two often ill-defined isoenzymes of acid phosphatases and malate dehydrogenases (MDHs) are separated; IEF reveals fifteen or more. These two systems, however, have limitations; acid phosphatases do not always show differences between species while MDHs exhibit a more marked level of inter-population variation.This paper reports an assessment of phospho- glucose isomerase (PGI) isoenzymes in relation to the taxonomy of the schistosome worms and some snail hosts. Experimental Tissue extracts are prepared by maceration of perfused, washed worms in 10 p1 of water followed by standard freeze - thaw techniques. Supernatants are stored for up to 2 months a t -20 "C.The general technique recommended by LKB is modified by increasing the ampholine concentration to 1.3% and by bisecting the gel to allow concurrent pH gradient measurement and enzyme development. Apparatus and Materials Gel base plate A 260 x 150 x 1.5 mm glass sheet is scored across the plate 5 cm from one end. Ampholine mixture of pH 3.5-10, 2 parts of pH 4-6, 3.4 parts of pH 5-7 and 4 parts of pH 9-11.solution is stored at 4 "C. An ampholine mixture for an effective pH range of 4-9.5 consists of 32 parts of ampholine This stock Gel mixture For four plates, 30 g of sucrose are dissolved in 144 cm3 of water, then 40 cm3 each of 29.1% acrylamide and 0.9% NN-methylenebisacrylamide and 16.5 cm3 of ampholine mixture are added.Air is removed by a 700-mm vacuum and 1.6 cm3 of 5 mg-yo riboflavin are added prior to mould filling and photopolymerisation. Gels are stacked in sealed containers in a refrigerator with their upper surfaces protected by polythene sheets. Development mixture for PGI Solution A is prepared from 50 cm3 of 0.2 M tris - hydrochloric acid (pH S.O), 4 cm3 of 10% magnesium chloride solution, 50 mg of fructose 6-phosphate, 25 mg of triphosphopyridine nucleotide and 25 mg of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide.Solution A is heated to 50 "C before mixing with solution B. Solution B consists of 100 cm3 of 0.2 M tris - hydrochloric acid (pH 8.0) and 1.5 g of ion agar, and is brought to the boil and cooled to 55 "C. Solutions A and B are mixed and 25 units of glucose 6-phosphate dehydrogen- ase and 10 mg of phenazine methosulphate are added before the mixture is poured over the polyacrylamide gel, which is then covered in order to exclude light.p H measurement every 5 mm from the anodal edge of the gel plate in the range 20-110 mm. allowed on each reading. Readings are taken with the Pye Ingold 8-mm combined-membrane reference electrode A 3-min delay is Other apparatus A chiller thermocirculator to maintain antifreeze at 1 "C, a Vitatron recording densitometer for scanning separations with a 636-nm filter and a second cooling plate for pH measurement are used.Analysis programme The following programme is used, where T is the time when electrofocusing is begun. T - 30 min T - 15 min 1.Equilibrate gel plate to room temperature ; remove polythene sheet ; activate chiller thermocirculator ; select samples. 2. Apply samples to gel in rectangular-shaped drops. 3. Position soaked and blotted electrofocusing strips.78 ISOTACHOPHORESIS AND ISOELECTRIC FOCUSING Proc. AnaZyt. Div. Chem. SOC. T - 5 min T T to T + 40 rnin T to T + 90 min T + 110 min T + 120 min T + 120-180 rnin T + 130 min T + 170 min T + 2 4 h T + 7 2 h T + 5 d 4.5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21, 22. Apply gel plate to multiphor. Commence electrofocusing at 50 mA. Progressively raise potential to maintain 50 mA. Standardise pH electrode to pH 7. Prepare enzyme development solutions to preheating stages. Bring to stated temperature. Disconnect power supply ; remove gel plate from multiphor.Cut electrofocusing strips and gel above score-line and break base plate. Place small gel plate on second cooling plate and measure pH gradient. Remove focusing strips with underlying gel from larger plate and place plate in mould for isoenzyme detection. Complete preparation of isoenzyme development mixture and pour over gel. Fix optimally developed enzyme pattern by pouring 4% glycer- ine in 5% acetic acid over the gel.Replace fixative several times during 24 h to elute excess of photosensitive reagents. Cut gel plate from mould and measure band distances from anodal edge of plate, quantifying 1 +, 2+, etc. Transfer measurements to pH gradient graph and extrapolate p l value from each fraction. Scan plate on recording densitometer and correlate peaks with PI values from gradient graph, calculating relative percentages from integration counts.Place gel plate on warm surface to desiccate. Remove agar from margin around combined agar - polyacryl- amide gel layer and cover plate to 3 4 mm with 7% gelatin in 3% glycerol at 45 "C. Label marginal gelatin and store in racked boxes. Allow to harden at room temperature.Continuous analysis of several plates is obtained by repeating operations 1-6 concurrently wit1 7-11. Results Typical PGI isoenzyme patterns are shown in Fig. 1. Standard deviations of p l values of 0.016-0.035 and 0.013-0.029, with averages of 0.027 and 0.021, respectively, were obtained from two plates, the first containing 14 aliquots of a single extract of S.mattheei worms, each producing 19 fractions, and the other of 10 portions of S. margrebowiei with 22 fractions in each. The lowest p l of a-haemoglobin isolated in 50 separate experiments was 7.00 and the highest was 7.43, with a median value of 7.30 and a mean of 7.254, giving a standard deviation of 0.116. Species and sex discrimination are usually obtainable by qualitative examination only of both isoenzyme pattern and its scan profile.Females appeared to be deficient in activity in the pH 5-6 region. In a comparison of mated and unmated male worms of S. haematobium, taking four regions of pH 5.22-5.50, 5.56-5.79, 5.80-7.50 and 7.58-8.22, percentage activities in mated worms were 9.7, 17.1, 60.0 and 13.2, while the unmated males showed percentage activities of 12.6, 12.0, 65.2 and 10.2.Cercariae of S. Zeiperi passaged through mouse produced lower activity curves in the pH 4-6 region than those passaged through hamster. Comparing fractions at p l 5.41 and 6.95, the activities were 3.4 and 10.5y0 in mouse and 3.9 and 6.9% in hamster. Differences between strains of the same species were ascertained by gross analysis involving the total numbers of fractions, their p l values, distributions and percentage activities.For example, analysis of S. haematobiurn from Kenya, Ghana and Egypt and S. intercalatum from Zaire and Cameroon satisfied criteria identifying both species and strains. Vertebrate host influence was examined.April, 1977 ISOTACHOPHORESIS AND ISOELECTRIC FOCUSING 79 Fig. 1. PGI isoenzyme patterns from Schistosome worm extracts and Bulinid snail “blood” samples.1,11, Schistosoma leiperi from S . Africa, mated males passaged through mouse and hamster; 2,3, S. haematob- ium from Kenya, mated and unmated males; 4,5, S. intercalatum from Zaire, mated male and female, passaged through mouse; 6.7, as 4 and 5, passaged through Hamster; 8, S. intercalatum from Zaire, pattern from a single mated male; 9,10, S . bovis from Morocco, mated male and female; 12,13,B.ulinustvuncatztsfrom Israel and Lybia; 14, B.tvopicus from Rhodesia; 15,16, B. globosus from two localities in Ghana; 17, B. wrightii from South Arabia; 18, B. umbilicatus from Sudan. For snail hosts, blood patterns were much simpler than those of schistosomes. In 13 BuZinus spp.samples from one to three main fractions were shown at p l values from 4.9 to 5.4, whereas Biomphalaria sudanica, a host for S. mansoni only, showed six major bands from p l 5.4 to 5.9. This study was partially supported by a grant from The Edna McConnell Clark Foundation. A detailed study is continuing. pH Measurements in lsoelectric Focusing Gels Using an Antimony Electrode J. A.Beeley and J. G. Beeley Department of Oral Biology, University of Glasgow Dental School, 378 Sauchiehall Street, Glasgow, G2 3 JZ Department of Biochemistry, University of Glasgow, Glasgow, G12 SQQ Isoelectric focusing in polyacrylamide gels is now an established technique of high resolving power for the separation of proteins on an analytical scale. In this technique, proteins become focused as sharp bands at positions in a pH gradient where they carry no net charge.Accordingly, determination of the pH at which a protein focuses is a measure of its isoelectric point (pl). In pure protein preparations, p l measurements are of value in the study of charge heterogeneity. Even in impure preparations, p l measurements can be made provided that the specific protein of interest can be identified by its enzymic or immunological pro- perties.80 ISOTACHOPHORESIS AND ISOELECTRIC FOCUSING Proc.Analyt. Div. Chem. SOC. After several years of use, the best method of pH measurement on isoelectric focusing gels still appears to be use of an antimony micro-electrode.lS2 The technique is simple, rapid ((10 s per measurement) and the pH measurement is made at sharply defined points (approxi- mately 0.2 mm2 area) on the gel. Other methods of pH measurement have been used but most of them have major disadvantages. The most widely used of these methods has in- volved elution of gel samples with distilled water followed by determination of the pH of the eluate. This method can give erroneous results because of dilution of the ampholytes on elution from the gel and interference by atmospheric carbon dioxide1; it is also tedious, time consuming and, particularly with cylindrical gels, involves destruction of the gel.Marker pH indicators3 lack the precision needed for accurate p1 measurements. The use of a flat membrane micro-combination glass electrode has been de~cribed.