摘要:

of the Society for Analytical Chemistry CONTENTS Proc. SOC. Analyt. Chem. Vol. 6 No. 5 Pages 11-94 Reports of Meetings . . . . 77 “Computer Applications” . . 78 “Surface Area Determination by Adsorption Methods” . . 83 “Preparation of Analytical Papers for Publication” . . . . 85 “The Analysis of Plastics Formu- lations” . . . . . . 86 “Analysis of Food Flavours” . . 88 Membership Changes . . . . 89 Papers Accepted for The Analyst 90 Publications Received . . . . 91 Not ices . . . . . . . . 92 Announcements . . . . . . 93 Forthcoming Meetings . Back cover May 1969 Vol. 6 No. 5 May 1969 PROCEEDINGS THE SOCIETY FOR ANALYTICAL CHEMISTRY OF Hon. Secretary of the Society W. H. C. Shaw President of the Society T. S. West Hon. Treasurer of the Society G. W. C. Milner Hon. Ass’stant Secretaries of the Society D.I. Coomber; D. W. Wilson Secretary Miss P. E. Hutchinson 9/10 SAVILE ROW LONDON WIX IAF Telephone 01-734 6205 Editor 1. B. Attrill Telephone 01-734 3419 Proceedings is published by The Society for Analytical Chemistry and distributed to all members of the Society and t o subscribers with The Analyst; subscriptions cannot be accepted for Proceedings alone. Single copies may be obtained direct from the Society’s Distribution Agents The Chemical Society Publications Sales Ofice Blackhorse Road Letchworth Herts. (NOT through Trade Agents) price 0 The Society for Analytical Chemistry 5s. post free. Remittances MUST accompany orders. supplement to Qfficial Standardised and Recommended Methods of Analysis Compiled and Edited by S. C. JOLLY B.Pharm. B.Sc. F.R.I.C.M.P.S. Pp. xiv + 424 In 1963 the Analytical Methods Committee of the Society f o r Analytical Chemistry published a collection of all its standardised methods of analysis and a comprehensive bibliography of official and recommended methods of analysis under the title “Official Standardised and Recommended Methods of Analysis.” Now 4 years later a Supplement t o this volume has been produced that contains the more recently standardised methods of analysis published by the Committee a re-written and re-set version of the bibliography and an index t o the main volume and t o the Supplement. All 44 sections of the bibliography i n the 1963 volume except that on Soils have been revised and a new section on Coffee has been added. The information in most of these sections is now correct up t o the end of 1966 and in some instances later; for no section i s the date earlier than June 1966. The comprehensive index provided covers those parts of the main volume that are still applicable and the whole of the Supplement. Copies of the Supplement are available at the following prices (post free)- To Members of the Society To non-mem bers f6 6s. Od. (U.S.A. $15.50) f7 7s. Od. (U.S.A. $18.25) from THE SOCIETY FOR ANALYTICAL CHEMISTRY Book Department 9/10 Savile Row London WIX IAF (or your usual bookseller)

ISSN:0037-9697    

DOI:10.1039/SA96906FX017

出版商:RSC    

年代:1969

数据来源: RSC

摘要:

94 THE SOCIETY FOR ANALYTICAL CHEMISTRY Forthcoming Meetings May Thursday 22nd BECKENHAM Friday 30th to Monday June 2nd SCARBOROUGH Saturday 31st RODE July Monday 14th to Friday 18th SHEFFIELD Monday 21st to Friday 25th BIRMINGHAM BIOLOGICAL METHODS GROUP Summer Meeting. Visit to the Wellcome Research Laboratories Langley Court Beckenham. NORTH OF ENGLAND SECTION Summer Meeting. Satwday 10.30 a.m. “Evolution of the Ice Cream Industry,” by K. A. Hyde. Castle Hotel Scarborough. WESTERN SECTION Slimmer Meeting on “Industrial Archaeology of the Cloth Industry.” Speaker and guide K. Hudson. Including visits to Trowbridge and Bradford-on- Avon. Sportsman Steak House Rode ; 12.30 p.m. ATOMIC ABSORPTION SPECTROSCOPY GROUP jointly with the Spectroscopy Group of the Institute of Physics International Atomic Absorption Spectroscopy Conference.The University Sheffield. MIDLANDS SECTION International Symposium on Analytical Chemistry. The University Birmingham. Methods for the Analysis of Non-Soapy Detergent (NSD) Products by G. F. LONGMAN B.Sc. F.R.I.C. & J. HILTON B.Sc. A.R.I.C. (Unilever Research Laboratory Port Sunlight) Society for Analytical Chemistry Monograph No. I -0- This Monograph describes in detail the methods of analysis developed in Unilever’s Laboratories for the identification and assay of components of NSD Products. -0- Available ONLY from The Society for Analytical Chemistry Book Department 9/10 Savile Row London W. I. (Not through Trade Agents) Price 15s. or U.S. $2.00 Post free A remittance made out t o “Society for Analytical Chemistry” should accompany every order. Members of the Society may purchase copies at the special price of 5s. post free. Printed by W Heffer h Sons Ltd Cambridge England

ISSN:0037-9697    

DOI:10.1039/SA96906BX019

出版商:RSC    

年代:1969

数据来源: RSC

摘要:

