ANALYTICAL PROCEEDINGS, JANUARY 1993, VOL 30 35 Reti ri ng President’s Address Bridges in Analytical Chemistry J. D. R. Thomas School of Chemistry and Applied Chemistry, University of Wales, PO Box 912, Cardiff CFI 3TB Fifty years ago, come next year, I crossed a bridge in the upper Towy Valley in Wales and travelled along the road beyond the Black Mountain for my further education and life’s work. On looking back from the Mountain, the Carmarthen Vans of the legendary Lady of the Lake and home of the Physicians of Myddfai (who used papaverine-based herbs) are seen on the right, and on the left is the dramatically placed Carreg Cennen Castle. In between, lies rich and scenic agricultural land, which at that time was unpeppered by the new pesticides of the kind discussed in our symposium today (March 27th, 1992) on The Analysis of Fungicides, Herbicides and Insecticides.The Black Mountain itself is one of limestone, silica, peat beds and even an outcrop of coal. From time to time, the silica is quarried for industrial use, and until recently the limestone provided the lime from up to 35 kilns for whitewashing farm buildings and land-liming. The peat, used for conditioning the soil of many a garden, provided me with a topic for analytical chemical study which was later to become the foundation for an academic-industrial bridge. This study linked solvent extrac- tion and ion-exchange chromatographic separation with ultra- violet spectroscopy for monitoring and infrared spectroscopy (Fig. 1) for characterization. The journey fulfilled my ambition to take up chemistry as a career.This ambition was stimulated by my liking for chemistry, and was given direction by an encyclopaedia entry for ‘Chemistry’ which gave The Institute of Chemistry of Great Britain and Ireland as the official organization of the profession (there was little in the way of careers advice in those days). The Institute described the ways forward to its new Student Member. The intervening span from then to the present, the suspension bridge of my life, stretches from the days of classical analytical chemistry to those of the present labour-saving computer-based and data-handling instrumentation with Fig. 1 fractions following solvent extraction and ion-exchange separation Plotting an infrared spectrum in 1962 to characterize peat sophisticated sensors and robotics.Also, by now analytical chemistry often goes froml the laboratory to the bedside, into industrial plant, to the roadside and into rivers and streams. The bridging of analyticial chemistry of the past to that of the present and on to the future will vary in perspective between viewers, but the chasms crossed are essentially the same. To assure the future, the present needs to be used for attracting interest in the young. Analytical chemistry is a superb vehicle for such stimulation and for the teaching of chemistry. It is the central theme used by the Analytical Division in supporting Schools Analysts competitions, and in association with the Education Department of the Society, with sponsorship from the Analytical Chemistry Trust, in producing the brochure ‘Analytical Chemistry’ and the video ‘Chemical Detectives’, each aimed at senior pupils in schools.At present, ‘Anna Lytic’, brainchild of the Division’s Education and Training Committee, again in association with the Society’s Education Department and with sponsorship from the Analytical Chemistry Trust, is being moulded to encourage a younger age group to take interest in chemistry through analytical chemistry. Although the immediate aim is to stimulate interest in chemistry, the ultimate objective is to develop the profession of analytical chemistry, which invar- iably depends on sound training in general chemistry. The transition from school to further education is a significant step; the bridging of this is made no easier by successive government upheavals.On crossing this bridge there are signposts pointing in many directions. For analytical chemistry, there are the three main routes of industry, public service and education. Each of these has bridges, and other bridges interconnect the main trails. Within each trail there may be research orientation, quality control and quality assurance in various guises, diagnostic work, curriculum and other developments, technique specialisms, etc. Rather than philosophize any further, let me now go on and relate to those bridges that have proved prominent in regard to my own life in and for analytical chemistry. These relate to the curriculum, academic-industrial links and international relations. Bridges in the Curriculum Analytical chemistry, by being essentially an experimental study of the composition of solids, liquids and gases, is a keystone for bridging the component parts of chemistry, no matter how they are classified. The teaching of chemistry at tertiary level in the first half of this century embraced practical laboratory instruction geared mainly to classical qualitative and quantitative analysis of inorganic materials, and to synthesis and qualitative analysis of organic compounds.The focus on practical physical chemistry