~ However, this electrode has a diameter of 4 mm and, even when used on large gels, there is an appreciable pH change across the area of measurement.The antimony micro-electrode system designed by Kleinberg5 has been used extensively for pH measurements on isoelectric focusing gels and is shown in Fig. 1. It consists of an antimony micro-electrode, diameter less than 1 mm, and a remote liquid-junction reference micro-electrode.The system is manufactured by Probion (Fife) and is used in conjunction with a Radiometer 26 expanded-scale (Radiometer A/S, Copenhagen) or similar pH meter. Reference system Antimony electrode Calomel re element Magnified view of antimony tip Saturated (diameter <1 mm) sol u t i on Si I icone-ru bber tubing Porous ceramic liquid junction Fig. 1. Antimony electrode system.The electrode system is calibrated by means of a series of standard buffers and a calibration graph is constructed of the millivolt readings measured with the antimony electrode against The antimony tip can be positioned accurately on the surface of the gel at the point of interest, and the reference element positioned anywhere on the gel surface. With most gels, it is convenient to position the electrodes side by side.By placing the gel on a glass plate over a sheet of graph paper, accurate pH measurements can be made as little as 1 mm apart. When the protein bands can be seen, millivolt readings can be taken directly by applying the electrode to the band of interest. With most samples, however, protein bands can be located only after staining.In such instances, the gel is serrated at l-cm intervals with a scalpel blade after pH determination but prior to staining. The p1s of the protein bands revealed can be interpolated on a graph of millivolt readings against position on the gel and, PH.April, 1977 ISOTACHOPHORESIS AND ISOELECTRIC FOCUSING 81 by means of the serations, a correction factor to allow for shrinkage or swelling on staining can be applied if necessary.Only a few seconds are needed for stabilisation before millivolt readings are taken, the time necessary being slightly greater at the cathode than the anode end of the gel. The millivolt readings are converted into pH values by means of the cali- bration graph or use of a desk computer.lS2 The p l values obtained with this electrode agreed well with those obtained by other tech- niques.Replicate determinations fell within a range of less than 0.25 pH unit in gradients from 3 to 10. The speed with which measurements can be made minimises the loss of band resolution as a result of diffusi0n.l It is important that the millivolt measurements are made as near as possible to the running temperature of the gel, and that the values on the calibration graph are also determined at the same temperature.The pH changes that occur in ampholines on change of temperature are large, particularly at alkaline pHs (Table I).617 TABLE I EFFECT OF CHANGE OF TEMPERATURE ON pH OF AMPHOLINE' Ampholine pH (1% solution %/ pH range a t 25 "C) pH "C-1 3-6 4.4 - 0.004 5-8 6.5 - 0.016 7-10 8.75 - 0.023 In general, the antimony electrode has not been widely used for pH measurements because it was considered to be unstable and to require frequent reconditioning. For the antimony micro-electrode described here, use of which has been confined to pH measurements in iso- electric focusing gels, the opposite has been shown to be true.Our original electrode has been in regular use for over 5 years and still gives a calibration graph that is superimposable on the original; during this time it has neither been reconditioned nor received any special treatment other than washing with distilled water after use and careful drying.The repro- ducibility of the electrode as determined by 10 repeated measurements on Ampholine fractions was shown to be less than *O.l pH unit (Table II)*; in a 10-cm gel of pH 3-10, the pH change across a 1 mm diameter electrode would be approximately 0.07 pH unit, and hence the repro- ducibility of the electrode is compatable with the limits of the system under investigation. TABLE I1 REPRODUCIBILITY OF pH MEASUREMENTS WITH AN ANTIMONY ELECTRODE Each value shows the deviation observed on making 10 repeated measurements on the same ampholine fraction, washing the electrode between each measurement.* Measurements made on the same solution with a glass electrode are shown for comparison. Ampholine pH r I Antimony electrode Glass electrode 4.16 & 0.054 and i- 0.052 7.32 f 0.091 and f 0.072 9.33 f 0.095 and f 0.089 4.16 f 0.008 7.40 f 0.011 9.31 + 0.004 A micro-electrode system for isoelectric focusing gels based on principles similar to those outlined above has recently become commercially available (Bio-Rad Gel Pro-pHiler, Bio-Rad, Richmond, Calif.) but it can be used only on cylindrical gels and measurements can only be made 5 mm apart. Desaga (Heidelberg) manufacture a glass micro-electrode system for use in conjunction with isoelectric focusing; this equipment is more costly, more fragile and has a larger diameter (1.5 mm) than the antimony electrode, but can be supplied with an adjustable holder for accurate vertical and horizontal positioning of the electrode.An iridium-wire electrodes has also been claimed to be suitable for pH measurements on isoelectric focusing gels.82 ISOTACHOPHORESIS AND ISOELECTRIC FOCUSING Proc. Analyt.Div. Chem. Soc. As carrier ampholytes become more costly, the use of smaller gels (e.g., on microscope slideslo) will become more widely accepted. For pH measurements on such miniature gels, an electrode of the dimensions of the antimony system described here is the only one likely to be of use. References 1. Beeley, J. A., Stevenson, S. M., and Beeley, J. G., Biochim. Biophys.A d a , 1972, 285, 293. 2. Beeley, J. A., Stevenson, S. M., and Beeley, J. G., in Arbuthnott, J. P., and Beeley, J. A., Editors, “Isoelectric Focusing,” Butterworths, London, 1975, pp. 147-151. 3. Conway-Jacobs. A., and Lewin, L. M., Analyt. Biochem., 1971, 43, 394. 4. Wf!liamson, A. R., in Weir, D. M., Editor, “Handbook of Experimental Immunology,” Volume 1, 5. Kleinberg, I., Brit.Dent. J., 1958, 104, 197. 6. Davies, H., Protides Biol. Fluids, 1969, 190, 389. 7. Fawcett, J. S., personal communication. 8. Davies, H., personal communication. 9. Righetti, P., unpublished observations. 10. Awdeh, Z., personal communication. Immunochemistry,” Second Edition, Blackwells, Oxford, 1973, pp. 8.1-8.23. lsotachophoresis H. D. Fairley LKB Instruments Ltd., 232 Addington Road, Selsdon, South Croydorz, Surrey, CR2 8YD Isotachophoresis is a method of separating ion species and, as the name implies, it is charac- terised by giving all ions under observation the same migration velocity.By using this principle, ions are separated as a result of differences in their net mobilities. In comparison, other electrophoretic techniques, for example those using cellulose acetate, polyacrylamide, etc., separate ion species as a result of differences in their net charges and the ions under observation migrate at velocities that are dependent on the charges on individual ions.In practice, this equal velocity principle results in reduced diffusion at zone boundaries and the resulting high resolution and fast analysis times are important features of the tech- nique.Although the original concept of isotachophoresis was developed by Kohlrausch in 1897, it has only been within the past few years that further development work has produced practical working systems, based on capillary-tube isotachophoresis. These systems, which include built-in detectors measuring ultraviolet, conductivity and thermal differences between separated zones, can provide both quantitative and qualitative analyses of ion mixtures.To date, about 150 scientific publications have reported successful work involving the use of isotachophoresis. Some of the more important papers are listed below.l-12 The poster display at this meeting concentrated on three areas of application, which were as follows. A . Purification control of the synthetic peptide Somatostatin.The cyclic tetradecapeptide was synthesised by the solid-phase technique and analytical isotachophoresis