May 1969 Vol. 6 No. 5 PROCEEDINGS OF THE SOCIETY FOR ANALYTICAL CHEMISTRY 1969 List of Members The List of Members is due to be reprinted this year. Members are asked to notify the Secretary as soon as possible and in any case by July lst 1969 of any changes to their entry in the 1967 List of Members. All those who indicated changes to their address on their 1969 subscription form need not write again. Reports of Meetings ORDINARY MEETING AN Ordinary Meeting of the Society was held at 2.30 p.ni. on Thursday May 8th 1969 in the Department of Chemistry The Queen’s University David Keir Building Belfast 9. The Chair was taken by Mr. C. A. Johnson Vice-president of the Society. The Meeting was devoted to short papers on “Research Topics in Analytical Chemistry” and the following papers were presented and discussed “The Analytical Chemistry of Bithionol and its Metal Complexes,” by A.Gray A. G. Fogg and D. Thorburn Burns; “A Highly Sensitive Method for the Determination of Arsenic,” by C. A. Watson ; “Some Coulometric and Volumetric Acid - Base Titrations in Semi-aqueous Media,” by D. W. Whymark and J. M. Ottaway; “The Applications of the Chemiluminescence of Renzazoles,” by A. Rixon and L. S. Bark; “What Happens When Solutions of Dithizone Deteriorate,” by D. C. Rupainwar and Professor H. M. N. H. Irving; “A Study of Salicylideneamino-2-thiophenol Some Related Compounds and Their Tin Complexes,” by Mrs. Jean Kingshott ; “The Determination of Trace Amounts of Calcium in Stainless Steels by Solvent Extraction followed by Atomic- absorption Spectrometry,” by J. Richardson ; “Analytical Utility of the Metal Complexes of Alizarin Fluorine Blue,” by M.A. Leonard and IT;. I. Nagi. The meeting was followed on Friday May 9th by visits to the Old Rushmills Distillery and the New University of Ulster Coleraine. NORTH OF ENGLAND SECTION A JOINT Meeting of the Section with the North Lancashire Section of the Royal Institute of Chemistry was held at 7.30 p.m. on Friday April 18th 1969 in the Harris Technical College Preston. The Chair was taken by the Chairman of the North of England Section Mr. R. Sinar. A lecture on “Chromatographic Methods of Pesticide Residue Analysis,” was given by J. O’G. Tatton. SCOTTISH SECTION AND CHROMATOGRAPHY AND ELECTROPHORESIS GROUP A JOINT Meeting of the Scottish Section and the Chromatography and Electrophoresis Group was held at 11 a.m.on Friday April 25th 1969 at the Royal Society of Edinburgh 22-24 George Street Edinburgh 2. The subject of the meeting was “Chromatography” and papers were presented and discussed in two sessions. Morning Session at which the Chair was taken by the Chairman of the Scottish Section Dr. D. M. W. Anderson “Laminar Chromatographic Studies of the Wool-epicuticle and Amino-acids,” by E. V. Truter ; “Thin-layer Chromatography of Plant Phenolics,” by J. M. Philp. Afternoon Session at which the Chair was taken by Dr. E. V. Truter “Non-aqueous Ion Exchange of Weak Organic Acids,” by J. D. R. Thomas; “The Application of Gas - Liquid Chromatography to the Detection of Pollutants in Rivers,” by A. W. navies; “The K Concept,” by L. S. Bark; “Molecular Sieve Chromatography,” by D.M. W. Anderson. 77 78 REPORTS OF MEETINGS [PYOC. SOC. ,4.tznlyt. Chem. A DISCUSSION Meeting of the Section was held at 6.30 p.m. on Friday April 18th 1969 at the George Hotel Chepstow. The Chair was taken by the Vice-chairman of the Section Dr. T. G. Morris. A discussion on “Electrical Methods of Analysis” was introduced by G. W. C. Milner assisted by A. J. Wood G. Phillips and R. H. Davies. MIDLANDS SECTION A JOINT Meeting of the Section with the Mid-Anglia Section of the Royal Institute of Chem- istry was held at 6-45 p.m. on Wednesday April 16th 1969 at the Luton College of Tech- nology Park Square Luton. The Chair was taken by the Chairman of the Midlands Section Mr. W. M. Lewis. The following paper was presented and discussed “Non-dispersive X-ray Fluorescence Analysis,” by T.W. Packer. NORTH EAST SECTION A JOINT Meeting of the North East Section with the Teesside Section of the Royal Institute of Chemistry was held at 8 p.m. on Tuesday April 22nd 1969 in the Constantine College of Technology Borough Road Middlesbrough. The Chair was taken by the Chairman of the Teesside Section of the Royal Institute of Chemistry. Dr. P. Smith. WESTERN SECTION A lecture on “The Work of a Textile Chemical Consultant,” was given by W. Garner. BIOLOGICAL METHODS GROUP AN Ordinary Meeting of the Group was held at 7 p.m. on Thursday April 24th 1969 at the Pharmaceutical Society 17 Bloomsbury Square London W.C.I. The Chair was taken by the Chairman of the Group Dr. I. D. Fleming. A lecture on “Recent Advances in the Assay of Vitamin B, and its Co-enzymes,” was given by L. Mervyn. RADIOCHEMICAL METHODS GROUP AN Ordinary Meeting of the Group was held at 10.30 a.m. on Tuesday April 29th 1969 at the Borough Polyteclinic Borough Road London S.E.l. The Chair was taken by the Chairman of the Group Dr. H. J. M. Bowen. The subject of the meeting was “The Uses and Measurement of Tritium” and the follow- ing papers were presented and discussed “Problems Peculiar to the Use and Misuse of Tritium Compounds,” by E. A. Evans; “The Measurement of Tritium,” by R. D. Stubbs; “Tritium in Autoradiography,” by S. R. Pelc; “Low Level Tritium Measurements,” by R. L. Otlet; “Industrial Uses of Tritium,” by I>. S. Glass; “The Uses and Measurement of Tritium in Steroid Biochemistry,” by I. Sonimerville ; “The Use of Tritium in Investigating the Origin of Milk Fat,” by R. F. Glascock.

