摘要:

ANALYST, AUGUST 1986, VOL. 111 993 CO M M U N ICATlO N Material for publication as a Communication must be on an urgent matter and be of obvious scientific importance. Rapidity of publication is enhanced if diagrams are omitted, but tables and formulae can be included. Communications should not be simple claims for priority: this facility for rapid publication is intended for brief descriptions of work that has progressed to a stage at which it is likely to be valuable to workers faced with similar problems. A fuller paper may be offered subsequently, if justified by later work. Manuscripts are usually examined by one referee and inclusion of a Communication is at the Editor‘s discretion. Method for the Determination of the Marker and Dye in Heavy Fuel Oils Elsie M. May, David C.Hunt and David G. Holcombe laboratory of the Government Chemist, Cornwall House, Waterloo Road, London SEI 8XY, UK Keywords: Reversed-phase high-performance liquid chromatography; gas oil; DERV; marker additive; dye additive Heavy fuel oils are used in a number of industrial applications and as a road fuel. For the latter, the term DERV (diesel engine road vehicle) is applied and for all other applications the term gas oil is used. A substantially higher duty is payable for using heavy oil as a road fuel. Gas oil is therefore distinguished from DERV by the addition of a marker and dye to the former. It is an offence to use gas oil as a road fuel and Officers of Her Majesty’s Customs and Excise (HMCE) are empowered to sample both bulk supplies of road fuel and the fuel tanks of road vehicles.Apart from the illicit use of marked gas oil as a road vehicle fuel, gas oil may also be “laundered” by the removal of the marker and dye in an attempt to evade detection if the fuel should be sampled by HMCE. This work was directed towards the detection and quanti- tation of residual amounts of marker and dye found in laundered fuel. The proportion of marker and dye in gas oil is laid down under Statutory Instrument 1134 of 1981, namely that it shall contain 1.75 g of 1,4-dihydroxyanthraquinone (quinizarin) and 4 g of Solvent Red 24 per 1000 1 of gas oil (Fig. 1). In laundered gas oil these two compounds will be present in lesser amounts and the ratio of their concentrations may not match that specified in law. The analytical method is based on the separation of the various constituents by liquid chromato- graphy and detection by ultraviolet (UV) absorption.Three stages are involved, as follows: (i) A concentration step, in which the marker and dye are separated from the bulk of the gas oil by retention on a silica cartridge, which is then washed with hexane to remove the hydrocarbons. The hexane-insoluble fractions of gas oil, which include asphaltenes and polynuclear hydrocarbons, are also retained. (ii) A “clean-up” step in which the marker and dye are separated from the hexane-insoluble compounds by column chromatography using silica. (iii) Finally, quantitation of the marker and dye is achieved by injecting the concentrated eluate from the silica column on to a high-performance liquid chromatographic (HPLC) reversed-phase column.Experimental Reagents of silica gel. Hexane. HPLC grade. Dried by passage through a column Acetonitrile. HPLC grade. Ammonium formate. Analytical-reagent grade. Amy1 alcohol. Stored over anhydrous sodium sulphate. Silica cartridges. Waters Sep-Pak. Glass chromatographic column. 200 x 10 mm i.d. Silica Kieselgel 60. Merck, 60-200 Fm (70-230 mesh ASTM), 5 g per column, prepared as a slurry in dry hexane. HPLC System Pump. Waters Model 6000A. Column. 200 x 4.6 mm i.d., 5 pm ODS Hypersil. Mobilephase. Acetonitrile - ammonium formate (90 + lo), adjusted to pH 7.6 with 0.1 M ammonia solution. 0 OH ij OH Quinizarin Me Me HO Solvent red 24 Crown Copyright. Fig. 1. Structures of gas oil marker (quinizarin; 1,4- dihydroxyanthraquinone) and gas oil dye (Solvent Red 24)994 ANALYST, AUGUST 1986, VOL.111 II 8 0 Q R A Fig. 2. Thin-layer chromatogram showing separation of marker and dye from other constituents of gas oil after partial clean-up. Q = Quinizarin; R = Solvent Red 24; A = extract from unmarked DERV 0 2 4 6 8 10 T i r n e h i n Fig. 3. Chromatogram (HPLC) of unmarked DERV following clean-up procedure Injection. Rheodyne Model 7125 valve, 200-pl loop. Flow-rate. 3.0 ml min-1 at 2000 lb in-2. Detector. Beckman 165 dual-channel UV detector set at 260 nm and 485 nm at 0.05 a.u.f.s. The marker and dye have maximum responses at 485 and 520 nm, respectively. The detector signal was integrated at 485 nm in order to maximise the response for the marker, this being