was used to give qualitative and quantitative analyses of the peptide during purification procedures, which included gel-filtration and partition chromatography. The results obtained by using analytical isotachophoresis were compared with those from thin-layer chromatography and it was found that analytical isotachophoresis allowed the qualitative and quantitative analyses of the level of somatostatin at various stages in the purification process.In general, the sample load was 20 pg and the analysis time was 10-15 min. The separation of nucleotides by isotachophoresis. The separation of the 5’-substituted mono-, di- and triphosphates of adenosine, cytidine, guanosine and uridine was investigated.Isotachophoresis separates ions because of differences in net mobility, which is a function of ion mobility and the degree of dissociation. The separation is therefore pH dependent and can be optimised by choosing an appropriate pH for the leading electrolyte. In order to establish optimum conditions for the separation of a range of nucleotides a series of experiments was carried out to establish the net mobilities of these ions over a wide pH range.These experi- ments confirmed the theoretical calculation that optimum resolution was obtained in the pH range 3.54.0 and that an electrolyte system using C1- as the leading ion and caproic acid as the terminating ion covered the necessary range of mobilities.B.April, 197'7 ISOTACHOPHORESIS AND ISOELECTRIC FOCUSING 83 C. Amino-acid analysis by analytical isotachophoresis. A series of experiments was carried out to study the resolution in different electrolyte systems for the generally occurring amino-acids. As the difference in ionic mobility between amino-acids is very small, it is likely that a separation based on ionic mobility would not be successful.Therefore, separa- tions based on the degree of dissociation of the amino-acids were investigated. As the pK values of the amino group for amino-acids range from 9.1 (serine) to 9.8 (glycine), investi- gations were carried out in the pH interval 8.6-9.7, using C1- as the leading ion and p-alanine as the terminating ion, These studies confirmed that although isotachophoresis is a suitable analytical method for the analysis of hydrolysates of small peptides and other amino-acid mixtures containing a limited number of amino-acids, because of limitations in separation capacity this technique can hardly compete with standard methods now in use for the analysis of amino-acids in protein hydrolysates and physiological fluids.References 1. Sjodin, R., Kopwillem, A., and Karlsson, J., Protides Biol. Fluids, 1975, 22, 733. 2. Sjodin, B., Kopwillem, A., and Karlsson, J., Scand. J . Clin. Lab., 1975, 35, 699. 3. Dunn, J . P. D., and Kemp, R. B., Protides Biol. Fluids, 1975, 22, 727. 4. Beckers, J. L., and Everaerts, F. M., J . Chromat., 1973, 76, 227. 5. Beckers, J . L., and Everaerts, F.M., J . Chromat., 1972, 71, 380. 6. Kopwillem, A., and Lundin, R., LKB Application Note No. 159. 7. Kopwillem, A., and Righetti, P., LKB Application Note No. 110. 8. Moberg, U., LKB Application Note No. 186. 9. Kopwillem, A., Merriman, W. G., Cuddeback, R. M., Smolka, A. J . K., and Bier, M., J . Chromat., 1976, 10. Moberg, U., LKB Application Note No. 187. 11.Kjellin, K. G., Sci. Tools, 1975, 22, 3. 12. Beckers, J. L., and Everaerts, F. M., J . Chromat., 1972, 69, 165. 118, 35. lsotachophoretic Analysis of Muscle Extracts D. C. Gower and R. C. Woledge Department of Physiology, University College London, Gower Street, London, WClE 6BT Isotachophoresis, an electrophoretic technique, separates ions according to their mobilities in an electric field.The sample ions are introduced between a faster moving leading electro- lyte and a slower moving terminating electrolyte. A constant current is applied to the system and separation of the ions into zones takes place; these zones remain adjacent to each other in order of their net mobilities. Zones of ultraviolet-absorbing and non-ultraviolet-absorbing materials can be located by comparison of analytical records from muscle extracts with and without the addition of standard solutions.Separation of anions took place in a 43-cm long PTFE capillary tube, 0.5 mm i.d., which was thermo- statically controlled at 15 "C. The leading electrolyte was 5 mM hydrochloric acid, with 18 mM p-alanine as counter ion, in 0.5% methyl cellulose at pH 3.92. The terminating electrolyte was 5 mM hexanoic acid.All measurements of ultraviolet absorbance were made at a wave- length of 254 nm, the electrophoretic current at detection being 50 pA and the run time about 20 min. The determination of non-ultraviolet-absorbing materials was found to be possible by measuring the width of a zone between ultraviolet-absorbing materials. Provided that such a zone contains only one component, the length of the zone should be proportional to the amount of material.This was clearly demonstrated by the construction of standard graphs for phosphocreatine (range 1-100 nmol) and inorganic phosphate (range 2-20 nmol). In the instance of ultraviolet-absorbing materials, the area under the peak on the records, after transforming from a transmission scale to an absorbance scale, is linearly related to the amount of material.By using this method of calibration standard graphs of adenosine nucleo- Cyclic AMP has been identified by enzymatic conversion to AMP. The following results were obtained by using an LKB 2127 Tachophor.84 ISOTACHOPHORESIS AND ISOELECTRIC FOCUSING Proc. Analyt. Div. Chem. SOC. tides covering a range of 0.01-50 nmol were constructed.Linearity was satisfactory through- out the range investigated. Satisfactory resolution of compounds likely to occur in muscle extracts was indicated by the analysis of a mixture containing ATP, ADP, c-AMP, AMP, NADH, NAD, IMP, Pi and PCr. No interference could be detected between adjacent zones when a fixed amount of c-AMP (43.7 pmol) was separated from various amounts of AMP (0-2 338 pmol).Muscle extracts were prepared by immersing flattened, frozen, frog sartorius muscles (wet mass about 66 mg) for 4 d in 3 ml of 1.25 mM EDTA (pH 7.6) in solution in 50% methanol at -30 "C. Extracts were subsequently freeze dried and re-dissolved in 3 ml of distilled water. Suitable analysis records were produced by using 10 p1 of these muscle extracts (equivalent to 0.15 mg of wet muscle or 0.02 mg of dry muscle).Analyses of a single extract were repeated 10 times and satisfactory repeatabilities for several muscle components were found. Estimates of the amounts of ATP and PCr in muscle extracts obtained by the Tachophor and AutoAnalyzer methods were in good agreement. However, it was noted that inorganic phosphate measurements obtained by use of the Tachophor method were higher than expected.By analysing a sample before and after Pi precipitation it was evident that the Pi zone con- tained one or more other materials from the muscle besides Pi. Also, the long non-ultraviolet- absorbing zone of EDTA (resulting from the extraction medium) of muscle extracts may contain certain muscle components, such as fructose-1 , 6-diphosphate, pyruvate, phospho- enolpyruvate and 3-phosphoglyceric acid.It must also be remembered that zones resulting from impurities in the leading and ter- minating electrolytes do combine with certain sample zones and hence it is necessary to measure such blank zones on each batch of electrolytes used and subtract their integrated areas from the appropriate sample zones.As the Tachophor possesses a high resolving power of ultraviolet-absorbing materials, its use in the determinations of purity of certain nucleotides, especially before and after puri- ficat ion procedures, was illustrated. It was concluded that isotachophoresis can provide useful analyses of muscle extracts. Its advantages are: that it resolves several metabolites in one run; that both ultraviolet- absorbing and non-ultraviolet-absorbing materials can be measured simultaneously ; that it is sensitive to picomole amounts; that both large and small amounts of different compounds can be measured simultaneously; that it is relatively quick to run (about 3 runs per hour); and that the leading and terminating electrolytes can be changed very easily to provide a new set of conditions.However, certain limitations are evident: very complex tissue extracts may be hard to resolve; only ions can be measured and only anions or cations in one run; a limited range of ultraviolet wavelengths only can be used; and the solution to be analysed should be relatively concentrated, at least 10 p ~ . A more detailed account of this work will appear.1 Reference 1.Gower, D. C., and Woledge, R. C., Sci. Tools, 1977, 24 (1). The following is a summary of one of the full papers presented at the meeting.April, 1977 ISOTACHOPHORESIS AND ISOELECTRIC FOCUSING Analytical lsotachophoresis 85 F. M. Everaerts Laboratorium UOOY Instrztmentale Analyse, Technische