International symposium on new trends in polarography and related techniques

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Advances in chromatography

A report on the 23rd Symposium Advances in Chromatography, New Techniques and Biomedical Applications, held in Chiba, Japan, 6-9 October 1986.

The most recent of the ‘Zlatkis-symposia’ was held this year in Japan, thus providing an excellent opportunity for the more than 200 Japanese and about 50 foreign chromatographers participating in the symposium to acquaint themselves with each others results. The majority of the 60 papers and 76 posters were from those fields where Japanese chromatographers hold leading positions, such as derivatization techniques, chemiluminescence methods, miniaturization and chiral separations as highlighted in the excellent contributions by A. Tsuji, S. Hara, D. Ishii and many others. Of the new techniques high-performance liquid chromatographymass spectrometry (HPLC-MS) and thin-layer chromatography-mass spectrometry (TLC-MS) received great attention. In two very interesting lectures by M. Novotny and D. E. Games, a splendid future was forecasted for supercritical fluid chromatography in the biomedical field. Special mention should be made of ‘high temperature gas chromatography’ which, based on the development in column technology (introduction of aluminium-clad flexible fused-silica capillaries coated with thermostable stationary phases), is likely to revolutionize the GC analysis of lipids. The paper by the pioneer of this field, S. R. Lipsky, was presented by L. S. Ettre because of the sudden death of the author shortly before the symposium. The most memorable event of the symposium was undoubtedly the session on biomedical chromatography held in honour of E. C. Horning, an outstanding personality in the chromatographic analysis of lipids, metabolic studies and many related fields, on the occasion of his retirement. In

addition to the excellent papers presented by E. C. Horning and his wife M. G. Horning, the session was highlighted by contributions from leading experts in this field such as C. C. Sweely, J. Sjovall, T. Nambara, C. J. W. Brooks, H. Miyazaki, W. J. A. Vandenheuvel and N. Ikekawa (cochairman of the symposium),

The symposium was very well organized and the facilities were excellent. The symposium was in all respects worthy of the traditions of the Zlatkis symposia. S. GijRoG S. Giiriig is at Gedeon Richter Chemical Works, P.O. Box 27 Budapest 10, HI475 Hungary.

Trends in polarography and related techniques

A report on the International Symposium on New Trends in Polarography and Related Techniques, Fermo, Italy, 1-4 September, 1986 In the beautiful setting of the Palazzo Dei Priori in the small fortified town of Fermo (south of Ancona) the universities of Bologna and Padova together with the Electrochemistry Division of the Italian Chemical Society organized a well attended meeting with participants from some 19 countries. On the evening before the meeting Professor G. Semerano was awarded the Aquila D’Oro Award for his research and teaching activities. Professor Semerano had early contacts with the inventor of polarography, Professor J. Heyrovsky, and was the driving force of Italian electroanalytical research, the author of the first monograph on polarography and chief editor of Polarographic Bibliography (1922-1968). A.A. Vlcek discussed the present state of polarography and related methods and made some predictions about future trends. He stressed in particular the importance of detailed studies of electrode process mechanisms (molecular level) and of the further development of instrumentation. An example of the first type was the contribution by J.M. Saveant, who discussed redox catalysis of electrochemical reactions involving two or three consecutive chemical reactions of the electrolysis product. Re-

placement of an electrode reaction occurring in the immediate vicinity of the electrode by a reaction occurring in a three dimensional space enables characterization of the nature and chemical properties of short-lived intermediates. Development of instrumentation was reported at the meeting. A newly developed spindle-type polarographic capillary, with improved stability and reproducibility (e.g., a droptime of 70 s reproducible - at constant potential - to + 0.001 s) was described. Such properties enable exact and reproducible measurement of electrocapillary curves and in practical application increase electrolytic reliability in non-aqueous media. Another promising trend is the device for rapid removal of dissolved oxygen (Ch. Yarnitzky) which should increase the speed of industrial analyses. Progress in the area of square-wave and pulse polarography was represented by description of triple sampling voltammetry (L. Nyholm and G. Wikmark). Future applications will indicate the scope of these special techniques. Examples of the use of amperometric detection in high-performance liquid chromatography (HPLC) demonstrated their applicability for systems oxidized on carbon electrodes. The optimum configuration for mercury electrodes which would extend the range of reducible species is still being sought. Adsorption is often considered by those who are using current-voltage