the minor component.The other detector channel was set at 260 nm to monitor any residual asphaltenes and polynuclear hydrocarbons. Preparation and Clean-up of the Gas Oil Sample Preliminary studies using thin-layer chromatography (TLC) showed that the marker and dye, together with the natural polyaromatic hydrocarbons in gas oil, adsorb strongly on silica and can be eluted with methanol, but not with hexane. Thus, adsorption on a silica cartridge, washing with hexane and subsequently eluting with methanol provides a means of concentrating the marker and dye and removing the gas oil hydrocarbons. HPLC of this eluent showed that the concen- trated polynuclear hydrocarbons co-eluted with and therefore masked the dye and marker at 485 nm. A further clean-up was therefore necessary and was achieved by using dry hexane containing 0.05% of amyl alcohol.On TLC this mobile phase effects a partial separation between the interfering poly- nuclear hydrocarbons and the marker and dye, which elute together (Fig. 2). Transferring this TLC system to a silica- packed glass column and collecting the marker/dye band eliminated a large proportion of the interference. The method finally adopted was as follows. Using a gas-tight syringe attached to the silica cartridge, 10 ml of gas r" t v) c 0 n al u I I a 0 2 4 0 2 4 6 8 1 0 1 2 1 4 Ti rn e/rn i n Fig. 4. Chromatogram (HPLC) of standard solution of marker and dye. (a) Quinzarin; and (b) Solvent Red Table 1. Quantitative examination of laundered gas oil Concentration of marker/ g per 1000 1 A .. . . . . 0.24 B . . . . . . 0.78 C . . . . . . 0.03 D . . . . . . 0.08 E . . . . . . 0.27 F . . . . . . 0.25 Concentration of dye/ g per 1000 1 0.45 1.05 0.31 0.67 0.93 1.65 Ratio of marker to dye 0.53 0.74 0.10 0.12 0.29 0.15 oil were forced through the cartridge. The issuing oil was colourless. The cartridge was then washed with successive portions of dry hexane (totalling 100 ml) to remove the gas oil hydrocarbons. The cartridge was emptied and the silica allowed to dry in the air. It was placed on the top of the glass column containing silica, tamped down to an even layer and covered with a plug of glass-wool. The adsorbed material was eluted with the hexane - amyl alcohol at 5 ml min-1. Slight suction with a water pump was necessary. The breakthrough volume of the markeddye band was approximately 230 ml.The volume of 60 ml containing the markeddye fraction was collected, evaporated to dryness and redissolved in methanol (1-10 ml, depending on the expected concentration of the marker). An aliquot (200 pl) of this solution was injected on to the HPLC column. Results and Discussion Recovery Experiments Unmarked DERV was subjected to the above process several times to confirm that asphaltenes and polynuclear hydrocar- bons were effectively removed, so as not to interfere with the HPLC system (Fig. 3). Chromatograms of standard solutions of marker (2 mg 1-1) and dye (4 mg 1-1) in methanol are shown in Fig 4. It will be noted that the dye, being an industrial-grade chemical, contains several isomers, whose concentrations were summed to determine the total dye content.The coefficients of variation of six replicate analyses were 0.5% for the marker and 0.9% for the dye. Known amounts of the marker and dye, in the range encountered in laundered material, were added to DERV to determine the efficiency of recovery. Six replicate determinations gave values of 65-80% for the marker and 89-96% for the dye.ANALYST, AUGUST 1986, VOL. 111 995 t al C 0 n. v) U CI b 0 2 4 6 8 1 0 Ti me/m i n Fig. 5. Chromatogram (HPLC) of laundered gas oil Detection Limit The detection limit is 0.2 mg 1-1 for the marker and 0.4 mg 1-1 for the dye in the final solution. This represents 0.02 and 0.04 g per 1000 1 of gas oil, respectively, i.e., two orders of magnitude less than the concentrations encountered in unlaundered oil. Linearity Linearity of the detector response was established over the range of interest, namely 0.5-10 mg 1-1 of injected solution. Samples of Suspected Oil A number of samples of suspected laundered gas oil were examined on behalf of HMCE. Absolute levels of the marker and dye were found to be significantly less than the legal requirement (Table 1). A distinction can be made between laundered gas oil and DERV diluted with oil on the basis of the changed ratios of the two additives. Fig. 5 shows a laundered gas oil in which the marker and dye are present at 0.78 and 1.05 g per 1000 1, respectively. The ratio of marker to dye is 0.74 compared with a value of 0.44 to accord with the Statutory Instrument, Paper A61159 Received May 22nd, 1986