was relatively small. Of course, main courses in chemistry were usually reinforced by subsidiary courses in physics and/or mathematics. Against this background my own view of chemistry could be summarized as one of ‘making’ and analysis, coupled with36 ANALYTICAL PROCEEDINGS, JANUARY 1993, VOL 30 characterization through chemical and physical properties.Working in the plastics industry, and job prospects in other industries, reinforced this view, as indeed did working in the food industy and in a public analyst’s laboratory. Within my undergraduate education there were, more by accident than design, the fundamentals and foundation of much that is now to be seen in modern analytical chemistry. Thus, in addition to a great deal on classical reaction analytical chemistry, there was the basis of understanding of spectro- scopic analysis through quantum theory and wave mechanics and its application through the Lambert-Beer relationship. The principles of electrochemical analysis were evident in the Nernstian view of the theory of the electrode process.Certain gems, like the urease-catalysed hydrolysis of urea, were to become the basis of new electrochemical sensors. Polaro- graphy was well set in our curriculum in the 1940s. However, chromatography, which along with spectroscopy is a mainstay of today’s laboratory instrumental analysis, was yet to cross the divide from biochemistry into chemistry curricula. Inciden- tally, The Analyst, in the RSC Sesquicentenary Celebration Issue in December 1991, is the only primary journal to have paid tribute to the pioneers of modern chromatography. The 1940s saw the foundation of a great surge in analytical chemistry. This was reflected in the growth of membership of The Society of Public Analysts and Other Analytical Chemists from fewer than 1000 50 years ago to about 1600 by 40 years ago. These turned out to be years poised for changes in the curriculum.Microchemical techniques revolutionized quali- tative analysis, and their introduction into the curriculum greatly reduced the timc spent on such analysis (and on organic syntheses), but the time freed was rarely used to promote the newer and instrumental methods of analysis. However, the scene was set for new bridge building, an ever present need in analytical chemistry because of progress, new developments and concerns. Regarding concerns, J. R. Nicholls, who was President of The Society of Public Analysts and Other Analytical Chemists at the time of my admission as a Member in 1952, in his Presidential Address talked of ‘Public Health Hazards and the Analytical Chemist’.He referred to hazards arising from air, water, food, clothing, cosmetics and household materials. It was a far-reaching address, and after considering the hazards he went on to classify them as being due to lack of personal hygiene, contamination and ‘chemicals’ in the widest sense. On chemicals, he made the point that ‘Whatever control measures are envisaged, it seems generally agreed that provision must be made for periodical review.’ Analytical chemistry has to keep pace. Industry and the public service gave me salutary experience on the role of analytical chemistry at work and in daily life (Fig. 2). Up to then, that is, 40 years ago, there was by today’s standards, apart from analytical balances, and perhaps an odd refractometer, polarimeter and simple photometer like the ‘Spekker’, relatively little in the way of instrumentation in chemical laboratories that was not electrochemical.Even the electrochemical equipment tended to be simple units for potcntiometry, conductimetry and electrolysis. The sophistica- tions of pH meters and polarographs were the prerogative of the privileged few. Advances in electronic technology, and micro-electronic solid-state circuitry, had yet to take effect. The local authority controlled colleges of technology (or technical colleges as they were earlier known), through their involvement in National and Higher National Certificates in Chemistry and associated links with industry, came to be equipped in the early 1950s with a range of physicochemical instrumentation.As a procurer of such instruments at the Cardiff College of Technology and Commerce I introduced instrumental analysis alongside microanalytical approaches to undergraduates of chemistry and pharmacy. This was in addition to fulfilling the needs of day-release Higher National Certificate and other students. It was also possible to innovate with undergraduate student projects, such as by the construc- tion of a gas chromatograph , separations by electrophoresis and X-ray characterizations. Although those were days of relative rigidity in curricula, governed by entrenched views in universities, and by ex- aminers of external University of London degrees and of examinations for The Royal Institute of Chemistry, it was still possible to elucidate the more theoretical concepts effectively by bridging with pertinent analytical chemistry. Such bridging became easier as the years wore on.The experience proved invaluable for designing dedicated courses in analytical chemistry as new qualifications emerged, that is, courses