ISSN:0037-9697    

DOI:10.1039/SA9690600077

出版商:RSC    

年代:1969

数据来源: RSC

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78 REPORTS OF MEETINGS [Proc. SOC. ,4.tznlyt. Chem. Computer Applications The following are summaries of the papers presented at a Meeting of the Society held on November 6th 1968 and reported in the November 1968 issue of Proceedings (p. 215). Introduction to Computers BY R. K. WEBSTER (Analytical R. and D. Uuzit 3.148 Atomic Enevgy Research Establishment Hawell Didcot Bevks.) A BASIC introduction to computing was given to provide a background for the papers on specific computer applications. Broadly this introduction surveyed how computers work ; how they are programmed; typical applications and methods of data entry; and the range of sizes of computer installations and the corresponding costs. Various terms of “computer dialect” were also covered including on-line off -line hard-ware soft-ware bit word address accumulator core-store backing store cycle time data-break program interrupt machine code binary octal and Fortran.May 19691 COMPUTER APPLICATIONS 79 A computer functions by following a sequence of stored instructions to operate on stored data and can be illustrated by analogy with a human operator “programmed” to read and carry out a sequence of written instructions stored on strips of paper in successive locations of a nest of pigeon holes. Computers normally use binary storage as many electronic storage units are two-state devices; for example one “bit” of information can be stored in a ferrite ring by magnetising it either clockwise or anticlockwise to represent and store “0” or “1,” respec- tively and hence a set of ferrite cores can be used to store the various bits or binary digits of a complete binary number or computer word.A three-dimensional matrix of ferrite rings provides a compact high-capacity core store. Rapid access and control is based on storage in registers made up as a series of “flip-flops” (two-state devices available as integrated circuits). The layout of a binary instruction varies between different computers but typically one part codes the required arithmetic or logical operation and the other part codes the address or location of the section of the ferrite store containing the data to be manipulated. Instruc- tions and numerical data are both stored as binary bit patterns and differ only in how they are interpreted during the operation of the computer. The address of the ferrite store containing the next computer instruction to be followed is held in a register usually called the Program Counter.In operation each instruction takes the form of a sequence of actions triggered by timing pulses typically as follows the contents of the program counter are transferred to a memory address register which sets the circuits for transfer of the required instruction from the ferrite-core store to a memory buffer register (and at this point the program counter is usually incremented so that it is set ready to select the next instruction in the sequence); the binary instruction is trans- ferred from the buffer register to the instruction register where part is de-coded to bring in the appropriate arithmetic unit and the other part transferred to the memory address register to set the circuits for transfer of the required data from the ferrite-core store to the memory buffer register.At this point the required arithmetic operation is applied to the selected data word and the result typically stored in the accumulator register. This com- pletes one operation or computer cycle and leaves the program counter set ready to initiate the next instruction. The cycle time varies with the computer but is typically about 1 psecond. In principle a program can be entered into a computer by setting each binary instruc- tion in turn with a row of toggle switches on the computer console but in practice it is norm- ally read in from a “Teleprinter,” a paper tape reader a punched card reader or from magnetic tape-in each case the computer must contain the appropriate binary program to interpret the information from the selected peripheral.Programs can be written as binary or octal instructions or more simply by using for each instruction an easily remembered mnemonic for the required operation (e.g. for add store jump etc) and for the data location (e.g. A B and C for a sequence of instructions constructed to carry out C = A + U). An assembler program supplied with the computer is required to translate the mnemonics into the corresponding binary instructions. Higher level languages (Autocode Fortran Algol Cobol etc) enable programs to be written as a sequence of almost standard algebraic equations; for example for calculating the area of a triangle of sides of length A B and C the two main instructions of the program would be SUM IT= (A + 13 + C)/2*0 AREA = SQRT (SUM* (SUM-A) * (SUM-B) * (SUM-C)) Again a compiler program supplied with the computer is required to transform each of these algebraic statements into a sequence of binary instructions.In off-line applications both data and a program are coded on punched tape or cards or on magnetic tape and processed some time later by a central computer service. Typical applications include scientific calculations assessment of management information and literature or information retrieval. Off -line processing can also be used for interpretation of spectra and other instrumental data but the inevitable time delay may cause inefficient use of scientific instruments. This difficulty can be avoided by connecting a small computer directly to the instrument. (i) Data acquisitiwz-For example for nuclear magnetic resonance electron spin resonance infrared and mass spectrometry where spectra are digitised and then stored added or averaged in the magnetic core store.On-line applications include the following. 80 COMPUTER APPLICATIONS [Proc. SOC. Analyt. Chem. (ii) Data wmni@dation-Calculations can be made when data acquisition is complete by a change of program ; alternatively with a suitable computer some calculations can be carried out at the same time as data acquisition and sufficiently quickly to keep pace with the incoming data this is called real time processing and its use for reducing the large volume of data from organic mass spectrometry to a more manageable level is described in the following paper. (iii) Instrument control-When the computer monitors instrumental settings and when necessary applies adjustments ; potential applications range from maintaining magnetic field homogeneity for nuclear magnetic resonance spectrometry to complete control of a cyclotron.For on-line applications instrumental data is entered directly into the computer in one of two general ways. For relatively slow data rates (e.g. up to about 1kHz) the instrument generates a program interrupt signal when data is ready for transfer. On sensing this signal the computer jumps from the current program in operation to a separate sequence of pro- gram instructions designed to store or manipulate the incoming data and when this is complete the computer returns to the next program instruction of its original task. High speed data transfer (50 to 100 kHz) is effected by a data-break system on sensing a data-break request from the instrument the computer “hesitates” at the end of the next program instruction or computer cycle and data is transferred directly to the ferrite-core store by special circuitry quite independently of the computer program.When transfer is com- plete (typically 1 to 3 cycles) the computer continues with the next instruction. This tech- nique or facility is known variously as direct memory access autonomous data transfer and cycle-stealing. Computer word lengths vary from 12 bits upwards and computer core stores range from 4000 words to perhaps lo5 to lo6. In addition to printers paper tape or card punches and readers and magnetic tape units peripheral devices may include a magnetic disc or drum to provide fairly rapid random access to perhaps 1 to 100 million words used for storage of alternative pro- grams reference data and so on.Although a comprehensive computer system is extremely expensive small computers are available in the Leo00 to E4000 range both for calculation and for on-line instrumental applica- tions. Calculations can be carried out by submitting data and programs on cards or tapes to a computer bureau; charges vary with the performance and capacity of the computer used ranging from Cis. to E6 per minute. Alternatively a Teletype terminal can be installed on a monthly rental basis in any individual office or laboratory and connected as required by a standard telephone link. The size of computer installation clearly varies with the application. Application of an On-line Computer to Mass Spectrometry BY D.J. SHIELDS (Imperial Chemical Industries Ltd. Mond Division Reseavch and Development Depavtment The Heath Runcovfi) A SYSTEM is outlined that processes the output of an A.E.I. MS9 double-focusing mass spectro- meter by use of a Ferranti Argus 300 con1puter.l The computer system has been designed to accept the output of the spectrometer scanning rapidly (10 seconds per mass decade) and at high resolution (about 10,000 10 per cent. valley definition). Programs have been devised which calculate the precise masses of all ions in the spectrum within 1 minute of the end of the scan. The system extracts all of the data available in a high resolution mass spectrum in a single scan. Previously to obtain such data by using conventional manual methods of precise mass measurement would have taken about 10 minutes per peak.In a complex spectrum there may be in excess of 500 peaks and attention had to be directed to only a few ions selected by a study of the low resolution spectrum. It was therefore always necessary to introduce the sample into the spectrometer twice and frequently even more often when the first selection of peaks for accurate measurement proved inadequate. Also many of the compounds examined routinely can only be held in the spectrometer for about 30 seconds. On such samples precise manual measurements were particularly difficult. Such methods May 19691 COMPUTER APPLICATIONS 81 were wasteful of skilled effort. When samples consisted of the minute trapping from a gas - liquid chromatographic column a second introduction of sample might require a second collection.Data processing is carried out as follows. The output of the spectrometer is fed via a sample and hold amplifier to an analogue- to-digital converter. Irregularities of peak shape arising from poor ion statistics dictate that at least twenty digital samples must be taken over a peak width so that the peak centre can be defined with satisfactory