2 JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY FEBRUARY 1991 VOL. 6 Atomic Spectrometry Viewpoint Barry L. Sharp Chemistry Department Loughborough University of Technology Loughborough Leicestershire L E 1 1 3TU UK The Hilger Spectroscopy Prize was inaugurated in 1975 by the Atomic Spectroscopy Group of The Royal Society of Chemistry. The Prize is awarded to the young person (under 35 years of age in the year the award is made) who in the opinion of the Committee has made a significant contribution to atomic spectroscopy. It is customary for the recipient to give a lecture on their specialist topic at an ASG meeting within the preceding twelve months. It is timely to review how the first winner of the prize Barry Sharp (B.L.S.) has emerged in the field of atomic spectroscopy in the subsequent 15 years.An interview with Barry Sharp was arranged at the recent 5th Biennial National Atomic Spectroscopy Symposium (BNASS) at Loughborough University of Technology. The interview was conducted by Dr. John Dean (J.D.) (Honorary Secretary) and Dr. John Marshall (J.M.) (the then Vice-chairman). J.D. Can you tell us how you came to be the first recipient of the Hilgel- Spectros- copy Prize and which particular aspects of your work did it recognize? B.L.S. I joined the research group led by Professor Tom West at Imperial College in 1972 and worked on the development of microwave plasma emission spectrom- etry for trace metal analysis and the de- velopment of photon counting systems for atomic spectrometric measurements. Inductively coupled plasma work had just begun in our laboratory and it was evident even then that the ICP source was as near ideal for solution analysis as we were going to get.The microwave plasma was an extremely efficient excitation source for vapours and gases but the poor atomization properties excluded it from consideration as a source for hand- ling solutions. The work on photon count- ing was stimulated by the contemporary enthusiasm for atomic fluorescence spec- trometry (AFS) whose coming appeared to be only the invention of a stable tunable pocket laser away. It is still coming. I received my PhD in 1972 and having joined the staff as a lecturer I made a successful application to the then SRC for equipment to study laser excited atomic fluorescence spectroscopy (LAFS). The SRC believed in doing things by halves and so with half the money I had asked for I purchased a flash lamp pumped tunable dye laser.I had no detection equipment so this I bor- rowed from the physicists and the project proceeded on the days when they did not need their equipment. The intention was to investigate the potential of LAFS as an analytical technique but the laser simply wasn’t reliable enough and so the project developed into a study of saturation and quasi-coherent phenomena in atomic vapours. It was at this time that I re- ceived the Hilger Spectroscopy Prize al- though the laser work was not published until 1976 when it appeared in Spectro- chimica Acta . J.D. You lejl Imperial College in 1975 and went to work at the MacaulayJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY FEBRUARY 199 1 VOL.6 Barry Sharp ( L ) with John Carroll Institute for Soil Research (now the Ma- caulay Land Use Research Institute) what prompted this move? B.L.S. Simply that Tom West left Im- perial College to become Director of the Macaulay and offered me a job. J.D. What was your role at the Macaulay? B.L.S. Broadly to develop and implement spectroscopic methods of analysis that might be useful for the analysis of agri- cultural and environmental samples. My first project was to find a suitable method for the field measurement of SO2 one that could be used in remote and inaccessible terrain. One approach was to use an optical radar system i.e. LIDAR (light detection and ranging) in a differen- tial absorption (two wavelength) configuration.I already had the laser system which I had taken with me from Imperial College and so work began to construct a system. It took the efforts of two postgraduate students before we had a working (some days) instrument which was pointed out of one of the upstairs windows of the Institute. As an aside the system had some 64 control routines op- erating its various functions all running on one of the early Intel 8080 micropro- cessor chips which we obtained on a pre- release demonstration board. Once again however the unreliability of the laser particularly when operated in a switched two wavelength mode was unacceptable for a routine instrument. Thus with money running out the project was dropped. J.D. How did your work on nebulizers begin ? B.L.S. This goes back to my time at Im- perial College when one of my postgradu- ate students John Goulter was sponsored by a cement company to investigate the possibility of the direct nebulization of cement powder into an ICP.Needless to say this proved almost impossible to achieve but we had a lot of fun trying and in the process my interest in nebuliz- ers was born. Moving forward to the early 1980s my second major project at the Macaulay was to investigate the pos- sibility of using ICP-AES for the analysis of soil and plant extracts. We did not have sufficient funds to purchase a com- mercial instrument so we bought a source unit and I constructed a system from equipment that we had in the laboratory. The nebulizers available at that time did not seem to be particularly good for our samples and so I decided to make my own and thus my interest was rekindled.The ICP instrument went into routine op- eration and I also became gradually more and more involved in the analytical service operation. The nebulizer work proceeded in fits and starts whenever I had the time to fit it in. An important step at least in terms of the practical con- sequences of the work came in 1985 when in investigating the sources of noise produced by nebulizers which is largely the result of the re-entrainment effect I realized that re-entrainment could be used to improve the gas-liquid interaction in a Babington-type nebulizer. This led to the development and patenting of the Cone- spray nebulizer. The patent was taken out because I was doing some consultancy work with the Royal Aircraft Establish- ment at Farnborough Hampshire UK and it appeared that the device might be useful for fuel spraying in aero-engines this however was not the case.The Conespray consists of a sapphire nozzle with a conical expansion section beyond the nozzle throat. Solution introduced on to the front face of