like the Diploma in Technology and Endorsements to Higher National Certificates. The latter was soon to lead on to Licentiateship of the Royal Institute of Chemistry. Since then there have been many changes, such as the Diplomas in Technology becoming degrees of the new technological universities and of the CNAA, and further changes are afoot with the recent passing of the new Higher and Further Education Bill. Among all this, it was my privilege in 1958 to set up the first ever Higher National Certificate (HNC) Endorsement Course in Analytical Chemistry in the United Kingdom at the South East Essex Technical College, and later to have analytical chemistry incorporated in its own right into undergraduate curricula.To me, as a member of the Society that in 1954 became the Society for Analytical Chemistry, much of the inspiration and indeed tacit endorsement of my actions came from the papers, published in The Analyst of November and December 1952, presented at the First International Congress on Analytical Chemistry held under the Patronage of IUPAC at Oxford in September 1952. The presentations were in eight sections devoted, respectively, to microchemical methods, biological methods, electrical methods, optical methods, radiochemical methods, organic complexes, presentation of data, and adsorp- tion and partition methods.These papers succinctly bridged the theoretical principles of chemistry and science in general with the analytical approaches of such diverse methods as solvent extraction, square wave polarography, equivalence point determination (Gran’s plots), chelating ligands, infrared spectroscopy, statistics, gas-liquid chromatography, and ion exchange. The IUPAC Congress was one that blazed the trail for Analytical Chemistry, and laid hopes. Sir Robert Robinson, President of the Congress, is recorded to have ‘deplored the fact that the University (Oxford) had not yet got a Chair of Analytical Chemistry. At least four Chairs of Chemistry were needed: Physical , Organic, Inorganic and Analytical’. We are still waiting! Fig.2 At work (right) in an industrial control laboratory in 1950. when modern physicochemical instrumentation was yet to be in common uscANALYTICAL PROCEEDINGS, JANUARY 1993, VOL 30 37 In the interim there seems to have been a lag in the developing perception of analytical chemistry. At the Con- gress, Norman Sheppard gave account of advances in the design of infrared spectrometers for incorporation in instru- ments designed for analytical work. Forty years on, Sheppard was among those honoured in March 1992 at The Third James L. Waters Annual Symposium set up to Recognize Pioneers in the Development of Analytical Instrumentation which at Pittcon ’92 ‘Saluted Infrared Spectroscopy’. The Analytical Division has only recently had a Molecular Spectroscopy Group! Today’s trend for having modular schemes of study and the changes that will inevitably result from the Higher and Further Education Bill provide excellent flexibility for bridging con- cepts through analytical chemistry and thus to portray a relevant perspective of chemistry.However, with pressure on curriculum time it will be necessary to be on the offensive (the best line for progressive action) in order to ensure proper regard for analytical chemistry. Education and training has to be aimed at placing the new graduate in a position to be able to perform adequately, not just as an analytical chemist, but also for graduates in chemistry to be effective in diverse ways, for example, as better synthetic chemists by more intelligent use of essentially analytical type approaches, such as gel permeation chromatography for purifying products, and sampling pro- cedures and quantification methods for purity assessment.Academic-Industrial Bridges There can be no doubt that in order to establish methods of analysis much fundamental research or investigation work of an academic nature must be carried out. Therefore, having regard to the front-line role of analysis in manufacturing and commerce, bridging links between academic institutions and industry are paramount in the development of analytical chemistry. There are various ways for effecting these, includ- ing: (i) encounters at scientific meetings, such as those of the Analytical Division of The Royal Society of Chemistry; (ii) interactions through industrial training of students on sandwich courses; (iii) interactions through vacation employment, day release of students, short courses and graduate recruitment; (iv) job changes (industry to academic life and the reverse); (v) research co-operation through funding by industry or in co- operation with funding agencies, such as the Science and Engineering Research Council (SERC) and the Analytical Chemistry Trust; and ( i v ) consultancies, industrial professor- ships and lectureships.The first three are relatively informal, but they are essential ingredients in establishing rapport between the two sectors. They have the benefits of cultivating expert contacts for quick advice in problem solving. Regarding (i), it was in the 1986 Presidential Address of the Analytical Division that the