ISSN:0003-2654    

DOI:10.1039/AN9861100993

出版商:RSC    

年代:1986

数据来源: RSC

摘要:

ANALYST, AUGUST 1986, VOL. 111 997 SOFTWARE REVIEW From time to time, The Analyst will publish reviews of computer software packages designed for analytical applications. Commercial and other suppliers of such packages are invited to submit analytical software for review; full technical specifications should be included. CLEOPATRA-Chemometrics Library: An Extendable Set of Programs as an Aid in Teaching, Research and Application. G. Kateman, P. F. A. van der Wiel, T. A. H. M. Janse and B. G. M. Vandeginste. Elsevier Scientific Software. 1985. Price $820; f555; Df12220 (IBM-PC); $735; f495, Df11980 [Hewlett-Packard 9845-B(T)J. Manual only $42.50; €29; Dfl115. Technical specifications: Computer: Operating system: Language: Required pe ri p hera I s: Required extension: Minimum memory: Storage medium: Order Ref.No.: Computer: Language: Minimum memory: Order Ref. No.: IBM-PC (3 diskettes and manual) PC-BASIC. Both an interpreter ver- sion and a compiled version are provided 360K 5&in diskette drive, hard disk (optional), printer (optional) Co I o u r/g rap h i cs ad a pto r 128K RAM Diskettes, 5$-in, dou ble-sided, double density ISBN 0 444 42413 X PC-DOS 2.0 Hew I ett- Pac ka rd 9845- B (T) HP-BASIC 186K RAM 0 444 42325 7 Chemometrics, a synthesis of chemistry and mathematics, has done much in recent years to change both the look and the philosophy of chemistry. In the laboratory, data collection and management tasks have been largely turned over to the computer, giving the laboratory more than just a new appearance by increasing the productivity of these everyday operations.Computer-intensive methods are also changing fundamental philosophies of instrument design, resulting in instruments that are simpler, more rugged and more reliable. In many instances, complex physical processes are being modelled, better understood and even replaced by relatively simple mathematical procedures. This, in turn, permits more information to be obtained from a given set of data. Further aspects of chemistry are certain to feel the impact of chemometrics in the future. This knowledge was not wasted by the authors of CLEO- PATRA, who have assembled a software package to allow chemists and other scientists to explore several facets of chemometrics. Version 1 .O of CLEOPATRA contains six modules (sampling of correlated lots; monitoring of processes; process reconstruction: autocorrelation and autoregression; curve fitting; and fast Fourier filtering) that can be applied in a wide variety of disciplines, not simply in chemistry.Any endeavour in which sampling and measurement are important considerations can potentially benefit from the techniques uncovered in CLEOPATRA. CLEOPATRA runs on the IBM-PC microcomputer and is supplied on three DSDD 5.25-in floppy diskettes together with a complete manual. It requires at least 128K RAM and one 360K diskette drive. The colour/graphics adapter is also a necessity, although the program does not make use of colour. CLEOPATRA is written in PC-BASIC under PC-DOS 2.0, and is supplied in both interpreter and compiled versions.IBM-PC compatible microcomputers should be able to run CLEO- PATRA provided that they are equipped as described above. The manual states that “most versions of the GW-BASIC interpreter suffice” when running the interpreter version of CLEOPATRA, but that “the BASICA interpreter is preferred . ” CLEOPATRA is also available for the Hewlett-Packard 9845B(T) computer. This HP-BASIC version requires at least 186K RAM, the GRAPHICS ROM (including hardware) and the IIO ROM. CLEOPATRA has a well designed modular, menu-driven structure. The system is easily generated using the directions given in the manual. A program run begins with a module selected from a menu, and control returns to the menu on termination of the module’s execution. The graphics prepared by the modules are informative and succinct, and the input-error trapping facilities work well.Defaults are pro- vided for all input values, effectively giving examples of the operation of each module to supplement the instructions. The manual describes the internal menu structure, the variables passed and the files required by the system fairly well, so that users can extend the system with their own modules (and also with future releases from Elsevier). Paradigm files are provided for users who wish to add their own modules to the system. The manual gives a good overview of the CLEOPATRA system and a brief introduction to the theory behind the operation of each module. Users are cautioned, however, to refer to a textbook for a complete description of the theoretical background behind each module.Overall, the manual is well edited and contains few errors (mostly trivial in nature; for instance, asking users to supply a 13-character label during system generation, when only 11 characters are allowed). CLEOPATRA is obviously written to provide hands-on training in chemometrics. Researchers who desire to use it in the laboratory should have some experience in microcomputer programming, because the system (particu- larly the input and output portion) will have to be modified in order to interact effectively in a research environment. Finally, while the modules dealing with sampling and measurement are very well done, chemometrics has many other aspects, such as optimisation, pattern recognition and modelling, that are not addressed (as least as yet) by CLEOPATRA. A comprehensive training system should include a more thorough representation of the field. Many organisations may have difficulty justifying expenditure for software that is narrow in scope, regardless of how well the contents of that limited scope are treated. R. Lodder G. M . Hieftje