precision. At the scan rate and resolution used this involves a digitisation rate of about 50,000 per second. In a 10-second scan therefore 500,000 digital samples would be taken and as the Argus 300 computer used has only 8192 locations of core store on-line data reduction is essential. This is achieved by incorporating a digital com- parator which inhibits the recording of those samples that fall below a pre-set threshold.This threshold is set at such a level that all samples between peaks are rejected. So that the time scale is not lost special purpose logic is included which recognises the end of each peak (k when the current sample is below threshold the previous sample having been above it). At such times the value of the sample number counter which is increased by one after every digitisation is inserted into core store. Samples and count numbers are inserted into core store via a direct store access (D.S.A.) system i.e. independently of program. During a mass-spectrometer scan the program being obeyed is examining the region of core store allocated to D.S.A. As each peak arrives in core the program calculates the peak centroid and intensity. In general this computation will be completed before the mass spectrometer has scanned to the next mass number.To cater for closely spaced multiplet peaks however the program allows a queue of peaks to be accommodated. At the end of the mass-spectrometer scan the centres and intensities of all the peaks in the spectrum are stored. The program then establishes the mass scale of the scan by identi- fying which of the peaks in the spectrum are due to reference compound and then interpolating for the masses of the remainder which are due to the sample. Output is on paper tape and printer. The masses so computed are accurate to within 6 p.p.m. which is usually sufficient to allow unambiguous assignment of elemental composition. Programs have been written that read the accurate masses computed by the on-line program and convert them into elemental compositions.Often however such a wealth of information is available from a complete high resolution mass spectrum that the spectroscopist may be overwhelmed and for such complex spectra programs have been developed that not only identify the ions in the spectra but lay out the ionic compositions as an element map a format most amenable to interpretation by the spectroscopist. REFERENCE 1. Bowen €1. C. Clayton E. Shields D. J. and Stanier H. M, “Advances in Mass Spectrometry,” Volume 4 Institute of Petroleum London 1968 p. 257. Data Handling of Gas Chromatograms of Cigarette Smoke BY K. D. KILBURN (Reseavch and Development Establishment Bvitish-Amevicaw Tobacco Co. Ltd. Regent’s Pavk Road Southamp ton) THE data handling of gas-chromatographic analyses of tobacco smoke was discussed.The speaker emphasised that a data-handling system could not increase the amount of informa- tion contained within the chromatogram but it should increase the speed the ease the completeness and the reliability with which that information is extracted. The most important difference between the many proposed systems is in the extent to which they realise these advantages. Experience of applying data-handling techniques to one of the several analytical pro- cedures that had been used for analysing cigarette smoke was discussed. In this work cigarettes are smoked by a smoking machine and the smoke is collected in a cold trap. An internal standard is added to the trap and the contents are distilled at high vacuum from a special pot still. The distillate is chromatographed on a temperature-programmed poly- propylene glycol capillary column fitted with a flame-ionisation detector.82 COMPUTER APPLICATIONS [Proc. Soc. Analyt. Chem. Each chromatogram contains about 350 peaks from butane to a C, terpene and during the 7-hour chromatograni the peak widths increased from 1 to 300 seconds. The peak heights vary over a range of 1 to 30,000 and there are about 25 peaks in each unit carbon- number range. The greatest difficulty encountered when this analytical procedure was put into routine use was the high rate of human error. Measuring the chromatograins was extremely tedious and re-checking of results proved expensive but essential; hence the incentive to develop an automatic data-processing system. The original objective of the data-handling system was to provide a fully automatic analysis from sample injections to report preparation.The first hurdle to be overcome was that of recognising corresponding peaks on a pair of chromatograms. It was found that a carbon-number scale based on the methyl n-alkyl ketone was stable and that provided peak retentions were accurately determined computer-calculated carbon numbers were reproducible to within 50.004 carbon number. As the chromatograms were primarily to be used for intercomparison reproducibility was more important than accuracy. It was essential therefore to determine the beginning and end of a peak as well as the base-line position to ensure comparability. When the project was started the most promising automatic technique was data logging followed by computer processing.It was correctly predicted that at a data-logging rate of 16 to 30 points per peak the quantitative reproducibility should not be degraded by more than 0.3 per cent. and the carbon-number precision should not be degraded at all. The method that was developed enabled all of the peaks and shoulders that could be seen on a chart chromatogram to be detected. Details of this method have been given e1sewhere.l Determining peak areas was more difficult. The advantages and disadvantages of this approach were then described. By adopting this technique an enormous improvement was achieved in the standard of chromatography and the final results are reliable. Operator errors become glaringly obvious as do normally unnoticed deteriorations in chromatograph performance. All the results are calculated on every chromatogram and many findings have been made that would otherwise have passed unnoticed.The experimental work can be carried out by fewer staff because the total work-load is reduced by 80 per cent. However instrument availability tends to drop mainly because any malfunctioning becomes apparent sooner but also because of the increased complexity of the system. The data-logging system itself has given little trouble. Human error is usually obvious whether it be a faulty reading on a punched card or a paper tape read back to front but it results in irritating delays. Verification of the results is still required even although this is usually a quick simple process. Returning now to a further consideration of the data-handling problem the speed with which reliable analytical data could be produced exceeded the rate at which it could be interpreted.Typically one investigation would yield several thousand items of data which required collation chemical identification and interpretation. This has been examined and a computer program has been developed to identify the peaks. The criterion for identity was arbitrarily defined as the average carbon number (C.N.) & one quarter of a peak width. On these chromatograms one quarter of a peak width corre- sponded to one hundredth of a carbon number. This error gate allowed for normal random experimental error arising from flow and temperature variations. However systematic errors due to the nature of the sample were also found that were dependent on functional groups; for example on one chromatogram all of the nitriles might be 0.01 C.N.early. Thus cases were found in which compounds drifted by 0.015 C.N. and were placed outside the normal error gate. The computer program finally developed prepares and updates a library of carbon number and detector-response factors from chromatograms of standard mixtures and then makes use of the data to identify compounds in cigarette smoke with a stated probability based on an extended series of error gates. This program together with another involving automatic collation techniques has May 19691 SURFACE AREA DETERMINATION BY ADSORPTION METHODS 83 been most useful. One set of analyses that had taken 12 weeks to interpret was indepen- dently interpreted in 1 day with the help of these programs. This was a particularly favourable example but it illustrates the power of this approach.It is difficult to give accurate assessments of effort devoted to specific aspects of a job especially in a laboratory in which several experiments are interleaved but Table I sum- marises our experience of the advantages to be gained. TABLE I WORKING TIME (DAYS) ON A PER CHROMATOGRAM BASIS Qualification Smoke and Chromato- Processing level distil graphy Graduate O-Levels 1 1 Graduate Computer LRlC or assisted HNC 1 0.1 Manual LRlCor HNC 1 O-T,evels 1 1 Calculate gas - liquid chromato- graphy Verify and results correct Interpret Report 2 2-6 1 4 2 3 15 3 0.5 1 0-5 0.2 2 1 The computer processing of the chromatograms saves mainly the effort at the middle and lower qualification levels while automatic interpretation saves mainly on graduate time and the latter aspect is considered to be the prime advantage of this type of data- handling system.This system cuts running costs by about two thirds. With regard to future developments the computer bureau we use is replacing its IBM 7094 computer with an IRM 360 Model 65. The need to run our programs efficiently on the new machine will mean considerable re-organisation of those programs and we are taking the opportunity to consolidate them into a single flexible data-handling system. A survey of our gas - liquid chromatographic data-handling requirements throughout the laboratories has shown that they fall into two distinct types. Firstly those simple chromatograms of well separated peaks that can be assessed by peak height measurements or the less sophisticated printing integrators and secondly those chromatograms of more than 10 peaks that could in principle benefit from the data- logging approach.To realise this benefit in practice will require extension of the existing programs to cope economically with many short chromatograms and extended solvent peaks and to calculate results with regard to percentage recovery data obtained from isotope-dilution experiments. In addition to these obvious improvements some success is being achieved in building a learning process into these programs to ensure that verification is a continuous and automatic function of the programs. Then all the processes from injection of samples up to the final report will be entirely automatic. REFERENCE 1. Dymond H. F. and Kilburn K. D. in Littlewood A. B. Editor “Gas Chromatography 1966,” Proceedings of the Sixth International Symposium Institute of Petroleum London 1967 p. 353.