view was expressed that it might be to the benefit of employers if credit in promotion and salary progression were given to employees attending appropriate scientific meetings.This certainly now figures in staff appraisal schemes of some universities. The matter might be on a points system, such as that detailed in a note on page 51 of the PITTCON ’92 programme relating to accreditation: ‘The American Board of Industrial Hygiene awards f point for each t day attendance at the Pittsburgh Conference’. Since the originator of the suggestion is involved with the Society’s Register of Analytical Chemists maybe we shall in due course see similar points awards for the Register. From personal experience, I consider the benefits of job transition from industry to academic life and vice versa to be invaluable. They serve to develop the ability to recognize problems, to determine priorities and to inspire ideas.The remainder of the above bridging links frequently derive from the others. However, the origins of research links may be more discrete, as I found from research on peat constitution. In Fig. 3 Preparing the Presidcntial Address in 1992 that work, the ion-exchange separation following a solvent extraction stage had resolved phenolic materials, aromatic and aliphatic esters. Further work on the ion-exchange behaviour of phenols, presented at a meeting of the Chromatography and Electrophoresis Group of this Division, attracted attention from industry and led to consultancies and a lengthy 15 year period of sponsored research.The sponsored research yielded a polystyrene-based support and mixed solvent electrolyte system for the electrophoresis of oil-soluble materials, insight into bacteriological initiation of corrosion, a computer-based monitoring system for process streams, and some insight into changes in oil additives during engine wear. There were also incidental rewards in the field of potentiometric ion sensors as in the polarography of imida- zoles. This was a rich harvest. Certainly, academic-industrial bridges can result from a lengthier list to include: (i) computerized file records by industry to keep track of academic research; (ii) lectures by academics and industrialists to indicate mutuality of interests; (iii) pressure by grant-awarding bodies (SERC-CASE awards, SAC Studentships, DTI LINK schemes, etc.); and (iv) the old- boy network.The third method of this secondary list extends to the broader role of the Science and Engineering Research Council (SERC) in the funding of academic research. This is aimed at exploitation of academically based research, and is also designed to promote a wider base for the funding of research. Personal experience has demonstrated this to be a superb catalyst for building strong bridges with various industries. It has also served to bridge multidisciplinary groups, that is, by linking groups of sophisticated organic systhesis and structural determination with our expertise in potentiometric and piezo- electric quartz crystal types of chemical sensing. Of special interest to our Symposium on Pesticide Analysis is the role of crown ethers, particularly dibenzo-30-crown-10 (DB30C10) and its derivatives as ion-selective electrode (ISE) sensors for diquat (DQT) and paraquat (PQT), the best ISE membrane being based on DB30C10 with DQT tetraphenylborate and 2- nitrophenyl phenyl ether in PVC.Of the DB3nCn derivatives, the maximum stability with DQT occurs when n = 10, that is for DB30C10. An X-ray structure shows the plan of the DQT molecule to be enclosed in a U-shaped cavity formed by DB30C10, facilitated by three DB30C10 (host)-DQT (guest) interactions. (i) DB30C10 catechol-oxygen electrostatic interaction with the positively charged nitrogen atoms in DQT. For this, the crown ether catechol 0-0 separation (2.6 A) and N-N separation in DQT (2.8 A) are similar, so that the former are nearly directly above and below the latter in the [DQT.DB30ClO]’+ complex.(ii) DB30C10 benzene ring n-electron charge transfer to the electron deficient DQT’+. (iii) Hydrogen bonding between H38 ANALYTICAL PROCEEDINGS, JANUARY 1993, VOL 30 atoms on the carbons next to the nitrogens in DQT with oxygen atoms in the DB30C10 framework. International Bridges Analytical chemistry, as well as several other subject disci- plines in Britain, and indeed in most developed countries, has benefited from the influx of researchers from foreign countries. In meeting their desires to study and gain experience in many areas, such people have provided seed-corn for subsequent formal funding by their work on essentially speculative projects. This feature is well illustrated by the studies of an overseas student on the ion-sensing qualities of electrode membranes based on metal complexes with polyalkoxylates.Such systems also demonstrated electrochemical sensing quali- ties for polyalkoxylates themselves, and led to several funded projects and to sensors for alkoxylate type non-ionic surfactants. Other examples of our experience of the helpful roles of overseas research workers consist of initiating work on enzyme-based biosensors, subsequently funded by the