Hogeschool Eindhoven, Postbus 51 3, Eindhoven, The Netherlands Electrophoretic separation techniques nowadays seem to be linked mainly with protein chemistry and chromatography, as a result of the work of Hardy, Michaelis, Svedberg, Tiselius, Martin, Svensson, Ornstein and Davis, and many more names could be given.As capillary systems for electrophoresis have been applied and detection systems with high response and sensitivity are available, electrophoresis now has more general applicability as an analytical separation technique.Of the four basic principles, zone electrophoresis, iso- tachophoresis, moving-boundary electrophoresis and isoelectric focusing, it is mainly iso- tachophoresis that is currently being studied in our laboratory.1 Principle of Isotachophoresis In isotachophoresis, it must be decided whether a separation of anionic or cationic species will be performed, and in this paper only the separation of the anionic species B and C will be considered.Three different electrolytes can be recognised at three different locations in the isotachophoretic equipment : 1. the leading electrolyte, which, in anionic separations, fills the separation compartment and the anode compartment; 2.the terminating electrolyte, which fills the cathode compartment; and 3. the sample, which is introduced between the leading and terminating electrolytes. The anionic components of these electrolytes have to satisfy the important requirement that the leading ionic species A must have the highest effective mobility (peff), while the terminating ionic species T must have the lowest effective mobility.The sample contains constituents B and C with intermediate mobilities : The first stage of the electrophoretic process will proceed along the lines of the moving- boundary principle (Fig. 1, 2 4 ) . As the amount of sample is limited, there will be a time after which the sample is separated. In this so-called steady state (Fig. 1, 5), there will be two zones, each containing a sample ionic species sandwiched between the leading and ter- minating electrolytes. Hence isotachophoresis can be compared with chromatographic displacement. Once the steady state has been reached, there will be present, in the separation compartment, four different zones, within a frame of three zone boundaries, which move with equal velocity.In fact, it was this phenomenon that was the basis for naming this electro- phoretic principle isotachophoresis: C(TOS = equal; Taxes = velocity; C~OPEEOTML = to be moved. That the velocities must be equal can be readily understood by assuming the opposite situation. When, for example, the leading zone moves faster than the following zone, there would be an anionic “vacuum” between the two zones.This “vacuum” would contain only cations, which is against the principle of electroneutrality. Therefore, once the steady state has been reached, the velocities (v) must be equal. In electrophoretic terms, this has been called the isotachophoretic condition1 : .. * * (2) v* = v, = v, = v, . . .. .. According to the regulating function concept, the electrophoretic characteristics of the steady state again will be strictly regulated, as is shown in Fig.2. These characteristics of the steady state can be calculated. For convenience, we assume the presence of only strong, singly charged ionic species, with constant properties, i.e., peff = pm. Considering the86 ISOTACHOPHORESIS AND ISOELECTRIC FOCUSING Proc. AnnaZyt. Div. Chem.SOC. Fig. 1. The isotachophoretic separation process (anionic species) as a:function of time. Fig. 2. Characteristics of the isotachophoretic “steady state.” V = potential; E = electric field strength; T = temperature.April, 1977 ISOTACHOPHORESIS AND ISOELECTRIC FOCUSING steady state, the is0 t achophoretic condition requires 87 As the current density is assumed to be constant, the product of the electric field strength and specific conductance will also be constant : j = EK = constant .. . . . . - * (4) The specific conductance is the sum of all ionic contributions, so we can write KA = F(cApA + cbpb) - * . . . . . . where b is the counter-ionic species. Using the electroneutrality principle for zone A . . . . ’ - (6) C A = C b . . .. .. and equation (5) becomes In a similar way, we find for the other zones: or The isotachophoretic condition can now be combined with equations (7) and (9) to give .Equation (10) is equivalent to the “Kohlrausch regulation function”2 for the case of iso- tachophoresis.Firstly, this equation contains, for a fixed leading electrolyte, two quantities that may vary, although not independently.As, for a given ionic species, the ionic mobility is a characteristic pro- perty, equation (10) states that the concentration of that ionic species, once the steady state has been reached, is invariably related to the leading electrolyte and therefore will be con- stant for a given leading electrolyte. Hence the concentration can be calculated if all ionic mobilities involved and the concentration of the leading ionic species are known.Further, equation (10) means that the length of a zone is a measure of the absolute amount of ionic species. If, for example, the absolute amount of constituent B in the sample is doubled, the zone length occupied by the constituent B in the steady state will also be doubled. Therefore, we must conclude: the length of a zone in isotachophoresis contains information concerning amount.From the isotachophoretic condition [equations ( 2 ) and (3)], we can derive another important feature of isotachophoresis. Because of the fact that in the steady state all velocities are equal and because of the discrete order of mobilities, the electric field strength increases stepwise from zone to zone, from the leading zone to the terminating zone: From this relationship, several important conclusions can be drawn.E A < E B < E, < E, .. .. .. .. (11) and Ei =.E E A .. .. .. .. . . (12) Pt The right-hand side of equation (12) contains a species-specific property and the relationship can therefore be used for identification purposes. Thus : qualitative infowzation in isotacho- phoresis i s obtained from the electric jield strength.88 ISOTACHOPHORESIS AND ISOELECTRIC FOCUSING Proc.Analyt. Div. Chem. SOC. As the heat produced in a zone and hence the temperature of a zone are directly related to the electric field strength, measurement of the zone temperature can also be used for qualifi- ~ a t i o n . ~ The use of the electric conductance for identification purposes is obvious.In calculating the different electrophoretic characteristics, we made some simplifications. The concept, of course, can be extended to more complex situations, in which allowance can be made for multiple charges, dissociation, temperature effects, etc.1 In fact, there are several computer programs a~ailable*-~ that can be used for the calculation of isotachophoretic steady-state configurations.Moreover, it should be emphasised that the constant current density mode is not necessary for isotachophoresis, although in practice it is the most con- venient mode. Obviously, the transition boundary between two consecutive zones must be very small, owing to the so-called “self-correcting” effect of the zone boundaries. Suppose that species B (Fig.1, 5 ) is located €or some reason in the zone of species C. There it will be confronted with an electric gradient that is relatively high compared with that in its own zone. Owing to the higher gradient, the “lost” species will move back from the zone of species C to the zone where it belongs. This effect, of course, means that dispersion, for example by diffusion, in isotachophoresis is optimally levelled and that the zone boundaries are extremely sharp and remain so irrespective of the time of analysis.This self-correction phenomenon is, of course, closely related to the process of separation. As has already been mentioned, the separation process in isotachophoresis proceeds according to the moving-boundary principle. The process as a function of time has been illustrated in Fig.1. The steady state in isotachophoresis is a strictly regulated state, as also holds for the separation process and, in practice, this means that all electrophoretic characteristics, as long as they exist, are constant with time. The time needed for a full separation (steady state) is determined by the current density, the leading electrolyte and the sample.I t must be emphasised that within the total system (Fig. 1, 1) there are three regions, which may have their own regulating functions : the cathode compartment (T), the sampling compartment (B + C) and the separation compartment (A). These functions are locally invariable and need not necessarily match with one another. This situation, of course, may give rise to discontinuities, which generally do not migrate.The various parameters again can be calculated, although the mathematical intricacy increases exponentially with the