ISSN:0003-2654    

DOI:10.1039/AN9861100997

出版商:RSC    

年代:1986

数据来源: RSC

摘要:

998 ANALYST, AUGUST 1986, VOL. 111 BOOK REVIEWS Applications of Circularly Polarized Radiation Using Synchrotron and Ordinary Sources Edited by Fritz Allen and Carlos Bustamante. Pp. xii + 193. Plenum Press. 1985. Price $45. ISBN 0 306 42087 2. High-energy light sources penetrating to shorter wavelengths than the conventional ultraviolet - visible wavelength region are extending the scope of analytical absorption spectroscopy. Where the title of this collection of conference papers refers to “ordinary sources,” then the topic under discussion is circular dichroism (CD) spectroscopy. Practitioners of this analytical technique will recognise the authors as established authorities in the field, who have provided valuable research results in important areas of nucleic acid, protein and polysaccharide spectroscopy as part of this volume.Theoretical aspects form a substantial part of the CD coverage, and also of the two other topic areas: “synchrotron radiation spectroscopy” and scat- tering of polarised light. An excellent survey is provided by U. Heinzmann of the possibilities of circularly polarised vacuum ultraviolet radiation in spectroscopic studies; in other words, synchrotron radiation in the 120-165 nm wavelength range. The remaining papers provide a fascinating insight into the interaction of some familiar optically active organic com- pounds with this non-routine radiation. Although the actual experimental work will continue to be the province of just a few people, the results have considerable significance in the theoretical support of photoelectron and more routine absorp- tion spectroscopic studies.The papers have been re-typed for direct reproduction, with a good uniform presentation but with the penalty of numerous typographical errors having been introduced. These do not obscure the scientific content but the valuable, up-to-date lists of references and numerical data may have errors buried in them which are not so easy to spot as the whimsical spelling of authors’ names that appears frequently. G. C. Barrett New Directions in Chemical Analysis. Proceedings of the Third Symposium of the Industry - University Coopera- tive Chemistry Program of the Department of Chemistry, Texas A & M University, March 31-April 3, 1985 Edited by Bernard L. Shapiro. Pp. xix + 502. Texas A & M University Press.1985. Price $45. ISBN 0 89096 255 3. This Symposium volume is a tribute to the organisers’ skills that the aimed for rapidity of publication has been achieved in an acceptable format and at a reasonable price. The volume illustrates the cardinal role of analytical chemistry in chemistry as a “central science” with contributions ranging from the characterisation of surfaces to separations, and from strategies for data measurement and interpretation to methodologies for elucidating the chemistry of the life process. Fifteen authors painted this broad picture in a venture designed to foster awareness and exchange of information among the sub- disciplines of analytical chemistry. In addition there are the abstracts of 20 poster presentations.The papers presenters and their titles are as follows: Ronald D. Macfarlane, “New Directions in Solid State Mass Spec- trometry: The Role of the Matrix in the Formation of Gas Phase Molecular Ions”; Colin A. Fyfe, “Investigation of the Structures of Highly Siliceous Zeolites by T i and 27Al MAS NMR Spectroscopy”; Robert L. Swofford, “Recent Advances in Laser-based Detection”; Georges Guiochon, “The Migra- tion of Finite Concentation Zones in Chromatographic Columns and the Optimisation of Preparative Liquid Chro- matography”; Alan G. Marshall, “Fourier Transform Methods in Spectroscopy”; A. T. Hubbard, “Electrochemical Surface Characterisation”; Albert C. Parr, “Synchrotron Radiation: Applications to Chemistry”; Jaromir RGiiCka, “Flow Injection Analysis: From Serial Assay to a New Concept of Measurement in the Chemical Laboratory”; James B.Callis, “Trends in Chemical Microsensors and Ultraminia- ture Chemical Instrumentation”; Nicholas Winograd, “Ion Beam Techniques”; Dudley