ISSN:0037-9697    

DOI:10.1039/SA9690600078

出版商:RSC    

年代:1969

数据来源: RSC

摘要:

May 19691 SURFACE AREA DETERMINATION BY ADSORPTION METHODS 83 Surface Area Determination by Adsorption Methods The following are summaries of the papers presented at a Meeting of the Particle Size Analysis Group held on November 26th 1968 and reported in the February issue of PYoceedings (p . 17). Measurement of Specific Surface of Finely Divided Solids by Dye Adsorption BY C. H. GILES THE determination of the specific surface of finely divided solids especially powders is becoming of increasing importance in many industries. Many methods of measurement of the surface have been proposed; the most widely used can be classified as follows (i) use of (Pure and Applied Chemistry Department University of Strathclyde Cathedval Street Glasgow C. I ) 84 [Proc. SOC. Analyt. Chem. microscopy optical and electron; (ii) test of permeability usually with air but liquids can be used; and (iii) adsorption of a gas or solute.Adsorption of a gas particularly of nitrogen at liquid-air temperature has tended to become the most widely accepted method although other gases and vapours are sometimes used. The procedure and apparatus required however are complex and the method requires skilled operation. Adsorption of solutes from solution mainly surface-active compounds phenols or dyes has often been used. The method is simpler and more rapid than gas adsorption. Dyes and certain phenols especially P-nitrophenol are probably the most useful types of solute for this purpose as they are available in a great variety of molecular structures and their determination by spectro- photometry is simple and rapid.Their use although known for a long time has not been widely accepted because of the variability of the results obtained compared with those by nitrogen adsorption. Recent investigations in the speaker’s laboratory however have enabled a rapid simple and reliable method to be evolved that is suitable for many common powders and is adaptable for use on a semi-micro scale. The main causes of variability in previously reported results appear to have been (a) the effects of specific and non-specific solute - solid bonding; (b) association of dyes adsorbed by non-specific bonding; (c) interference by chemical reaction between dyes and the solid or adventitious ions introduced into the solution from the solid; and (d) micro porosity in some solids. Effect (d) causes the measured area to fall with increase in size of the dye molecule and enables an evaluation of the extent of micro porosity in the solid to be made from results obtained with p-nitrophenol and dyes of different molecular size.The results for the surface accessible to dyes may often be more realistic than those obtained by using gases as the latter measure areas in fine pores which may be inaccessible to most solutes that come into contact with the powder in technical practice. Suitable solutes for many common solids are p-nitrophenol which is adsorbed as single molecules either flatwise or end-on to the solid surface and methylene blue which is adsorbed flatwise as a dimer. The time required for a complete determination with one solute is about 70 minutes which can often be reduced to about 25 minutes by using a “one-point” method.These times exclude the period of tumbling required to attain equilibrium when of course the test requires no attention. This period is about 15 to 30 minutes for non-porous solids but may be 24 hours or longer with micro-porous materials. SURFACE AREA DETERMINATION BY ADSORPTION METHODS Determination of Surface Areas by Flow Calorimetry RY A. J. GROSZEK SURFACE areas of a wide range of polar solids can be determined rapidly in the flow calorimeter by percolating a dilute solution of n-butanol in n-heptane through a bed of the powdered solid immersed in n-heptane and measuring the total heat involved. The alcohol is adsorbed strongly on to the polar solids from non-polar liquids such as n-heptane and saturates the surface at a very low solution concentration.The saturation can be demonstrated strikingly by determining successively the heats of adsorption of the solu- tions containing gradually increasing concentrations of the solute. After the saturation further increases in solution concentration do not give any further heat of adsorption and the surface is then covered with a closely packed monolayer of n-butanol. The saturation of powders with n-hutanol in the flow micro calorimeter occurs with the simultaneous displacement of solvent from the interface and the process consists therefore oE two main steps in which the solute displaces the adsorbed solvent from the interface and forms a monolayer and the monolayer is covered by the solvent. The integral heat of preferential adsorption results when the above processes are completed.The heat is directly proportional to the number of adsorbed solute molecules and hence to the surface area occupied by these molecules. The proportionality constant in this relationship depends on the affinity of the solute for the surface and its orientation. The effect of orientation is shown by comparing the heats of preferential adsorption of n-butanol and n-octadecanol on iron oxides the long-chain alcohol giving considerably higher heats of adsorption per unit area than n-butanol. This is ascribed to vertical orientation of alkyl chains in the adsorbed n- octadecanol molecules which decreases their entropy. (Bvitish Pedvoleum Co. Ltd. B. P. Reseavch Centve Chevtsey Road Sunbuvy-on-Thames Middlesex) May 19691 PREPARATION OF ANALYTICAL PAPERS FOR PUBLICATION 85 The orientation of n-octadecanol varies considerably with its concentration in n-heptane and the adsorption isotherms for this alcohol are often without plateau regions.This makes the long-chain alcohol unsuitable for determinations of surface areas. The measurement of surface areas of individual surface sites by the flow calorimeter is illustrated by the determinations of polar and basal-plane sites in graphites. Generally graphite powders consist of particles with two different types of sites basal- plane and polar-edge sites. It has been found that these sites have different adsorptive properties. The basal-plane sites adsorb long-chain n-paraffins in preference to polar com- pounds whereas the polar sites exhibit the opposite behaviour i.e. they adsorb preferentially polar solutes from non-polar liquids.These properties were revealed clearly by studying the adsorption of n-dotriacontane and n-butanol from n-heptane on to different types of graphites. The adsorption of n-dotriacontane on the basal-plane sites of graphite can be used for the determination of the proportion of basal-plane surface in various graphites. As the integral heat of adsorption of n-dotriacontane from n-heptane is proportional to the amount of n- dotriacontane adsorbed from this solvent the heat of adsorption can be also used for the determination of the basal-plane area in graphites. Similarly the adsorption of n-butanol from n-heptane can be used for the determination of the area of polar sites in graphites. Determination of the polar and basal-plane surface areas in graphite powders can be carried out rapidly by successive percolation of dilute n-butanol and n-dotriacontane solutions in n-heptane through the same sample of powder n-butanol being desorbed with the pure solvent before the percolation of the long-chain paraen is commenced.

ISSN:0037-9697    

DOI:10.1039/SA9690600083

出版商:RSC    

年代:1969

数据来源: RSC

摘要:

May 19691 PREPARATION OF ANALYTICAL PAPERS FOR PUBLICATION 85 Preparation of Analytical Papers for Publication The following is a summary of one of the papers presented at a Meeting of the Society held on December 4th 1968 and reported in the December 1968 issue of Proceedings (p. 236). Essential Information for Quantitative Gravimetric Titrimetric and Instrumental Methods BY R. A. CHALMERS (Chemistry Department The University Old Aberdeen) THE background material to the paper should give the reasons for undertaking the work and these must be adequate e.g. no satisfactory method available existing methods too insensitive or non-selective. The development of the method must be described so that the chemistry and logic of the method can be understood. The purity (and how it was determined) as well as the impurity of the materials used especially the test samples and model substances must be specified.Makers and catalogue numbers of equipment or chemicals need not be given unless it is absolutely essential that a particular type be used-but in that case the method is not likely to command much popularity. Details must be given of examination of various factors such as the permissible pH range (buffers must be chosen to avoid side-reactions with metal ions; pH meters should preferably not be necessary in the procedure itself); stoicheiometry of reaction (inconvenient facts such as intermediate or mixed complexes should not be sup- pressed or glossed over) ; stability (thermodynamic and kinetic) of complexes ; tolerances on amounts of reagents added and time intervals used (split-second timing and exact reagent measurement are drawbacks) ; side-reactions and interferences of matrix elements with reagents and of determinand with matrix elements and reagents remembering the profound effect of inert mixed complexes (see H.M. N. H. Irving and W. R. Tomlinson I’alanta 1968,15 1267 and references therein) ; selectivity (not confined to a few common ions that do not form complexes or precipitates easily anyway and certainly including elements commonly occurring in association with the determinand in samples likely to be found in practice) ; sensitivity (with a definition of the criteria used); and indicator performance (in terms of sharpness speed accuracy and reversibility) . 86 THE ANALYSIS OF PLASTICS FORMULATIONS [PYOC. SOC. Amalyt. Chezut.The details of the procedure finally developed are often very important. The researcher has gradually and often unconsciously developed the technique to its highest pitch and a newcomer to it may not have the requisite expertise to obtain such good results. Apparently trivial details of procedure may be of paramount importance especially in such cases as dissolution of a cooled fusion melt that contains easily polymerised species. Detail should be adequate to maximise efficiency e.g. tolerances for weights and volumes of reagent. Instrument performance should be specified so that a suitable instrument can be selected for the job. Any special modifications should be described in full with details of circuitry (with values of resistors condensers etc.) or of dimensions for metal and glass work (given in metric units of course).Accuracy precision and dead-band characteristics of recorders are important (see D. A. Aaker AaaZyt. Chew. 1965 37 1252). Results must have a proper statistical assessment and a realistic appraisal of errors and of the limitations and abilities of the method. In gravimetric work care must be taken to check whether compensation of errors has arisen (see S. S. Berman P. Semeniuk and D. S. Russell Talaata 1966 13 887). A proper comparison must be made with results obtained by other methods and “real life” samples must be analysed to demonstrate the applicability of the method. Details of results need not be given unless they illustrate a particular point (e.g. a change in mechanism)-anyone who would disbelieve a statement would also disbelieve a graph or table of results! References MUST BE ACCURATE AND CHECKED AGAINST THE ORIGINAL LITERATURE BOTH The manuscript should contain all the information needed for the referee to evaluate the soundness of the underlying chemistry and of the conclusions reached but not all this informa- tion need necessarily be published.The reader must rely on the integrity and ability of the referee and editor and trust them to judge whether the method does what it claims to do and then to present as concisely as possible the essential details of the method its development and the results obtained with it. Failure to satisfy these requirements may result in others being unable to repeat the work with satisfactory results leading at best to the work being regarded as unreliable. A paper on the development and publication of new spectrophotometric methods of analysis has been published by G. F. Kirkbright (Talaata 1966 13 1). I am indebted to Dr. A. L. Wilson for sharing his ideas with me. I N MANUSCRIPT AND I N PROOF.