Depart- ment of Trade and Industry and by industry itself; studies of the stability of ion-exchange resins in non-aqueous media which led on to the ion-exchange separation of phenols and then to industrial sponsorship of other projects; polyurethane foam chromatographic and extraction studies; and piezoelectric quartz crystal detection of gases and vapours.Particularly exciting has been the demonstration of the role of ring type epoxyoctahydro[ 12lcyclacene and of certain chemically modi- fied cyclodextrin derivatives as piezoelectric quartz crystal coating sensors for aromatic vapours. This last example is like a multi-arch viaduct or aqueduct, by also involving SERC and academic-academic links. As a result of research in Britain, trained personnel have returned to foreign countries with a wealth of expertise for embarking on their own programmes. Apart from the obvious electrochemical ion-sensing, our own research degree gradu- ates have gone forth with experience of nuclear magnetic resonance and other spectroscopic approaches, immobilization of enzymes and their characterization, chemometric principles, microbiological approaches, dielectric and thermal measure- ment expertise, etc.It is gratifying that the Analytical Chemistry Trust, through the SAC Studentship Scheme, has participated indirectly in this by coincidentally supporting an oveseas student graduate of a British university (helped also by the Overseas Research Studentship Scheme of the Committee of Vice-Chancellors and Principals). In this way, there has been high-level support of developing countries to complement the salutary initiative of the Analytical Chemistry Trust in supporting VSO (Voluntary Service Overseas) teachers. Presentation of research at conferences and during consul- tations and other activities in foreign countries, and in reverse by listening to visitors to Britain, provides forums for learning of interests of prospective research collaborators. The present day ease of travel and communication, compared with even a quarter of a century ago, makes for rapid bridge building, to the benefit of analytical chemistry.However, the closeness with the far reaches of the world, created by air travel and satellite communication, whilst promoting rapid progress and development, can hinder the generation of completely novel ideas. This is because of a natural desire to follow fads and fashion rather than undertake brainstorming sessions. . On a broader front, methods of analysis and the interpre- tation of numerical data and figures thereby obtained have to be international. It is not sufficient for duplicates of an analysis to agree, satisfying though that maybe.Replicates must also agree, and these conducted not by one individual worker or at one laboratory, but by several. It is on the basis of such agreements that contracts of national and international trade and commerce can be properly conducted. The imminence of the European single market has brought the need for confidence in the uniform definition of chemical ingredients through analysis into stark perspective. Hence, bodies like EURACHEM, advised in this country by CHEMAC (the Chemical Measurement Advisory Committee run by the Laboratory of the Government Chemist) have come into being. Of course, such bodies are complementary to The International Standards Institution (ISO) and its national adhering body, The British Standards Institution (BSI). Our own Analytical Methods Committee of the Analytical Division, apart from bringing together and promoting co- operation between people of diverse interests, has bridged the Atlantic Ocean in an understanding with the Association of Official Analytical Chemists.On a stronger footing is the affiliation of the Analytical Division to the Federation of Analytical Chemistry and Spectroscopy Societies (FACSS), which in the autumn of 1991 resulted in a Division-sponsored symposium on atomic spectrometry at the Anaheim FACSS Meeting. Capillary zone electrophoresis is planned to be Division-sponsored at the FACSS Meeting of 1993. Finally, in international bridging, there is the International Union of Pure and Applied Chemistry which emphasizes international agreement, and significantly has a Division of Analytical Chemistry. Similarly, the Federation of European Chemical Societies (FECS) has its Working Party on Analyti- cal Chemistry, which is very active in the European scene of bridging in analytical chemistry. To mark the Sesquicentenary in 1991 of the founding of the Chemical Society in 1841, the Analytical Division through the Analytical Chemistry Trust sponsored The Robert Boyle Anniversary Fellowship in Analytical Chemistry of The Royal Society of Chemistry. The Fellowship was held by Professor Alan M. Bond of La Trobe University, Australia, during 1991 at the University of Oxford. Conclusion Analytical chemistry is an advancing science, and because of its many implications in daily life and work, it has to be an organized science. In such roles it has to meet challenges, as do all who are engaged in it. Bridges help to overcome these challenges and to promote progress and understanding.