H. Williams, “Mass Spectrometry and Nuclear Magnetic Resonance in Structure Determination of Bio-organic Molecules”; Milos Novotny , “Analytical Chro- matography: The Current Situation and Future Directions”; William P. Rothwell, “NMR Imaging: Nonmedical Applica- tions”; Jacob Schaefer, “Characterisation of Solid Polymers by Carbon-13 NMR”; and Tomas B. Hirschfeld, “New Directions in Chemical Analysis.” From the richness of this great cornocopeia of detailed review papers it is not easy to detect the new directions in chemical analysis, many of the micro-scale trends cancel out the over-all, macro-scale; thus trends are noted to micro-scale working in chemical sensors and certain instruments whereas for others, particularly NMR, bigger is clearly better, and synchrotrons are, if nothing else like most of the other goodies described in the book, expensive.If the over-all trends are not obvious, some single items that caught my attention include applications of NMR imaging to study diffusion into polymers, possibilities of using fibre-optic networks to monitor a large number of points throughout a factory, and some of the less obvious laser-based detection systems now becoming techni- cally feasible. D. Thorburn Burns Determination of Organic Substances in Water. Volume 1. T. R. Crompton. Pp. viii + 560.Wiley. 1985. Price €49.95. ISBN 0 471 90468 6. This book is the first of two volumes on the analysis of organic substances in water. Other materials, such as biota and sediments, associated with the water environment are also considered where appropriate. Volume 1 contains chapters covering hydrocarbons, detergents, pesticides and PCBs and herbicides. Volume 2 will cover other types of compound arranged by key elements, e.g., organometallics, nitrogen and sulphur, and will conclude with chapters on natural pigments and the organic compounds produced when using ozone as a potable water treatment chemical. The subjects of each chapter are dealt with very comprehen- sively and the whole analytical cycle, including sampling techniques, is covered. The literature has been researched very thoroughly up to 1980, with some references extending into 1981 and 1982.The chapters take the form of detailed literature surveys with discussion and in many areas descrip- tions of reagents and procedures. These are often given in a form which would enable them to be used to perform the analyses in the laboratory. The time taken to produce such a volume inevitably means that it will not include the latest techniques in detail. This is manifest in a lack of reference to capillary GC and HPLC. However, this does not detract from its usefulness and the techniques described and discussed are, in most instances, those in use at the present time. The book provides an excellent introduction for analysts new to the subject of organics in water and for those at present in the field who wish to extend their range of work.B. T. CrollANALYST, AUGUST 1986, VOL. 111 999 Method for the Determination of Low Concentations of Mercury in Fresh and Saline Waters S. Blake. Environment TR229, Pp. 28, Water Research Centre. 1985. Price f10. ISBN 0 902 156 17 9. This short (28-page) book describes a method for the determination of mercury in fresh and saline waters with a detection limit less than 2 ng I-’. It is one in a series of excellent publications produced by the Water Research Centre (WRc). The method, in a shortened form, would be suitable for publication as a paper in this journal. It utilises bromine oxidation to convert all forms of mercury in solution into ionic mercury. The excess of bromine is then destroyed using hydroxylammonium chloride and elemental mercury is generated in the conventional manner using tin(I1) chloride.The mercury vapour is then adsorbed on a gold mesh. After a 5-min collection period the gold mesh is rapidly heated and the desorbed mercury is carried in an argon stream to a conventional cold vapour absorption cell. There are a number of similar methods utilising pre-concentration on to gold mesh that have been published. Some of these are cited in the references. The book contains five sections: introduction; development of the method; results of performance tests; discussion; and conclusions. The Appendix -gives the final developed ana- lytical method with full performance characteristics, this being in the same format as the Standing Committee of Analysts “blue book” standard methods.This publication describes a relatively simple method that should be of interest to analysts who require to determine ultra-trace levels of mercury in fresh and saline waters. In the reviewer’s opinion the price (to non-WRc members) will tend to restrict sales. K. C. Thompson Jones‘ Instrument Technology. Volume 2. Measurement of Temperature and Chemical Composition. Fourth Ed it ion Edited by B. E. Noltingk. Pp. vi + 186. Butterworths. 1985. Price f16. ISBN 0 408 01232 3. The stated aim of “Instrument Technology” is to assist in the training of technicians who need to have some knowledge of instruments. The authors have attempted to tread a balanced path between expounding fundamental science and the description of trivial practical detail.This volume will be excellent for training or updating electrical - mechanical technicians working on process control or with laboratory- based equipment; it will be less useful to chemical based technicians unless they have a sound prior basis in electronics and mechanical concepts. The series contains four volumes, on “Mechanical Measure- ments,” “Electrical and Radiation Measurements,’’ “Instru- ment Systems” and that under review, namely “Measurement of Temperature and Chemical Composition.” The chapter on temperature measurement covers the vast range of available temperature sensors from direct effects (expansion of solids, liquids, gases, vapour pressure) to that on resistance, the thermoelectric effect and finally the radiation thermometer.In addition, the chapter includes discussion of the importance of the correct location of sensors within systems. The chapters on “Chemical Analysis” were produced by a team from the Central Electricity Research Laboratories. After a brief introduction the topics covered are spectroscopy, electrochemical techniques, gas analysis and moisture measurement. The material is mainly but not exclusively related to process control. The diagrams are particularly good, being more representative of real instruments or components than the usual outline schematics present in most undergrad- uate texts. Overall, a useful text; analytical chemists may find it refreshing to look at instruments from another viewpoint and their instrument technicians will appreciate having a text specifically written for them.D. Thorburn Burns Microcolumn Separations. Columns, Instrumentation and Ancillary Techniques Edited by M. V. Novotny and D. Ishii. Journal of Chromat- ograph y Library, Volume 30. Pp. xii + 336. Elsevier. 1985. Price $64.75; Dfl175. ISBN 0 444 42429 6. It is now well established that although micro-column liquid chromatography and associated analytical techniques can present operational problems, they do offer a number of advantages over their equivalent conventional procedures. Many of the recent developments in the field have originated in American and Japanese laboratories. In order to co- ordinate these efforts an informal exchange of ideas, manu- scripts and personnel between the laboratories of Milos Novotny and Daido Ishii, both well respected authorities, has been in existence since 1976.In 1982 a joint conference was arranged between the two countries in order to discuss advances in the field of micro-column separation methods and compatible ancillary techniques, and also to outline future potential directions. Although this volume is a direct result of this seminar, it is not a collection of the original presentations but rather an attempt by the co-Editors to provide a balanced treatment of the current situation in the field of micro-column separations. A total of 18 chapters are presented, divided into four sections. The first section covers column studies and includes open-tubular, packed capillary and size-exclusion micro- columns. Methods for the preparation of these columns are detailed together with some examples of the excellent