ISSN:0037-9697    

DOI:10.1039/SA9690600085

出版商:RSC    

年代:1969

数据来源: RSC

摘要:

86 THE ANALYSIS OF PLASTICS FORMULATIONS [PYOC. SOC. Amalyt. Chezut. The Analysis of Plastics Formulations The following are summaries of two of the papers presented at a Meeting of the East Anglia Section held on February 19th 1969 and reported in the March issue of Proceedzhgs (Pa 34) The Impact of Physical Sciences on Polymers and Copolymers of Styrene BY T. B. GAY MODERN polystyrene formulations are a complex mixture of ingredients especially selected to produce a particular set of desirable and saleable qualities. As developments in both polymer technology and analytical methods are involved a general account of the development of styrene polymers is presented and relevant analytical methods discussed when necessary. The physical properties of these polymers were discussed briefly and the studies of the micromorphology of mixed-phase systems by m j c r o ~ c o p i c ~ ~ ~ ~ ~ $ ~ and electron microscopic5 examination were mentioned.The determination of chemical composition was discussed in detail and the following points were considered. (i) A brief history of the identification of styrene,6 its polymerisation its commercial manufacture’$* and its analysis.9 (ii) Standard polystyrene its pi-operties,1° molecular weight and molecular-weight distribution measurements,11J2 ultraviolet and gas - liquid ~hromatographicl~J~1~~ measure- ments of residual monomer and identification and determination of p1a~ticisers.l~~~~ (Reseavch Depavtment Monsanto Chemicals Ltd. Newpovt Mom.) May 19691 THE ANALYSIS OF PLASTICS FORMULATIONS 87 (iii) Impact and solvent resistant polystyrenes composed of rubber-toughened poly- styrenes styrene - acrylonitrile copolymers and finally acrylonitrile - butadiene - styrene formulations.Measurement of the rubber and acrylonitrile contents by spectroscopic,ls conventional chemical and pyrolysis - gas chromatographic approaches were described. (iv) Light-stabilised and antistatic formulations were discussed and ultraviolet infrared and gas-chr~matographic~~J~ approaches were briefly mentioned. (v) Odour and taint considerations were compared from results obtained by Odour and Taint Panels and gas-chromatographic investigations. In this instance gas-chromatographic methods of sensitivity greater than that of the Test panels have been developed which have enabled standard procedures for odour and taint testing to be adopted.Interesting correla- tions have been established and work is continuing in this area. (vi) Thermal analysis20,21 of polymers and additives was illustrated and valuable contribu- tions to understanding basic processes may develop from such investigations. (vii) Expanded polystyrene was considered and information obtained from gas-chromato- graphic investigations of pneumatogen and residual monomer and thermal analyses illustrate methods of obtaining important parameters on the fundamental properties of pre-foaming and pre-foam collapse. In conclusion other physical and analytical methods vital to the understanding of the over-all chemical nature of a polymer formulation and the breakdown into its constituents were mentioned. The size distribution and physical arrangement in mixes have a critical effect on the properties of the final product its environmental behaviour and its subsequent use.To emphasise this the over-all chemical composition of modern polymers although essential is but a starting point in their characterisation. Alone it can furnish only a limited amount of information on their final performance in finished articles. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. REFERENCES Merz. E. H. Baer M. and Claver G. C. J . Polyw. Sci. 1956 22 325. Merz. E. H. and Claver G. C. Off. Dig. Fed. Paint Vavn. Prod. Clubs 1956 28 858. Claver G. C. Spec. Tech. Publs Awer. Soc. Test Matev. 1963 No. 348. Fletcher K. Haward K. N. and Mann J. Chevn. 6 Ind. 1965 1854. Keskkula H. and Traylor P. A. J . AppZ. Polyw. Sci. 1967 11 2361.Simon E. Justus Liebigs A n n l n Chevn. 1839 31 265. Hornibrook J. N. Chem. & Ind. 1962 872. Sully B. D. Ibid. 1967 540 and 871. Hollis 0. L. Analyt. Chew. 1961 33 352. Teach W. C. and Keissling G. C. “Polystyrene,” Reinhold Publishing Corp. 1960. Baker C. A. and Williams R. J . P. J . Chew. Soc. 1956 2352. Moore J . C. J . Polyun. Sci. 1964 2A 835. Shapras I?. and Claver G. C. Analyt. Chew. 1964 36 2282. Crompton T. R. Myers L. W. and Blair D. Bvit. Plast. 1965 38 740. Crompton T. R. and Myers L. W. Eur. Polyw. J. 1968 4 355. Wandel M. and Tengler H. Kumistofle 1965 55 655. Jankowski S. J. and Garner P. Analyt. Chem. 1965 37 1709. Dinsmore H. L. and Smith D. C. Ibid. 1948 20 11. Davies J . T. and Denham B. H. Analyst 1968 93 336. Wendlandt W. W. “Thermal Methods of Analysis,” Interscience Publishers New York 1964.Slade P. E. and Jenkins L. T. “Techniques and Methods of Polymer Evaluation. Volume 1. Thermal Analysis,” Edward Arnold London 1966. The Determination of Certain Additives in Polythene and Polystyrene BY J. T. DAVIES (Reseavch and Development Depavtment T h e Metal Box Company Limited Acton London W.3.) TWO classes of additive incorporated into packaging-grade polythenes are antistatic agents and slip agents. Antistatic agents reduce any static charge on the package surface which in turn reduces dust pick-up. Two common classes of antistatics are the alkyl diethanolamines and alkyl diethanolamides. For analysis these were extracted from the polythene with chloroform by using a Soxhlet flask. The chloroform extracts were evaporated to low bulk and some of the low molecular-weight polythene precipitated by the addition of methanol.Both classes of additives were then gas chromatographed as their trimethyl silyl ethers. On- column injection was needed to get the best results. The columns were packed with 5 per 88 ANALYSIS OF FOOD FLAVOURS [PYOC. SOC. AutaZyyt. Cheuut. cent. E301 on Chromosorb W and were used isothermally at temperatures up to 250°C. Separation was obtained between the homologues present in commercial samples of both the diethanolamides and diethanolamines. The partial decomposition of the diethanolamides during heating was described. Slip agents which are added to film-grade polythenes are usually the amides of oleic or erucic acids. These compounds were extracted from polythene with chloroform and gas chromatographed directly on columns packed with 2 per cent.Versamid 900 on Chromosorb W. This was caused by the presence of a homologous series of hydrocarbons i.e. the low molecular-weight polymer. The various additives mentioned so far could all be examined qualitatively by using thin-layer chromatography. Polystyrene of the toughened grades contains several non-polymeric compounds including the non-volatile additives such as lubricants antioxidants antistatic agents and pigments and smaller amounts of more volatile compounds such as styrene monomer. Some simple experiments were described in which volatile compounds released from polymers during storage in closed containers were investigated. Chromatograms of the volatiles from experimental grades of polythene and polystyrene were shown as examples. The difficulty of analysing extracts of high density polythene was stressed.

