t h a t they require t h a t reagent be dif fused into t h e sample. In t h e U 0 2 + sensor, p h o s p h a t e and nitric acid are diffused into t h e s a m p l e to g e n e r a t e a m e d i u m in which U 0 ' 2 + becomes fluo rescent. In t h e halide sensor, Ag-fluorescein is diffused into t h e sample. Halides combine with A g + , rendering fluorescein fluorescent.
The Future Chemical sensors based on fiber op tics are clearly attractive in concept. Success in practice requires t h e devel o p m e n t of a p p r o p r i a t e reagent phases. T h i s process is only beginning. How ever, t h e devices developed t o d a t e al ready illustrate t h e wide variety of a p proaches and systems t h a t a r e pos sible. I n t e r e s t in optical sensors is certain t o intensify in t h e n e x t few years, a n d t h e r e are some t r e n d s t h a t are likely t o emerge. Because t h e d y n a m i c r a n g e of sensors is limited and d e p e n d s on equilibrium c o n s t a n t s , a series of re a g e n t phases will be developed for a single analyte in order to respond to different levels of analyte concentra tion. O t h e r p r o b a b l e t r e n d s will be t h e increased use of m e a s u r e m e n t s a t two or m o r e wavelengths a n d t h e in creased use of reflectance t o exploit
reactions causing color changes. Successful d e v e l o p m e n t of optical sensors t h a t respond directly to com m o n analytes will inevitably lead to coupled sensors in which a r e a g e n t p h a s e " t r a n s d u c e s " t h e a n a l y t e of in t e r e s t t o a species m e a s u r e d by t h e op tical sensor. As already m e n t i o n e d , optical p H sensors in c o n t a c t with bi c a r b o n a t e have already served as t h e i n t e r n a l sensing e l e m e n t s of C 0 2 sen sors (8, 14, 15).
(12) Kawahara, F. K.; Fiuten, R. Α.; Silvus, H. S.; Newman, F. N.; Frazar, J. H. Anal. Chim. Acta 1983,151, 315. (13) Freeman, T. M.; Seitz, W. R. Anal. Chem. 1981,53,98-102. (14) Zhujun, Z.; Seitz, W. R., submitted for publication in Anal. Chim. Acta. (15) Vurek, G.; Peterson, John; Goldstein, Seth; Severinghaus, John. Federation Proceedings 1982,4/, 1484.
References (1) Borman, S. A. Anal. Chem. 1981,53, 1616-18 A. (2) Peterson, J. I.; Goldstein, S. R.; Fitz gerald, R. V.; Buckhold, D. K. Anal. Chem. 1980,52,864-69. (3) Saari, L. Α.; Seitz, W. R. Anal. Chem. 1982 54 821-23. (4) Saari, L. Α.; Seitz, W. R. Anal. Chem. 1983,55,667-70. (5) Saari, L. Α.; Seitz, W. R., submitted for publication in Analyst. (6) Zhujun, Z., unpublished work. (7) Zhujun, Z.; Seitz, W. R., submitted for publication in Anal. Chim. Acta. (8) Lubbers, D. W.; Opitz, N. In "Proceed ings of the International Meeting on Chemical Sensors"; Fukuoka, Japan; El sevier: Amsterdam, 1983; pp. 609-19. (9) Peterson, J. I.; Fitzgerald, R. V.; Buckhold, D. K. Anal. Chem., 1984,56, 62-67. (10) Schultz, J. S. U.S. Patent 43 444 38, 1982
(11) Giuliani, J. F.; Wohltjen, H.; Jarvis, N. L. Opt. Lett. 1983,8, 54-56.
FITTINGS for LIQUID CHROMATOGRAPHY
Rudolf Seitz received his PhD from MIT in 1970. After working at the EPA's Southeast Environmental Re search Laboratory and at the Univer sity of Georgia, he joined the faculty of the University of New Hampshire in 1976. Although his earlier research dealt with chemiluminescence, he is now primarily interested in fluores cence and the development of optical sensors.
Roger Adams: Scientist and Statesman by D. Stanley Tarbell and Ann Tracy Tarbell Examines the life of Roger Adams — a man unparalleled in his contribution to the development of organic chemistry.
A comprehensive biographical s k e t c h of R o g e r A d a m s , w h o s e w o r k w a s i m p o r t a n t in the d e v e l o p m e n t of American chemistry and chemical e d u c a t i o n . A d a m s ' s early y e a r s , e d u c a t i o n , a n d c a r e e r a c h i e v e m e n t s in a c a d e m i a , industry, r e s e a r c h , a n d government are described. CONTENTS Introduction · Early Years and College · Germany and Harvard. 1 9 1 2 - 1 6 · Illinois, 1916-26 · Academic Progress · Service and Research to 1942 · Government Service, 1940-48 · Illinois and Research, 1943-67 · Broader Horizons · Career Achievements of Roger Adams's Ph.D.s, 1918-58 · Career Achievements of Roger Adams s Postdoctorates, 1936-59 240 pages (1981) Clothbound US & Canada $13.95 Export $16.95 LC 81-17625 ISBN 0-8412-0598-1
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