separation efficiencies that can be achieved.The next section deals with miniaturised systems and specifically the critical importance of extra-column band broadening in micro- column techniques. Systems for fast analysis, capillary super- critical fluid chromatography and capillary zone electrophor- esis are also described. The third section covers spectroscopic detection, including optical, infrared, laser and flame detec- tors. The particularly interesting use of micro-columns with mass spectrometry receives coverage in two chapters, one specifically devoted to the various interfacing techniques. The final section on electrochemical detection covers ion chromat- ography, voltammetric and potentiometric detection.Although much of the information in this book could be obtained by a comprehensive literature search, it is useful to find it collected together in one volume. Many of the advances in the field of micro-column separations have been documen- ted by the very people who first reported them. Although a multi-authored book will always be somewhat variable in quality, the general standard in this volume is high, giving a very comprehensive and readable coverage of the field. Some chapters are prefaced by a short abstract, a very useful feature that was unfortunately not always adopted. A reasonable index is provided. The illustrations are always clear and of good quality. This book will provide a useful reference volumz for anyone interested in the subject uf micro-column separ- ations.C. R. Loscombe1000 ANALYST, AUGUST 1986, VOL. 111 Annual Reports on NMR Spectroscopy. Volume 16. Edited by G. A. Webb. Pp. x + 373. Academic Press. 1985. Price €91; $100. ISBN 0 12 505316 9. ISSN 0066 4103. lnstrumentelle Multi-element-analyse Edited by Bruno Sansoni. pp. xviii + 782. VCH. 1985. Price DM160. ISBN 3 527 26225 3. The first chapter of this volume by H. W. E. Rattle is entitled “NMR Studies of Amino Acids, Peptides and Proteins: A Brief Review, 1980-1982.” Its introductory section empha- sises the importance of modern techniques, mostly with simple or sophisticated pulse sequences and Fourier transformation. It is now almost routine to identify not only the amino acid constitutuents of the polymers but also the chain structure.Isotropic spin - spin coupling identifies pairs of adjacent residues while the anisotropic dipole - dipole coupling, which influences relaxation, can lead to accurate internuclear distances. In favourable instances full spatial arrangement, including dihedral angles, can be determined, especially if information from 13C, 2D and paramagnetic ion species augment the proton spectra. Appropriate NMR facilities are now essential for bio-organic chemistry. The 787 references are mostly from biochemical journals from 1980 to 1982 and demonstrate the rate of growth of this field. Chapter 2 on ll%n NMR parameters by B. Wrackmeyer tabulates this topic very fully. The relative convenience of l19Sn resonance with large chemical shifts, large spin - spin coupling and the absence of a quadrupole moment means that NMR is playing a major part in tin chemistry with its wide variety of compounds, many with more than one tin atom.The modern approach to both general and specific relax- ation processes that affect the NMR spectrum and its variation with temperature is perhaps less well known. The chapter on “Isomerisation Processes Involving N-X Bonds” by M. L. Martin, X. Y. Sun and G. J. Martin reminds readers of the widespread possibility of isomerisations, such as the N-N rotation in RIR2N-N=0. They use 556 references, mostly in the period 197G81, and 40 tables, which give typical coalescence temperatures, usually an activation energy, often AG$, AH$ and A S separately, for an exhaustive set of N-X-containing compounds.Finally, “Multiple Resonance” by W. McFarlane and D. S. Rycroft. This indicates the detailed schemes which are available both for homo- and heteronuclear problems. These are exemplified in a few instances, but the reader is able to find problems analagous to his own in the indications to the contents of 1058 references. In summary, a worthy successor to earlier volumes in the