number of components involved. Instrumentation An extensive description of the equipment for isotachophoretic analyses is given in a recent book1 and therefore only a brief description is given here (Fig. 3).7 The equipment consists of two electrode compartments (2, 16), which are directly connected with the current-stabilising power supply (l), an injection block (4) and/or an injection valve (7) and a narrow-bore tube (8).To prevent a hydrodynamic flow between the two electrode compartments, a semi-permeable membrane (17) is mounted between the electrode compartment (16) and the central block (18), in which various canals are drilled.One of these canals is connected directly with the separation compartment (8) and the reservoir of the leading electrolyte (24). The separation compartment is a narrow-bore PTFE tube of i.d. 0.2 mm and 0.d. 0.4 mm. This internal diameter was found to be optimal because, among other reasons, the temperature difference between the various zones is small.Moreover, the convective disturbances are also small and the zone profile is influenced The sample can be introduced by means of a microlitre syringe into the injection block (4) or via a six-way valve (7). In the position such that 7d is connected with 7a (7e-7f and 7c-7b) a sample can be introduced, the narrow-bore tube can be rinsed and re-filled and the terminating reservoir can be rinsed and re-filled. In the position drawn in Fig.3, the valve is in its operational mode. Because in isotachophoretic analyses the sample zones are separated in consecutive zones according to their effective mobilities, all zones have their characteristic features (tem- perature, conductance, pH and potential gradient). Moreover, a zone may exhibit ultraviolet absorption, optical rotation or fluorescence or radioactive compounds may be present.A thermometric detector3 (a thermocouple made of copper - Constantan wires with a diameter of approximately 25pm and a micro-beat thermistor) was first developed as a detectionApril, 1977 ISOTACHOPHORESIS AND ISOELECTRIC FOCUSING 89 T Fig. 3. Schematic diagram of an instrumental set-up suitable for isotachophoretic analyses (from reference 7, by courtesy of Marcel Dekker, Inc.).system, mounted on the outside of the narrow-bore tube. The response of the thermo- metric detector is rather low, but its sensitivity is still comparable with that of high-resolution detectors (conductimetric, potential gradient and ultraviolet absorption detectors). More recently, a potential gradient detector and a conductivity detector (14) with micro-sensing electrodes (10 pm platinum - 10% iridium) in direct contact with the electrolytes have been developed.In most instances the conductivity probe is made of acrylic material. The electrodes are mounted axially, such that the electrolyte remains surrounded by an unin- terrupted cylindrical wall. A contact adhesive is used for the construction of the probe and the cell volume is a few nanolitres.In our equipment, an ultraviolet absorption detector is also mounted, the ultraviolet source being a microwave mercury electrodeless discharge lamp. The ultraviolet radiation is guided by a quartz rod of optical quality (11) into a slit with a diameter of 0.1 mm, passes through the narrow-bore tube and is guided again by another quartz rod towards an ultraviolet-sensitive photodiode.More information can be found in ref. 1.90 ISOTACHOPHORESIS AND ISOELECTRIC FOCUSING Proc. ArtaZyt. Div. Chem. SOC. PTFE-lined valves are fitted a t various positions in the equipment, for connection with the electrolyte reservoirs and the drain. For experiments with a counter flow of electrolyte, a special regulated pump has been constructed.1 The reservoir (21) can be filled with an electrolyte such as potassium chloride solution (0.1 N). Between this reservoir and the central bores of the electrophoretic equipment is mounted a pre-stressed contraceptive membrane (22).If gas is now produced in the electrolysis cell (21), its volume will; expand, displacing the thin membrane (22) between the two reservoirs.This results in a counter flow of electro- lyte inside the narrow-bore tube. The amount of gas produced is regulated by electronics (23) and the isotachophoretic moving zones can be stopped somewhere in the narrow-bore tube. There are several clearly distinguishable parts in the electrophoretic equipment (Fig. 3) : the reservoir for the terminating electrolyte (2) ; the place where the sample can be introduced (4, 7 ) ; the separation compartment (8); and the place where the detectors are mounted (12, 14).Other components are a PTFE-lined two-way valve (3), the drain (5), a tap with a silicone tip (6), the power supply for the ultraviolet lamp and the ultraviolet detector (9), the ultraviolet source (lo), the ultraviolet slit (12), the ultraviolet detector with a set of filters (13), the electronics for the conductimeter (15), two further PTFE-lined two-way valves (19, 20) and the connection with a potentiometric recorder (25).Example of an Isotachophoretic Separation The analysis was carried out in the operational system listed in Tables I (left-hand side) and I1 (right-hand side).Atropine (2.98 nmol) that had been poorly sterilised (30 min, 130 "C) was injected (left-hand side). In the left-hand isotachopherogram the degradation products tropane and methylamine are clearly shown. In order to show that An arbitrarily chosen isotachophoretic separation is shown in Fig. 4. The time of analysis was 12 min. 7 Is Fig. 4. Isotachophoretic separation of poorly sterilised atropine sulphate solution. 1 = K+; 2 = Na+; 3 = atropine+; 4 = r-aminocaproate+; 5 = C1-; 6 = Sod2-; 7 = MES-.R = increasing electricresistance; A = increasing UV absorption; t = increasingtime. From the step heights (linear traces of the conductivity detector) qualitative information can be obtained, while from the step lengths (linear traces of the conductivity detector) or distances between peaks (differential trace) of the conductivity detector quantitative information can be derived. The UV absorption detector gives additional specific information (linear trace) (from reference 7, by courtesy of Marcel Dekker, Inc.).April, 1977 ISOTACHOPHORESIS AND ISOELECTRIC FOCUSING TABLE I OPERATIONAL SYSTEM FOR ISOTACHOPHORETIC SEPA4RATION OF CATIONS AT pH 5.0 Solvent: water.j = 0.08 A cm-2. Purification: the additive is purified. Electrolyte 91 r 1 Leading Terminating Cation K+ E- Aminocaproat e Concentration 0.01 N ca. 0.01 N Counter ion CH,COO- CH,COO- PH Additive 5.0 4.0 0.05% hydroxyethylcellulose None TABLE I1 OPERATIONAL SYSTEM FOR ISOTACHOPHORETIC SEPARATION OF ANIONS AT pH 4.50 Solvent: water. j = 0.08 A cm-2. Purification: morpholinoethanesulphonic acid (MES) is recrystallised three times and the crystals are washed with acetone; e-aminocaproic acid is recrystallised; the additive is purified. Electrolyte Leading Terminating Anion c1- MES- Concentration 0.01 N ca. 0.01 N Counter ion HOOC-C,H,-CH,N+H Tris-H+ Additive 0.05% hydroxyethylcellulose None PH 4.50 ca. 7 tropanoic acid was aIso present, the right-hand isotachopherogram is shown. From a cali- bration graph it can be calculated that the amount of atropine is reduced to 60% owing to the poor sterilisation. From such isotachopherograms, mass balance can be made in order to study the degradation (in other instances kinetics) as a function of time. Isotachophoresis has been applied succesfully to the qualitative and quantitative analysis of amino-acids, carbohydrates, complexes, inorganic anions, metal ions, nucleotides, organic ions, peptides and proteins. Isotachophoretic equipment is now commercially available (LKB-Produckter AB, Bromma, Sweden). List of Symbols K cm2 R-1 equiv-l p cm2V-1s-l A R b C E V cm-l F C equiv-l R R T c equiv ~ r n - ~ 2 j Acm-2 t s v cm s-1 Specific electric conductance Mobility Ionic spcies (leading ion) Ionic species (sample ion) Ionic species (counter ion) Ionic species (sample ion) Electric field strength Faraday constant Electric resistance Ionic species (terminating ion) Concentration Ionic species Current density Time Linear velocity References 1. Everaerts, F. M.. Beckers, J. L., and Verheggen, Th. P. E. M., “Isotachophoresis,” Journal of Chroma- 2 . Kohlraush, F., Annln Phys., 1897, 62, 209. 3. Martin, A. J. P., and Everaerts, F. M., Proc. R. Soc. Ser. A , 1970, 316, 493. 4. Routs, R. J., Thesis, Eindhoven University of Technology, 1971. 5. Everaerts, F. M., Beckers, J. L., and Verheggen, Th. P. E. M., Ann. N.Y. Acad. Sci., 1973, 209, 419. 6. Jovin, T. M., Ann. N . Y . Acad. Sci., 1973, 209, 477. 7. Everaerts, F. M., Mikkers, F. E. P., and Verheggen, Th. P. E. M., in Perry, S., van Oss, C. J., and Grushka, E., Editors, “Separation and Purification Methods,” Marcel Dekker Inc., New York, 1977. 8. Verheggen, Th. P. E. M., Mikkers, F. E. P., and Everaerts, F. M., J . Chromat., 1977, 132, 205. tography Library, Volume 6, Elsevier, Amsterdam, 1976.