the nozzle adjacent to the conical expansion is drawn down the cone and nebulized from an annular ring close to the nozzle throat. Our laboratory device used a 70 pm nozzle and operated at 250 psig. Although very efficient the high pressure excluded its use on com- mercial ICP systems. Recently however Perkin-Elmer has started marketing a scaled-up version of the Conespray which operates at 30 psig. Although originally developed as a high solids nebulizer the device works equally well with pure solu- tions provided that sufficient sample is pumped to wet the majority of the nozzle throat perimeter In the commercial version this requires about 2 ml min-l but was less than 1 ml min-’ in the origi- nal high-pressure device. This and other developments were described in two reviews which appeared in JAAS in 1988.J.D. This brings us to the present when you have just indicated that you are taking up an appointment at the Univer- sity of Loughborough. What are your plans for the future? B.L.S. I should first say that it was with regret that I decided to leave the Macau- lay but as the Head of the Analytical Division I had become a full time admin- istrator and I wished to return to active re- search.J.M. Will you be concentrating on atomic spectroscopy at Loughborough or will you be involved in a wider range of activ- ities? B.L.S. Inductively coupled plasmas will continue to be my main interest and whether the work involves optical or mass spectrometry sample introduction will be a part of it. I would like to do some more work on atmospheric monitor- ing and perhaps some of the recent devel- opments that have taken place in solid- state lasers might make this a pertinent time to return to this field. J.D. How do you intend to fund these ven- tures? B.L.S. Well sitting next to John Marshall from ICI a potential solution is close at hand. I think that one has to be realistic. As an academic one has to explain one’s ideas to people and hope that they are willing to fund them.Potential sponsors often have their own ideas that they would wish to pursue and hopefully common ground can be found that produces inter- esting research that is academically chal- lenging has practical benefit and provides a good training for our students. J.M. Do you have a view on the academic situation in the UK having been in a quasi-industrial environment? B.L.S. I think that some of my colleagues in academia must think that I am mad coming back to it. Academic research has hardly had a golden period in the UK and it is recognized that it is grossly under- funded. We do have the problem now that when we look at companies like ICI and see what they are doing we cannot afford to train the students in the techniques in which they are interested. I do not see an easy solution to this problem.One ap- proach is for the Universities and Poly- technics to accept that they cannot provide the facilities required and for in- dustry to take a much greater role in train- ing. Academics would continue to teach the basic skills but practical experience would be provided outside the education- al institution. The difficulty with this ap- proach is that unless we get practical hands-on experience the quality of our teaching will suffer. Every teacher at some stage has to give courses in subjects of which they have limited practical ex- perience and one is always aware that the students are receiving a lower quality product. J.M. Does this mean that you see us moving to a situation where more and more postgraduates carry out their research in the laboratories of their sponsors? B.L.S.Unless central government in- creases the level of funding this is inevi- table. A benefit of this is that the postgraduates so trained should at least4 JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY FEBRUARY 1991 VOL. 6 have a clearer concept of what the real world is like. However I repeat that if ac- ademics have to do all their research at arms length they will be impoverished as teachers. J.M. I think that there has been a view in Universities that industrial type problems are not really suitable for academic post- graduate research whereas in fact there are quite a few problems that do have a theoretical base that could be examined. B.L.S. The difficulty for industry is that if you have a problem it is not feasible for you to spend the kind of money needed to solve that problem in a University depart- ment.In other words you are not going to buy an ICP-MS or SIMS and give them to a University and say solve the problem for us. This is in part because you recog- nize that they are unlikely to solve that specific problem anyway. Having come from a research institute background it is my view that the initiators usually have a greater understanding of the problem and its context and are therefore best placed to deal with the specifics. What you can hope for is that through your input and other financing that the academic com- munity can acquire the necessary resourc- es and provide a background of science and understanding that you can draw upon.Universities should on the whole concentrate on the science and attempt to establish the boundary conditions for analytical techniques so that their practi- cal implementation is soundly based. J.M. Do you think that atomic spectro- metry has a long-term future? B.L.S. I’m sure that it has but it will evolve and be different from the way we know it now. For example I believe that mass spectrometric detection will ulti- mately replace optical detection to a much greater extent than is currently the case. Our colleagues in the environmental and biological sciences are very impressed with what we can measure using modem techniques but we are not measuring what they require. Primarily they need to know the state of chemical equilibria in situ in the soil solution in the plant membrane inside the cell. Unfortunately atomic spectroscopy is not well placed to deal with these problems. For large molecules immuno-techniques have in some cases provided highly specific reactions that can be monitored by conventional means but there is no parallel for small molecules. Additionally all of our current techniques including chromatography disturb the delicate equilibria that we would like to study. This is the challenge to take analyt- ical chemistry out of the laboratory and to answer the real questions. J.P. The last 1.5 years have obviously been interesting and successful. We would like to thank you for comments and wish you luck in your new position.