series although with the Editor and all authors from Europe the price in sterling looks excessively high in relation to the dollar price. Your reviewer is completing his reviews of this series and may be allowed to finish on a more personal note. In the autumn of 1946 he heard a lecture by Professor Purcell illustrated with an NMR line from paraffin wax several kilohertz wide because of magnet inhomogeneities.Besides the successful detection of signals he gave an accurate value of the proton gyromagnetic ratio and illustrated power saturation and TI measurement through the colourfully named “recovery time from the eating a hole in the curve effect.” No-one in the audience 40 years ago could have, in his wildest dreams, imagined the subsequent growth of NMR and its pervading influence on analysis in physics, chemistry, biochemistry, medicine and even archaeology. D. H. Whiffen This substantial book of over 700 pages is a collection of papers presented at the Symposium on Multi-element Instrumental Analysis held between April 2nd and 5th, 1984, in Jiilich. The Editor, Professor Sansoni, has brought together these papers under a number of headings including Nuclear Spectrometry, Activation Analysis, Mass Spectrometry, XRF, Atomic Spectroscopy, Voltammetry and Forward Scattering Measurements. The text covers a truly tremendous field and also devotes considerable attention to analytical methodology, including standards applications to geochemical analysis and archaeological determinations.Attention is also paid to hybrid techniques such as ICP - MS and also comparisons of various multi-element methods. In terms of the amount of analytical methodology and techniques involved, this must represent one of the most modern and wide-ranging compilations in recent times. The authors read like a list of Who’s Who in atomic spectroscopy and instrumental analysis in Europe, and many from the USA and UK. In this respect it is certainly a must for the analytical chemist who wants to be up to date with current developments and future trends in multi-element instrumental analysis.It must be said, however, that reading the book is certainly heavy going and would need to be a labour of love for many others who are not fluent in German, as approximately one-third of the papers are in that language. I think that is a pity, not because I do not think that English-speaking people should bother to learn German, indeed I regret the inability of most English-speaking scientists to communicate fluently in other European languages, but because it restricts the number of people who will read the full text of the book. Whilst recognising that it is an enormous task to translate technical texts, I would be very pleased to see in the future a second edition in which the German papers are translated into English for the benefit of the many people who do not have an adequate grasp of German. Fortunately, as with many scientific publications, there are sufficient tables and diagrams in the German text to permit reasonable understanding of the gist of the paper and many of the technical words permit approximate understanding without recourse to a dictionary. It would be wrong to dwell on that point as this is undoubtedly a very useful text which should find a place on the library shelves of universities and research institutions throughout the world. I particularly like the introductory paper by George Morrison on “Selected Opportunities in Analytical Chem- istry”, in which he appraises the role and success of the analytical chemist over the last two decades. Other papers of particular interest were the introductory one by Sansoni comparing and describing in general terms the various simultaneous multi-element analysis techniques, and charac- teristically excellent papers by Boumans et al., de Galan and a number of others. To sum up, this is a substantial and useful text of very high quality, nicely laid out and presented, which contains a vast amount of information; it is to be recommended to all practising and student analytical chemists. J . F. Alder

ISSN:0003-2654    

DOI:10.1039/AN9861100998

出版商:RSC    

年代:1986

数据来源: RSC