ISSN:0037-9697    

DOI:10.1039/SA9690600086

出版商:RSC    

年代:1969

数据来源: RSC

摘要:

88 ANALYSIS OF FOOD FLAVOURS [PYOC. soc. AutaZyyt. Cheuut. Analysis of Food Flavours The following is a summary of the paper presented at a Meeting of the North of England Section held on February 22nd 1969 and reported in the March issue of Proceedivzgs (p. 33). The Application of Newer Techniques to the Analysis of Food Flavours BY D. A. WEYL ( Unilevev Reseavch Labovatovy Colwovth House Shavnbvook Bedfovdshive) THE present procedures in the analysis of food flavours were outlined under the headings Extraction Concentration Separation of flavour components and Attempts being made to identify those components. Although it is not always necessary to extract a food flavour it is usual to resort to solvent extraction maceration processes or headspace sampling techniques and with spices and perfumery materials steam distillation is also used.The methods of concentrating the sample depend on the method of extraction. Thus volatile solvent is removed by rotary evaporation. When coconut oil has been used in a maceration process the extracted flavours can be removed by vacuum de-gassing. Zone- refining techniques were also favoured at Colworth House although the solvent benzene for this purpose itself needed to be purified by zone-refining methods because the method tended to bring all the impurities in the original benzene into the same fraction which finally con- tained the flavourings. By this method lOOkg of raspberries could be expected to yield about 4 g of concentrated flavour consisting of a 30 per cent. solution of raspberry volatiles in benzene. The advantage of the method is that it preserves the fresh raspberry flavour and does not produce a cooked flavour.The separation of the flavouring component? has been attempted in a number of different ways. Extremely efficient distillation has been used for example spinning band columns. Chemical separation into broad bands is also possible. Chromatographic methods are extremely important. Liquid - solid chromatography with gradient elution has proved valuable for broad separations gas - liquid chromatography currently gives the best resolu- tion of the components of an aroma complex but thermal dissociation is a considerable problem. Thin-layer chromatography is often used as for example in the investigation of “off” flavours in oils andfats which are thought to arise from a seriesof unsaturated aldehydes.The method separates in terms of molecular weight and in terms of unsaturation but it tends to be insensitive to positional differences in the double bonds and to the stereochemistry of the molecule. This insensitivity can be overcome by such methods as impregnating the plates with silver nitrate. The silver forms weak complexes with ethylenic double bonds, May 19691 MEMBERSHIP CHANGES 89 such complex formation being sensitive to the stereochemistry of the molecules and the position of the double bonds. A newly developed method of thin-layer chromatography involves the use of extremely thin glass fibres coated with active material. These are spotted and eluted in the usual way and when the solvent has been evaporated the fibre is mounted horizontally and examined by means of a flame-ionisation detector.The most recent development is liquid - liquid chromatography which is similar to gas - liquid chromatography except that the mobile phase is a liquid one such as heptane which contains a moderator e.g. isopropyl alcohol to modify the surface of the silicic acid and hence its polarity retention characteristics. Low isopropyl alcohol concentrations can be used and intermediate stationary-phase moderated characteristics are obtained by using a narrow range of temperatures. As the method is intended for use at lower temperatures than those used for gas - liquid chromatography it is very suitable for flavour analysis. A popular method has been based on retention times or more precisely by means of the Kovats Index by which the position of a flavour peak is related to that of two standard alkanes.Unfortunately a Kovats Index of say 1180 & 5 could encompass many different materials typically a dozen or more. Mass spectroscopy has become one of the most common identification techniques used in flavour chemistry as it can be linked to the gas - liquid chromatographic effluent. In practice when using packed gas - liquid chromatographic columns the effluent is first put through a concentrator such as the Biemann concentrator which allows the helium purging gas to pass through a porous glass tube but retains the organic effluent. Attempts to link a spectrograph with gas - liquid chromatographic effluent have met with partial success but trapping methods are at present much more common. trapped on a tube filled with gas - liquid chromatographic absorbant packing (e.g.Apiezon L on Celite) are heated while argon purging gas is passed through them and the effluent con- densed in a small collecting tube at liquid nitrogen temperature. This can be washed with carbon tetrachloride and centrifuged for sampling with a micro syringe. For higher boiling materials condensation of flavouring material from traps directly on to potassium bromide powder and subsequent cold pressing have been used. Infrared spectra on amounts of about 10 pg and in some instances 1 or 2 pg have been obtained. Nuclear magnetic resonance suffers the disadvantage of requiring relatively large samples but sometimes it is the best method by which isomers may be identified. One of the major problems of flavour chemistry is that the sensitivity of instruments is still far behind that of the nose and mouth.Some attempts to use insect odour receptors as gas - liquid chromatographic detectors have been reported but these are usually too specific for general flavour chemistry. At all stages in the extraction and separation it is necessary to check the odours organoleptically during gas - liquid chromatographic separation usually by such means as splitting the effluent from the gas - liquid chromatography partly through a flame-ionisation detector and partly into a smelling port. Often odours occur where no peaks appear. The use of the work described may eventually be to synthesise flavourings or to find which components of a flavour may be lost during processing so that perhaps something can be done to improve flavour characteristics by returning lost components.The investiga- tion of “off” flavours often leads to an understanding of the steps necessary to prevent this kind of deterioration. Once the separations have been made identification is attempted. Infrared spectrometry is the traditional method of investigating flavours. Materials which have been Changes in the Register of Members NEW MEMBERS ORDINARY MEMBERS Dennis John Bucknell A.R.I.C. ; Michael William George Burt; Ronald James Clark; Francis Richard Daubney ; Brian Robert Farrant; Barry John Anthony Goodman B.Sc. (Durham) ; George Francis Hodsman B.Sc. Ph.D.(Leeds) F.1nst.P. ; Christopher James Miller; David Keith Newby B.Sc.(Bristol) ; Norman Alfred Parris A.R.I.C. ; Michael Alan Pinnegar A.R.I.C. ; Antony John Thorp B.Sc.(Leeds) ; Roger John Whiteoak B.Sc. Ph.D. (Birmingham) ; Walter Bruce Yeoman B.Sc.(Lond.) A.R.I.C. M.C.Path. 90 PAPERS ACCEPTED FOR THE ANALYST [Proc. SOC. Analyt. Chem. STUDENT MEMBERS Is-Haq Fayeq Al-Ansari B.Sc. (Cairo) ; Richard Frederick Browner B.Sc. (Lond.) ; Heather Anne Fulton B.Sc.(Rand) M.Sc.(South Africa) ; Mohammad Rafi Fariduddin Khan BSc. (Poona) ; Terence Humphrey Risby L.R.I.C. ; Shirley Janet Wilson B.Sc. (Sheffield).

