Peak separation you've never seen before.
in their infancy. Both look quite promising. One or both of these vari ants of coherent R a m a n spectroscopy may give analytical chemists the means to obtain Raman spectra of flu orescent materials at trace concentra tions within the next year or two.
Acknowledgment T h e authors thank G. Patrick Ritz and Jeanne Haushalter who have been extensively involved in the develop ment and applications of our coherent R a m a n system.
References
* INSTEAD OF THIS
THIS
New from this X-ray fluorescence analyzer.
A new and unique pulse processor gives our SPECTRACE™ analyzer guaranteed resolution of 150 eV —the best ever achieved in an energy-dispersive X-ray fluorescence analyzer. This resolu tion, coupled with peak shifts no greater than 3 eV at maximum count rate, lets you detect light elements more reliably and quantify them more accurately. The spectrum at left above shows an actual peak separation using the new pulse processor. That at right, with overlapping peaks, was made using a conventional processor in the same analyzer. SPECTRACE 440 can make auto matic unattended analyses of up to
40 samples —solids, liquids, powders or deposits on filter paper. Makes qualitative and quantitative analyses of all elements from Na to Pu. Han dles samples from 1 mm in diameter to a foot high. Has superb sensitivity, repeatability and long-term stability. Our applications laboratory and engineering group will work with you to help solve your analytical problem. That way you know you'll get the results you want after your SPECTRACE is delivered. Over 50 SPECTRACE analyzers are now in use. And we'll give you the name of every single user— because we know every one will give you a favorable report. One thing they'll report is the service they get: personal instruction, an applications school, software school—and follow-up visits just to make sure you're getting the most out of your SPECTRACE. Send for our highly informative brochure now. Contact United Scientific Corporation, Analytical Instrument Division, Dept. C, 1400 Stierlin Road, RO. Box 1389, Mt. View, California 94042. Phone (415) 969-9400.
See SPECTRACE at the Pittsburq Conference, Booths 1702 & 1704
UNITED SCIENTIFIC ANALYTICAL INSTRUMENTS DIVISION CIRCLE 212 O N READER SERVICE CARD
190 A · ANALYTICAL CHEMISTRY, VOL. 5 1 , NO. 2, FEBRUARY 1979
(1) C.-W. Tsai and M. D. Morris, Anal. Chim. Acta, 76,193 (1975). (2) L. C. Hoskins and U. Alexander, Anal. Chem., 49, 695 (1977). (3) J. Behringer, in "Molecular Spectros copy, Specialist Periodic Reports," R. F. Barrow, D. A. Long, and D. J. Millen, Eds., The Chemical Society, pp 170-3, London, England, 1974. (4) J. Behringer, ibid., Vol. 3, pp 163-280, 1975. (5) B. B. Johnson and W. L. Peticolas, Ann. Rev. Phys. Chem., 27, 465 (1977). (6) T. G. Spiro and P. Stein, ibid., 28,501 (1977). (7) A. Warshel, Ann. Rev. Biophys. Bioeng., 6, 273 (1977). (8) T. G. Spiro, in "Vibrational Spectra and Structure," J. R. Durig, Ed., pp 101-20, Elsevier, Amsterdam, The Neth erlands, 1976. (9) J. Brandmiiller, Z. Anal. Chem., 170, 29 (1959). (10) R.J.H. Clark, in "Advances in InfraRed and Raman Spectroscopy," R.J.H. Clark and R. E. Hester, Eds., Vol. 1, pp 143-72, Heyden, London, England, 1975. (11) C. W. Brown and P. F. Lynch, J. Food Sci., 41,1231 (1976). (12) L. VanHaverbeke, P. F. Lynch, and C. W. Brown, Anal. Chem., 50, 315 (1978). (13) R. J. Thibeau, L. VanHaverbeke, and C. W. Brown, Appl. Spectrosc, 32, 98 (1978). (14) M. D. Morris, Anal. Chem., 47, 2453 (1975). (15) M. S. Rahaman and M. D. Morris, Talanta, 23, 65 (1976). (16) M. D. Morris, Anal. Lett., 9, 469 (1976). (17) D. L. Jeanmaire, M. R. Suchanski, and R. P. Van Duyne, J. Am. Chem. Soc, 97,1699 (1975). (18) J. L. Anderson and J. R. Kincaid, Appl. Spectrosc, 32, 356 (1978). (19) W. H. Woodruff and G. H. Atkinson, Anal. Chem., 48,186 (1976). (20) W. H. Woodruff and S. Farquharson, ibid., 50,1389 (1978). (21) P. J. Trotter, J. Phys. Chem., 82, 2396 (1978). (22) H. Yamada, Y. Amamiya, and H. Tsubomura, Chem. Phys. Lett., 56, 591 (1978). (23) P. P. Yaney, J. Opt. Soc. Am., 62, 1297 (1972). (24) R. P. Van Duyne, D. L. Jeanmaire, and D. F. Shriver, Anal. Chem., 46, 213 (1974). (25) F. E. Lytle and M. S. Kelsey, ibid., ρ 855. (26) J. M. Harris, R. W. Chrisman, F. E. Lytle, and R. S. Tobias, ibid., 48,1937 (1976). (27) S. Burgess and I. W. Shepherd, J. Phys., E, 10,617 (1977). (28) A. B. Harvey, Anal. Chem., 50,905A (1978).