ISSN:0306-1396    

DOI:10.1039/AD9771400075

出版商:RSC    

年代:1977

数据来源: RSC

摘要:

92 EQUIPMENT NEWS Proc. Analyt. Div. Chem. SOC. Equipment News Ion-selective Electrodes Orion have developed two-ion selective elec- trodes for the rapid measurement of sodium, potassium and calcium from whole-blood samples. The Space-Stat 30 can give sodium and potassium measurements in less than 1 min. A sample of blood is injected into the instrument and concentrations of both ions are shown on a digital display.The Space-Stat 20 utilises the same principle and ionic calcium concentration is displayed in under 3 min. This is generally recognised as being a more clinically important factor than total calcium determination. Both instruments are ideal for processing large numbers of samples, virtually instantaneous results being available to the Diagnostician. MSE Scientific Instruments, Manor Royal, Crawley, Sussex, RHlO 2QQ.Radio Immunoassay Counter A new, compact, single channel system, based on Nuclear Enterprises Scaler-Timer ST6 and Scintillation Counting Assembly 6006, is now available for assaying iodine-125 and other gamma-emitting isotopes in small samples. Both low activity liquid and solid sources can be measured. Counting efficiency is of the order of 75% for iodine- 125 and background is approximately 45 c.p.m. with a standard crystal and 25 c.p.m.with a special crystal. Sample vials are con- tained in batches of 16 in disposable trays. Nuclear Enterprises Ltd, Bath Road, Been- ham, Reading, RG7 5PR. Sample Diluter The Vitatron Diluter will dilute samples from as small as 3 ,d to as large as 2.5 cm3 accurately and reproducibly, with a rapid cycle time.This makes i t useful for radioimmunoassay and other techniques requiring precise dilution of very small volumes. Features include Hamilton gas-tight syringes, optional foot-switch operation PTFE valves and a dilution accuracy of less than 1 yo. MSE Scientific Instruments, Manor Royal, Crawley, Sussex, RHlO 2QQ. Vacuum Flow Controller The SGE Model 8298 controller is designed to maintain a pre-set flow of air a t sub-atmospheric pressures despite variations in upstream or downstream pressures.The flow is determined by an easily interchanged flow element, available for a number of rates between 25 and 1000 cm3 min-l of air. The controller operates by maintaining a constant pressure drop across the element and will maintain the rate to within &2%, with changes of 0-0.2 atmospheres up- stream and/or 0.3-0.97 atmospheres downstream.Construction is of anodised aluminium with two mechanically coupled Buna-N diaphragms and &-in Swagelok couplings. The controller is intended for applications such as air pollution monitoring, where it is necessary to draw air through a detector or sampling tube a t a con- stant rate. Scientific Glass Engineering (UK) Ltd., 657 North Circular Road, London, NW2 7AY.Portable Dissolved Oxygen Meter The Hach portable dissolved oxygen meter utilises Clark-type polarographic electrodes. The sensor is immersed in the river, lake or out- fall to be tested, dissolved oxygen passes through a semi-permeable Teflon membrane, leaving dissolved organics and suspended solids behind, and the reading is displayed on a 4B-in analogue meter.The instrument uses six 1.25-V re- chargeable Ni - Cd batteries and has ranges of 0-10 and 0-20 mg 1-1 with the standard mem- brane and 0-5 and 0-10 mg 1-1 with the high- sensitivity membrane. Pressure compensation enables readings to be taken a t depths down to 230 f t and temperature compensation covers the range from -2 to 45 "C.Camlab, Nuffield Road, Cambridge, CB4 1TH. Clinical Osmometers The Advanced Instruments 3D2 freezing-point depression osmometer is designed for the clinical diagnosis of electrolyte imbalance caused by such conditions as renal failure, hypergly- caemia, uraemia, diabetic acidosis and drug poisoning. The instrument measures the freez- ing-point, and hence osmolarity, of a serum or urine sample automatically and stores the digital result a t the end of the test. A tape print-out sequentially records each test, while identifying and coding any errors.An option1 BCD output is available for direct link to a computer. MSE Scientific Instruments, Manor Royal, Crawley, Sussex, RHlO 2QQ. Kjeldahl Nitrogen Apparatus The Buchi 425 digestion apparatus incorporates four digestion tubes with a common fume extrac- tion device, which is connected to an extraction pump, thus obviating the need for a fume cup- board.The 425 has a stepless heat control providing a wide range of decomposition condi- tions. The digestion tubes double as distilla- tion vessels for use on the associated Buchi 320April, 1977 EQUIPMENT NEWS 93 nitrogen determination apparatus.The latter is designed for ease and speed of operation, with press-button controls on the front panel and automatic extraction of the distillation residue into a integral storage tank. Orme Scientific Ltd., Stakehill Industrial Estate, Manchester, M24 2RH. Liquid Chromatography Detector The Tracor, Model 960, fixed wavelength (254 nm) absorbance detector features very low noise (2.5 x 10-5 absorbance unit) for high- sensitivity operation.Its fast response, 0.5 s for 90% f.s.d., makes it extremely suitable for monitoring the high-speed separations now being achieved with microparticulate columns. High efficiency is achieved by the use of a low-volume (8 ,d) liquid cell and an integral standard is included to provide absorbance calibration.The 960 is available as either a self-contained module for use with existing instrumentation or as part of a complete system. Techmation Ltd., 58 Edgware Way, Middlesex, HA8 SJP. Spectro fluorimeter The Spex Fluorolog spectrofluorimeter is a digital research-grade instrument, incorporating double monochromators for excitation and emis- sion. Scattered light is so low that fluorescence measurements can be made on such intransigent media as turbid liquids and rough solids.The modular construction and very large sampling area make it suitable for a wide range of applica- tions. A photon-counting detection system is available that results in improved signal to noise ratio. In addition to standard emission and ratio emission measurements, transmittance, absorb- ance and partial fluorescence can be measured without changing the configuration of the Fluorolog.In the ratio emission mode, excita- tion spectra are corrected automatically by the reference detector. Emission and higher order corrections are possible with the computerised counterpart of the instrument, known as Fluorocomp.This incorporates a computer and necessary software. A phosphorimetry attachment is available, together with such other accessories as sample heater - cooler, variable temperature accessory and polarisation kit. Glen Creston, 16 Carlisle Road, London, Tu’W9 OHL. Toxic Gas Analysers Detection Instruments Ltd. have announced a new range of toxic gas analysers, including portable monitors and units for fixed installa- tions.The analysers utilise an electrochemical transducer, which can be made specific for carbon monoxide, sulphur dioxide, hydrogen sulphide, nitrogen dioxide and chlorine. An accuracy of &2y0 f.s.d. is claimed. The portable toxic monitors are powered by internal rechargeable batteries, but can also be operated on a.c. mains. They are marketed with a wide range of linear scales and fully adjustable audible and visual alarms.Each instrument weighs 8 lb and is fully portable. For permanent installations, the LD series monitor provides safety against the build-up of toxic gases in potentially hazardous areas. Five basic versions are available for continuously monitoring the same gases (individually) as the portable analysers.The units are packaged in thermostatically controlled, dust-proof and water-proof enclosures and are normally pro- vided with audio - visual outputs for remote alarm signalling. The alarm set-point is continuously adjustable throughout the full scale range of the analyser. A multi-point sequential sampling unit can be provided with any LD series model when it is necessary t o monitor a large area.Detection Instruments Ltd., 3 Rectory Road, Wokingham, Berkshire, RG11 1D J. Infrared Multi - sampler A fully automatic multi-sampler for use with any of their existing range of infrared spectro- meters has been introduced by Perkin-Elmer. The multi-sampler is fully integrated electronic- ally with the scan controls of the instrument and accommodates thirty potassium bromide discs or films.The disc and film holders are designed for easy loading and protecton of the sample. The standard disc holder takes a normal 1-mm disc; there is a special version for discs up to 1.5 mm. The unit is compact enough to allow the sample chamber lid to be closed during operation, so that purging with dry air or nitro- gen is possible if required. This is a useful facility when water-sensitive samples are being analysed. The ability to run thirty samples automatic- ally achieves a considerable saving in operator time and also permits overnight operation.Used in conjunction with Perkin-Elmer’s 580 computer systems, a pre-programmed tape enables samples to be run unattended over different wavelength regions and under different spectral conditions, with automatic processing of results.Perkin-Elmer Ltd., Beaconsfield, Bucks.94 EQUIPMENT NEWS Proc. Analyt. Div. Chem. SOC. Infrared Spectrometer A new addition to the 97 series of infrared spectrometers is announced by Perkin-Elmer. The Model 597 is a high-energy, double-beam optical null spectrometer with an extended wavelength range of 4 000-200 cm-1. Four scan speeds are offered, three slit programmes and a time-drive facility allowing transmission changes with time to be recorded on the instru- ment's own flow-chart recorder.It is fully compatible with Perkin-Elmer's new multi- sampler. For analyses in the region 250-200cm-l, where dry air - nitrogen purging is recom- mended, the sample compartment has been fitted with a sliding lid. A check gain control allows gain to be accurately and reproducibly set, even when the lid is closed and a sample is in the beam.Two chart formats are offered with the Model 597, so that spectra are com- patible with most existing filing systems. Perkin-Elmer Ltd., Beaconsfield, Bucks. Gas chromatography - Mass Spectrometer System The Hewlett-Packard HP 5992A GC - MS system is a comprehensive operating unit consisting of two modules.One is the controller, consisting of an HP9825 A calculator plus an HP9866 B printer - plotter. A second module contains a gas chromatograph, electron ionisation source, hyperbolic quadrupole mass analyser, electron multiplier detector, power supply and vacuum system. A GC - MS membrane interface is also contained in the single integral unit.The HP9825 A calculator has 16k words (16 bits each) of semiconductor memory. It has two built-in output devices, a 32-character display and an alphanumeric tape printer 16 characters wide, which prints a t 190 lines min-l. On top of the calculator is mounted the H P 9866 B thermal printer - plotter, having a 232- mm page width, which prints an 80-character column a t 250 lines min-l. The software supplied includes routines that calibrate and tune the system automatically, perform standard GC - MS experiments, do selected ion monitoring and plot and tabulate normalised spectra and includes a simple algebraic language permitting users to write their own programmes.The GC has an H P 5700 A series oven with microprocessor control of inj ection-port tem- perature.The standard column supplied is a 74 cm, 6 mm o.d., 2 mm i.d. glass column packed with 2% OV-101 plus 0.2% Carbowax 20M on Chromosorb W-HP. A 6 mm 0.d. glass column can be inserted directly into the septum area for "on-column" injections if desired. Oven temperature control is from -50 to +350 "C, with the sub-ambient option installed. Actual temperatures are stable to 0.1 yo of the set point and repeatable to better than 0.5 "C.A temperature programmer is fitted with initial and final times settable from 0 to 31 min. Oven rate is programmable from Q to 16 "C per minute in + "C steps, The injection port temperature ranges from 100 to 370 "C in steps of 2 "C. Actual temperature is stable to better than 0.1 yo of set point.The MS system has a range of 10-800 a.m.u. Unit resolution through the mass range is automatic under the calculator control. The isotope