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curves for fundamental or analytical studies as a necessary evil, and we are grateful to those who are willing to investigate these complex phenomena. Fundamentals of the role of adsorption were discussed by E. Laviron. M. Heyrovsky and I. RiiziC stressed the importance of the rate of establishment of the absorbed layer and the danger of not verifying that the absorption equilibrium has been established. Adsorption also evidently plays a role in the enhancement of oxidation of carbon monoxide in the presence of ad-atoms (such as S, Se, Te) on Pt-electrodes (M. Shibata and S. Motoo). The structural effects of added surfactants (adsorbed at the electrode) on electrode processes were described by R. Guidelli. Applications of polarographic techniques in the field of inorganic chemistry covered groups of two large substitution inert complexes, cobaloximes (G. Costa) and cyanobridged polynuclear ruthenium complexes (S. Roffia, C. Paradisi, C.A. Bignozzi and F. Scandola). H. Berg discussed how light interacts with

species undergoing electrolysis and electrolytic products and gave examples of photocatalyzed reactions. A survey of applications of polarographic and related methods in pharmacy was given by J. Volke. Examples of the use of such techniques in investigation of fast and slow chemical reactions were demonstrated by P. Zuman on reactions of aldehydes, a-diketones and a-ketoacids. Examples of studies of individual organic compounds were presented by E. Brillas and J.J. Ruiz (2-cyclohexenl-one), C. Herrenknecht, E. Guernet and C. Gueutin (pyrazolidine3,5-diones) and F. Maran, F. D’Angeli and E. Vianello (a-bromoamides) . The social program was perfect and the hospitality of the Italian hosts memorable. P. ZUMAN

P. Zuman is at the Department of Chemistry, Clarkson University, Potsdam, NY 13676, U. S. A.

Spectroscopy for biomedical research

A report on the 5th International Symposium on New Spectroscopic Methods for Biomedical Research and Workshop on Biomedical ESCA and FTIR, held in Seattle, WA, U.S.A., 7-11 October 1986 ‘Science is spectrum analysis, art is photosynthesis.’ (K. Kraus) This opening line of the program for the Fifth International Symposium on New Spectroscopic Methods for Biomedical Research embodies the traditional view that physical instrumentation and natural phenomena belong to two different realms of study. However, this symposium emphasized the contemporary view that spectroscopic tools used in the physical sciences are extremely valuable

for solving problems in the biomedical field. In addition to the 28 lectures, the symposium included an exhibition of surface analysis instruments presented by nine companies and a workshop on the biomedical uses of electron spectroscopy for chemical analysis (ESCA) and Fourier transform infrared (FTIR) spectroscopy techniques. Approximately 80 chemists, physicists, chemical and electrical engineers, bioengineers, medical doctors, biochemists and biologists from both industrial and academic environments discussed specialized techniques and biomedical applications of several spectroscopic methods. The symposium was sponsored by the National Center for Biomedical Infrared Spectroscopy (Battelle Columbus Labs.) and the National

ESCA and Surface Analysis Center for Biomedical Problems (University of Washington). Both centers are funded by the Division of Research Resources, National Institutes of Health. The major biomedical applications discussed include (1) biomaterials characterization, (2) polypeptide and cell analysis and (3) biological sensor development. Biomaterlals characterization The nature of the surface of a biomaterial governs the biological interactions with that material. Surfacesensitive techniques such as ESCA and secondary ion mass spectroscopy (SIMS) may be used to describe the surface chemistry. D. Briggs suggested a new ESCA-SIMS combination which overcomes the major disadvantages of each individual method, i.e., the better spatial resolution of SIMS combined with the wider range of element detection by ESCA. Several investigators emphasized that analyzing a material by using both ESCA and FTIR-attenuated total reflection (ATR) spectroscopy also provides a clearer view of the surface composition than one of the methods alone. Novel biomaterials created by using radio-frequency plasma polymerization have been characterized by the ESCA technique. In a study by W. R. Gombotz and A. S. Hoffman, amino and hydroxyl functional groups were polymerized onto polymer films to provide sites for subsequent covalent immobilization of biomolecules and polymers. The treated surfaces were examined by ESCA, which gave a quantitative measure of the degree of surface functionalization, as well as FTIRATR spectroscopy, which provided a qualitative analysis for the presence of functional groups. D. Kiaei and co-workers coated Dacron and Silastic vascular grafts with tetrafluoroethylene (TFE) and analyzed them with ESCA. From a series of in vitro platelet studies, these investigators found that emboli production was much less in TFEtreated grafts. Measuring the biological interactions associated with a biomaterial is crucial to the understanding of how