ISSN:0037-9697    

DOI:10.1039/SA9690600088

出版商:RSC    

年代:1969

数据来源: RSC

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90 PAPERS ACCEPTED FOR THE ANALYST [Proc. SOC. Analyt. Chem. Papers Accepted for Publication in The Andyst THE following papers have been accepted for publication in The Analyst and are expected to appear in the near future. “The Spectrophotometric Determination of Riboflavine in Urine,’’ by Nagi Wahba. “Construction of an Impedance Adaptor for Coupling the Perkin-Elmer Model 303 Atomic-absorption Spectrophotometer to a Recording System,” by W. D. Rasson and I. C. Hemingway. “The Analysis of Mixtures of Methyl Ethanesulphonate and Ethyl Methanesphonate by a Differential Reaction Rate Method,” by A. J. W. Brook and K. C. Munday. “A Simple Trace Reader with Digital Print-out,’’ by J. B. Dawson K. Milner and D. Mawston. “Automated Distillation Procedure for the Determination of Nitrogen,” by J .Keay and P. M. A. Menage. “Quantitative Analysis of Alkylphenol Isomers by Fluorine Magnetic Resonance Spectro- scopy,” by Kazuo Konishi Yoshihiro Mori and Norio Taniguchi. “The Atomic-emission Spectroscopy of the Rare Earth Elements in a Separated Nitrous Oxide - Acetylene Flame,” by D. N. Hingle G. F. Kirkbright and T. S. West. “The Determination of Silicon in Intact Steel Samples with a Low-output Neutron Generator,” by T. R. Pierce and K. Haines. “The Influence of Light on Silver - Silver Chloride Electrodes,” by G. J. Moody R. B. Oke and J. D. R. Thomas. “Identification of Polyalcohols on Thin-Layer Chromatograms with 2-Thiobarbituric Acid,” by M. A. Nisbet. “Determination of Thallium in Biological Material by Flame-spectrophotometric Methods,” by A. S. Curry J. F. Read and A.R. Knott. “The Detection of Prophylactic Drugs in Animal Feeding Stuffs by Thin-layer Chromato- graphy,” by P. W. Hammond and R. E. Weston. “Voltammetric Studies with Different Electrode Systems. Part IV. Determination of Silver with the Silver - Molybdenum System,” by V. T. Athavale M. R. Dhaneshwar and R. G. Dhaneshwar. “Some Observations on the Analytical Utility of Electrochemiluminescence for the Determination of Trace Amounts of Aromatic Hydrocarbons,” by B. Fleet P. N. Keliher G. F. Kirkbright and C. J. Pickford. “Nitrate Determination of Soil Extracts with the Nitrate Electrode,” by A. 0ien and A. R. Selmer-Olsen. “The Gas-chromatographic Determination of 2-Chloro-4-nitrobenzamideJ 3,5-Dinitro- benzaniide and 3,5-Dinitro-o-toluamide in Animal Feeding Stuffs,’’ by R. A.Hood- less and R. E. Weston. “Milligram Determination of Thiourea and Some of its Derivatives with N-Bromo- succinimide,” by R. D. Tiwari and U. C. Pande. “Evaluation of Esterases from Livers of Beef Pig Sheep Monkey and Chicken for Detection of Some Pesticides by Thin-layer Chromatographic Enzyme Inhibition Technique,” by C. E. Mendoza D. L. Grant B. Rraceland and K. A. McCully. “The Determination of Aliphatic Aldehydes via Polarography of their Girard T Deriva- tives,” by B. Fleet and P. N. Keliher. May 19691 PUBLICATIONS RECEIVED 91 “Radio-release Determination of Fluoride Ion,” by I. A. Carmichael and J. E. Whitley. “The Determination of Inorganic Iodide in Urine by Neutron-activation Analysis ” by D. 5. Morgan A. Black and G. R. Mitchell. “An Indirect Amplification Procedure for the Determination of Titanium by Atomic- absorption Spectroscopy,” by G. F. Kirkbright A. M. Smith T. s. West and R. Wood. “Low Temperature Fluorescence of Some Bromide-ion Association Complexes in Hydro- bromic Acid Glasses at -196”C,” by G. F. Kirkbright C. G. Saw and T. S. West. “A Test for Cyclotrimethylenetrinitramine,” by S. A. H. Amas and H. J. Yallop.

ISSN:0037-9697    

DOI:10.1039/SA9690600090

出版商:RSC    

年代:1969

数据来源: RSC

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May 19691 PUBLICATIONS RECEIVED 91 Publications Received The publications listed below have been received by the Editor of The Afialyst in which journal Rook Reviews will continue to appear. RAKETENTREIBSTOFFE. Pp. xviii + 805. Wien and New York Springcr-Verlag. 1968. Price $85. N.B.S. TECHXICAL NOTE 467. PART 1. ACTIVATION ANALYSIS A BIBLIOGRAPHY. PART 2. APPENDICES. Edited by G. J. LUTZ €2. J. BORENI K. S. MADUOCK and W. W. MEINKE. Pp. xii + 511 (Part 1) and iv + 203 (Part 2) Washington D.C. U.S. Department of Com- merce. 1968. Price $6.50 (for the two parts). ION EXCHANGE. VOLUME 2. Edited by JACOH A. MARINSKY. Pp. vi + 250. New York Marcel Dekker Inc. 1969. Price $12.75. REFLEXIONSSPEKTROSKOPIE. GRUNDLAGEN METHODIK ANWENDUNGEN. By G. KORTUM. Pp. viii + 378. Berlin Heidelberg and New York Springer-Verlag.1969. Price $21.50. DEVELOPMENT OF THE CHEMICAL BALANCE. By JOHN T. STOCK. Pp. vi + 50. London H.M. Stationery Office. 1969. Price 10s. SYMPOSIUM ON OKGANOMETALLIC CHEMISTRY. Pp. vi + 179-272. London Butterworth R Co. (Publishers) Ltd. 1969. Price 40s. The contents of this hook appeav in Pure and Applied Chemistry 1968 Vol. 17. CONFEKENCE. Y p . vi + 194. London Butterworth & Co. (Publishers) Ltd. 1969. Price 50s. The contents of this hook appear in Pure and Applied Chemistry 1968 Vol. 17. INTRODUCTION TO QUANTUM CHEMISTRY. By JAY MARTIN ANDERSON. Pp. xiv + 445. New York and Amsterdam W. A. Benjamin Inc. ORGANIC MAGNETIC RESONANCE. An International Journal. Edited by ERIC F. MOONEY. Volume 1. Issue 1. With Spectral Supplement 1/1. Pp. 92. London Heyden & Son Ltd.1969. By ARMIN DADIEU KALF DAMN and ECKART W. SCHMIDT. ORGANOMETALLIC CHEMISTRY-PLENARY I’ECTURES PRESENTED AT THE THIRD INTERNATIONAL CO-ORnINATION CHEMISTRY-PLENARY LECTURES PKESENTEL) AT THE TENTH INTERNATIONAL 1969. Subscription Price Ll6 10s. Od. A New Jownal ANALYTICAL CHEMISTRY OF Low CONCENTRATIONS. By I . M. KOREMAN. Translated from Russian by J. SCHMORAK. Jerusalem Israel Program for Scientific Trans- lations. Distributed by H. A. Humphrey Ltd. London. 1968. Price 63s. MOSSRAUER EFFECT METHODOLOGY. VOLUME 4. Edited by IRWIN J. GRUVERMAN. Pp. viii + 270. New York Plenum Press. 1968. L15. THE DETERMINATION OF EPOXIDE GROUPS. MONOGRAPHS IN ORGANIC FUNCTIONAL GROUP ANALYSIS. VOLUME 1. Edited by 13. DOBINSON B.Sc. Ph.D. W. HOFFMANN D.Phil. and B. P. STARK M.A. Ph.D.Oxford London Edinburgh New York Toronto Sydney Paris and Hraunschweig Pergamon Press. COMPUTER PROGRAMS FOR CHEMISTKY. VOLUME 1. Edited by DELOS F. DETAR. Pp. xx + 208 New York and Amsterdam W. A. Benjamin Inc. 1968. Price $14.75. Pp. vii + 118. Pp. viii + 79. 1969. Price 42s. ; 966. 92 NOTICES [PYOC. SOC. Analyt. Chevtz. ABSORPTION SPECTROPHOTOMETRY. By G. F. LOTHIAN M.A. F.1nst.P. Third Edition. Pp. viii + 246. London Adam Hilger Ltd. 1969. Price 60s. MATERIAL. BERLE M.Sc. Pp. xxii + 870. London The Pharmaceutical Press. 1969. Price j514. Butterworth & Co. (Publishers) Ltd. 1969. Price 100s. London Butterworth & Co. (Publishers) Ltd. 1969. Price LlO. ISOLATION AND IDENTIFICATION OF DRUGS I N PHARMACEUTICALS BODY F L U I D S AND POST-MORTEM Edited by E. G. C. CLARKE M.A. Ph.D. D.Sc. F.R.I.C. Assisted by JUDITH ELECTRODE REACTIONS OF ORGANIC COMPOUNDS (Faraday Discussion No. 45). Pp. 282. London SYMPOSIUM ON FIBROUS PROTEINS. AUSTRALIA 1967. Edited by W. G. CREWTHEK. Yp. 432.

ISSN:0037-9697    

DOI:10.1039/SA9690600091

出版商:RSC    

年代:1969

数据来源: RSC