peaks in perfluorotributylamine are used as measurement criteria a t m/e 70, 220 and 503. Sensitivity for 1 ng of methyl stearate injected into the gas chromatograph will yield a spectrum with a 1O:l signal noise ratio on the molecular ion peak a t 298.3.The average noise between mass peaks is determined by a special pro- gramme. Full spectra can be scanned a t 600, 250, 125 and 62.5 a.m.u. s-1 from high to low mass in steps of 0.1 a.m.u. The ion source is a high-efficiency electron- impact type with two rhenium filaments. Electron energy is 70 eV. A continuous dynode electron multiplier is employed as the detector.The 3-kV power supply is under calculator control. The vacuum system includes pro- vision for automatic control of the pump and venting with a four-stage, water-cooled diffusion pump. This system is backed by a direct drive mechanical pump with a molecular sieve trap and solenoid-operated anti-siphon valve. Comprehensive safety features, to protect both the operator and the instrument, are incorporated into the system.Hewlett-Packard Ltd., King Street Lane, Winnersh, Wokingham, Berks., RG11 5AR. Modular Clean Benches For critical applications, such as the treatment of thin films, assembly of optical components and particle size analysis, Gelman Hawksley have introduced a range of laminar airflow work benches. These are particularly useful in pharmaceutical applications, sterility testing, tissue-culture preparation and drug formulation. All benches are tested to better than class 100 with the Royco 245 particle counter.The modular design allows units to be used individu- ally or joined together to form longer benches. Gelman Hawksley Ltd., 12 Peter Road, Lancing, Sussex, BN15 8TH.April, 1977' EQUIPMENT NEWS 95 Stereomicroscopes Cambridge Technology have established a world-wide marketing agreement with Focon Instruments for the recently released universal motorised focus and zoom control for stereo- microscopes.This system controls the opera- tion of the microscope by means of a foot switch, leaving the hands entirely free for manipulation of specimens. This facility should be of con- siderable value in the fields of medicine, biology and semiconductor technology.Cambridge Technology Consultant Co., Chesterton Mill, French's Road, Cambridge, CB4 3ND. Laboratory Temperature Control Equip- ment Techne Ltd. have introduced the TU 14 Tempunit offering 0.005 "C precision for -20 to + 180 "C. Independent safety cut-outs and variable/pre-set temperature control function are incorporated.The TE-7 Tempette, with 0.02 "C control over the range 0-80 "C, for water-bath applications is also announced. A comprehensive range of thermostatic water- baths (TWB series), Dri-block (DB series) and fluidised baths is also available. Techne (Cambridge) Ltd., Duxford, Cam- bridge, CB2 4PZ. High- performance Thin-layer Chromato - Recent developments in HPLC have paved the way for similar advances in thin-layer chroma- tography.Merck have now introduced HPTLC pre-coated plates capable of detecting nanogram amounts (or picogram amounts, with fluores- cence quenching) of a wide variety of materials. The new HPTLC plates feature a much nar- rower particle size range, thinner coatings and a high resolution resulting from smaller theoretical plate height.As the sample loading for optimum separation is smaller than for normal plates, a larger number of tests per plate can be achieved. BDH Chemicals Ltd., Poole, Dorset, BH12 4NK. graPhY Automatic Moisture Balance The Ohaus automatic infrared moisture balance has been added to the Gallenkamp range. This balance has a capacity of 10 g, sensitivity of 0.01 g and a tare of 5 g. Both mass and per- centage (to 0.1%) moisture loss are simultane- ously displayed throughout the drying cycle by projection of an optical scale (with vernier) on to a screen.The balance is magnetically damped, while the 150-mm balance pan is stabilised to eliminate tipping and off -centre loading errors. Heating power is variable from 0 to 375 W, so that intensity is easily controll- able.Sample heating can be controlled auto- matically for periods between 0.5 and 60 min, after which an alarm sounds and the heater is switched off. Sample heating is by means of a tungsten-filament lamp and reflector, which are adjustable in a vertical plane. A. Gallenkamp & Co. Ltd., P.O. Box 290, Christopher Street, London, EC2P 2ER. Digital pH Meters Gallenkamp have added two new Pye - Unicam digital pH meters to their range. The Model 9410 covers the full pH range, with an accuracy of 0.01 pH unit.Drift is within f 1 digit a t constant temperature and temperature com- pensation is controllable manually over the range 0-100°C. For research work of the highest accuracy, the Model 9409 has a normal reading to 0.01 unit over the whole range, and an expanded range from 6-8 pH units reading to 0.001 unit.Voltage measurements are also possible in the range f 2 V or -j= 200 mV (to f 1 mV and f 0.1 mV, respectively). Tem- perature compensation is automatic from - 10 to + 150 "C, or can be controlled manually from 0 to 100 "C. Both models are suitable for earthed or isolated solutions, and are supplied with a Type 401 E7 combined glass - reference electrode.A. Gallenkamp & Co. Ltd., P.O. Box 290, Christopher Street, London, EC2P 2ER. Automated X-ray Powder Diffractometer The Philips APD 10 fully automated XRD system provides fast and accurate qualitative and quantitative analysis of polycrystalline samples. Up to 35 samples can be run un- attended. The system consists of a Philips 3-kW generator and vertical goniometer, a graphite monochromator, together with sample changer, associated controls and a chart recorder.Additional automation facilities are con- trolled by a mini-computer, using plain language commands via a teletypewriter. A dual-station cassette unit enables measurement data to be collected for off-line processing on a larger computer . Software available includes : "Peak Search" (with or without KA2 stripping) with output confirmed by JCPDS search file ; data collection, in any conventionally used parameters with output on typewriter, chart or cassette, line profile with data recorded as net intensity and96 EQUIPMENT NEWS Proc.Analyt. Div. Chem. SOC. background against 28 (crystallite size distribu- tion and crystallite strain can be measured in this mode) ; and quantitative analysis, using either internal or external standards.Up to 99 programmes can be stored, depending on length, all immediately selectable. Philips new generation XRD tubes are fitted as standard for complete APD 10 systems; the much higher X-ray intensity results in greatly reduced measurement time. Users’ existing manual powder diffractometry equipment can be easily updated by adding the APD 10 automation facilities.Pye Unicam Ltd., York Street, Cambridge. Emission Spectrometer The PV 8350 is a direct-reading emission spectro- meter recently introduced by Philips/MBLE. The concentrations of up to 20 elements, includ- ing carbon, sulphur and phosphorus, can be determined simultaneously in materials such as steel, iron and non-ferrous alloys. A combina- tion of advanced optical and electronic design ensures good analytical performance and stabil- ity.The high resolving power blazed grating optics of l-m radius cover the wavelength range 1 770-4 100 A in the first order, a t a reciprocal dispersion of 4.63 a nm-l. The 50-Hz mono- alternance source unit generates a discharge of greatly improved reproducibility.The PV 8350 vacuum spectrometer and its complete electronics are installed in a compact unit (65 x 69 x 49&in). The notable thermal and mechanical stability of the spectrometer are achieved by mounting the complete optical system independently within the vacuum enclosure. Running under the automatic control of a number of pre-selected programmes ensures simplicity of operation, and the excitation stand can accommodate samples of a wide range of dimensions.The electronics can provide an automatic printout of the measured intensity values via a digital printer. There are also alternative electronics for a teletype printout and adapta- tion to computer control with direct readout in concentration. Pye Unicam Ltd., York Street, Cambridge.Flame Photometry One of the best known and successful analytical instruments, the EEL Model 100 flame photo- meter, has been updated and re-launched as the Model 400 by Corning Medical, a division of Corning Glass Works. Since its introduction, in the mid 1940s, over 40 000 EEL flame photo- meters have been sold, many of the original ones still being in use. The new version offers in- creased accuracy and dependability provided by independent zero-gain controls and narrow band filters, which improve inter-element specificity.Automatic ignition is now incorporated. Read- out ranges are 3-100p.p.m. for sodium and potassium, and 5-100 p.p.m. for lithium. The fuel gas supply can be propane, butane or natural gas. Corning Ltd., Halstead, Essex, CO9 2DX.Polarography The Tacussel PRG5 pulse polarograph, manu- factured in France, is being marketed by Clandon Scientific Ltd. Used in combination with the Tacussel Polaromat programme, it is particularly suitable for the automatic deter- mination of toxic heavy metals in water. The Tacussel PRG5 is capable of a variety of analytical techniques, and is designed for acceptance of ancillary modules, which extend its scope of application.The programmer, sample feeder and computer for data processing are integral with the fully automated system. The PRG5 incorporates automatic scanning speed control, which is designed to improve the accuracy and definition of the peak height obtained by the technique of imposed constant amplitude pulses (differential pulse polaro- Clandon Scientific Ltd., Lysons Avenue, Ash graphy) * Vale, Aldershot, Surrey, GU12 5QF.Chromatography Automation System The HP 3385 A chromatography automation system, from Hewlett-Packard, enables labora- tories to add microprocessor controlled data handling and analysis capabilities to existing analogue output instrumentation. Applicable to both gas- and liquid-chromatographic sys- tems, the HP 3385 A consists of an inter-active keyboard-controlled terminal, with a printer/ plotter and a module containing the processor and magnetic card reader and recorder.The system handles one instrument at a time, but up to five can be connected by an input selector. Automatic re-calibration and the averaging of calibration data are standard features, and the ability to change parameters between runs allows for automatic sequencing for the analysis of different samples.Once the parameters have been set, the operator injects the sample and obtains a complete analytical report, including the chromatogram and calculated results, to- gether with a printout of data reduction para- meters and sample coding. If desired, operators can enter complete oper- ating instructions via the keyboard, edit. the programme and then record on magnetic cardsApril, 1977 CONFERENCES AND MEETINGS for subsequent re-use. The system offers ten time programmable functions for complete con- trol of integrator events, such as tangent skimm- ing and base-lines. Area slice data can be obtained from any part of a run as an alternative to peak times and areas for applications such as gel permeation chromatography and simulated distillation. Hewlett-Packard Ltd., King Street Lane, Winnersh, Wokingham, Berks., RG11 5AR. New Materials Bio-Rad Laboratories have introduced a new Quantimune T4 radioimmunoassay test system based on the solid-state support technique using Bio-Rad Immuno-beads. The beads are sup- plied lyophilised for reconstitution by the user and contain a blue dye,- which permits visual identification of the bound fraction throughout the procedure. Bio-Rad Laboratories Ltd., 27 Homesdale Road, Bromley, Kent, BR2 9LY. Pharmacia are marketing two new chromato- graphic products. Sephacryl S-200 superfine is a bead-form covalent polymer of dextran and methylene bisacrylamide for gel filtration of molecules (relative molecular mass 5 000- 260 000). Flow-rates as high as 30 cm h-l are claimed. Octyl- and phenyl-Sepharose CL-4B are gels designed for hydrophobic interaction chromatography. As they contain no charged groups they are not subject to interferingionic effects. Pharmacia (Great Britain) Ltd., Paramount House, 75 Uxbridge Road, London, W5 5SS. 97

ISSN:0306-1396    

DOI:10.1039/AD9771400092

出版商:RSC    

年代:1977

数据来源: RSC

摘要:

April, 1977 CONFERENCES AND MEETINGS 97 Conferences and Meetings CS Industrial Division (Process Technology Group) Symposium May 18, 1977, London A symposium on “Measurement and its Effect on Process Technology” will be held in the Scientific Societies Lecture Theatre, 23 Savile Row, London W. 1. The provisional programme includes the following : “Efficient Processing of Variable Raw Mater- ials Using On-stream Analysis,” by K.G. Carr-Brion. “What Should we Measure for Petrochemical Process Control?” by D. R. Deans. “The Role of Radioactive Tracers in Process Plant Evaluation,” by G. V. Evans.98 CONFERENCES “Quality Control and its Effect on Process Technology,’’ by R. F. Weir. “Measurement of Environmental Pollutants in the Factory and Public Sectors,” by E.King. It is hoped to have preprints of the papers available before the meeting for those who have registered to attend. For further details con- tact Mr. H. L. Bennister, Process Technology Group Secretary, The Chemical Society, Burl- ington House, Piccadilly, London W 1V OBN. British Independent Steel Producers Asso - ciation: 30th Chemists’ Conference June 1-2, 1977, Scarborough This conference will be held a t the Royal Hotel, Scarborough.In the first session (Wednesday morning) the speakers will be Dr. H. Hughes, Dr. F. Fitzgerald, Mr. P. Gale and Mr. J . Powell, while on Wednesday after- noon papers will be read by Mr. C. M. Davis, Drs. H. and C. Jackson and Dr. M. Hofton. Session three will take place on Thursday morning, when the speakers will be Mr.K. M. Bills and Mr. G. M. Holmes. Application forms can be obtained from Mr. K. Speight, British Steel Corporation, Sheffield Laboratories, Hoyle Street, Sheffield, S3 7EY. Lasers in Chemistry May 31- June 2, 1977, London An international conference on this subject will be held a t The Royal Institution, London, under the sponsorship of The Chemical Society, Institution of Electrical Engineers, Institute of Physics, Society of Chemical Industry and The Royal Institution.Analytical applications are likely to include pollution monitoring, com- bustion, Raman spectroscopy and process control. The conference organiser is Dr. Michael West, The Royal Institution, 21 Albemarle Street, London, W1X 6BS. Fourth SAC Conference J u l y 17-22, 1977, Birmingham This Conference, organised by the Analytical Division of the Chemical Society, will be held at the University of Birmingham.It will feature all aspects of Analytical Chemistry by means of lecture and poster presentations, discussions, exhibition of manufacturers’ equipment and workshop sessions. The scien- tific programme will be supported by a social programme and visits. Further details, and registration forms, can be obtained from the Secretary, Analytical AND MEETINGS Proc.Analyt. Div. Chem. Soc, Division, The Chemical Society, Burlington House, London, WlV OBN. 26th Annual Conference on Applications of X-ray Analysis August 3-5, 1977, Denver, Colorado, USA The 1977 Denver Conference on Applications of X-ray Analysis, the 26th in the series, will be held on the University of Denver campus.On the day preceding the conference, August 2, tutorial workshops on special aspects of X-ray diffraction and fluorescence analysis will be conducted. The emphasis of this year’s conference will be on X-ray fluorescence, and the invited plenary session will be “New X-ray Techniques in Chemical Analysis. ” Invited lectures will cover X-ray excited optical luminescence, X-ray lasers and the interdependence of X-ray fluorescence and diffraction data.Two special sessions, one on calibration and alignment for XRD and the other on XRF applications in metals and mining, will include contributed papers on those subjects. As in the past, papers including any aspect of X-ray or related analysis are solicited. Registration forms will be included in the programme, which will be distributed in May.To receive a programme, write to Mrs. Mildred Cain, Denver Research Institute, University of Denver, Denver, Colorado 80208, USA. Monitoring of Hazardous Gases in the Working Environment December 12-14, 1977, City University, London A 3-day international conference on “The Monitoring of Hazardous Gases in the Working Environment” will be held from Monday, December 12 to Wednesday, December 14,1977, at the City University.The meeting is being organised by The Chemical Society in con- junction with the Health and Safety Executive, the Electrical Research Association and the City University. The Conference will open with two Plenary Lectures outlining the use of gas-monitoring systems for promoting health and safety in the working environment.Thereafter, the pro- gramme will be directed towards the monitoring of flammable and toxic gases which are normally present in industrial and laboratory situations and are accidentally emitted into the atmos- phere, including such gases which may be formed in situ during fires. The Conference will not deal either with atmospheric pollution, or with techniques of gas measurement specific to process control.April, 1977 PUBLICATIONS RECEIVED The themes of the Conference are (a) monitor- ingand detection of flammable gases and vapours, and (b) monitoring and detection of toxic gases and vapours.Further information can be obtained from Dr. J. F. Gibson, The Chemical Society, Burlington House, London, W1V OBN. Sixth International Conference on Modern Trends in Activation Analysis 1980 Successful conferences on Modern Trends in Activation Analysis have been held in College Station, Texas (1961 and 1965), Washington (1968), Paris (1972) and Munich (1976).The 1980 meeting will deal with recent original work on techniques and applications of acti- vation analysis in many areas of science, technology and medicine. The conference will last for 3-5 days and will attract between 200 and 500 participants. A commercial exhibi- tion will be held concurrently with the con- ference. The proceedings of the conference will, as on previous occasions, be published in book form. The choice of a site for the conference will, it is hoped, be made early in 1978. Organisations or individuals wishing to be included in the consultations leading to the selection of a site are invited to apply for further information to Professor J . M. A. Lenihan, Department of Clinical Physics and Bio-Engineering, West of Scotland Health Boards, 11 West Graham Street, Glasgow, G4 9LF, Scotland. 99

ISSN:0306-1396    

DOI:10.1039/AD977140097b

出版商:RSC    

年代:1977

数据来源: RSC

摘要:

April, 1977 PUBLICATIONS RECEIVED 99 Publications Received Methods of Biochemical Analysis. Volume 23. Edited by David Glick. Pp. x + 435. New York, London, Sydney and Toronto: John Wiley. 1976. Price L19.20; $31. Electrochemical Stripping Analysis. FrantiSek Vydra, Karel Stulik and Eva JulAkovA. Translation Editor : Julian Tyson. Ellis Horwood Series in Analytical Chemistry. Pp. 283. Chichester : Ellis Horwood.Distri- buted by John Wiley, New York, London, Sydney and Toronto. 1976. Price L17.50; $33.25. Contamination Control in Trace Element Analysis. Morris Zief and James W. Mitchell. Chemical Analysis, Volume 47. Pp. xvi + 262. New York, London, Sydney and Toronto : John Wiley. 1976. Price L17.35; $28. Physical Chemistry of Surfaces. Third Edition. Arthur W.Adamson. Pp. xviii + 698. New York, London, Sydney and Toronto: John Wiley. 1976. Price fj17.35; $28.70. Organic Electronic Spectral Data. Volume XII. 1970. Edited by John P. Phillips, Henry Feuer and B. S. Thyagarajan. Pp. xiv + 1138. New York, London, Sydney and Toronto: John Wiley. 1976. Price fj33.25; $57. Reports on the Progress of Applied Chem- istey During 1975. Volume 60. Pp. viii + 696. Oxford, London, Edinburgh and Melbourne : Blackwell Scientific Publica- tions for the Society of Chemical Industry. 1976. Price k25. The Development of a Pesticide as a Com- plex Scientific Task. Researches Related to the Herbicide Buvinol Produced by the Budapest Chemical Works. A Monograph Published on the Occasion of the 100th Anniversary of the Budapest Chemical Works. Edited by LAszl6 BAnki. Budapest: Medicina. 1976.

ISSN:0306-1396    

DOI:10.1039/AD9771400099

出版商:RSC    

年代:1977

数据来源: RSC