Letters
THE CVC SUPERSPEC600... a speed demon in process gas analysis.
ELISA
The Superspec 600 utilizes a unique integrated mass spectrometer concept which enables it to display the relative abundance of a number of gases in less than one second. Accurate, sensitive down to 5 ppm levels, and reliable, Superspec 600 is invaluable in controlling manufacturing processes, monitoring pollution, leak detection, and a wealth of other applications. The system is self contained, portable and can withstand harsh industrial environments. And the Superspec 600 is priced less than other systems which can't measure up to its speedy performance. For complete specifications on this superior system, contact CVC today.
CVC
PRODUCTS, INC.
5 2 5 Lee Road, P.O. Box 1 8 8 6 Rochester, N.Y. 1 4 6 0 3 ( 7 1 6 ) 4 5 8 - 2 5 5 0 Telex: 9 7 - 8 2 6 9
See us at Pittsburgh Conference
Booths 910-912
CIRCLE 36 ON READER SERVICE CARD
LOW-GtST.UKII PBtFORMHMCE POLARIMETERS AND SACCHARIMETERS FOR RESEARCH, ANALYSIS AND CONTROL The Autopol series are high precision, quality state-of-the-art instruments available at a price lower than all other automatics and even lower than many manually operated polarimeters. The only operating controls are two pushbuttons, Power and Reset, all other functions are fully automatic. For all the details contact the Polarimetry Experts, Rudolph Research, 40 Pier Lane, Box 1446, Fairfield, N.J, 07006 (201) 227-6810.
Sir: A new immunoassay technique has been developed. This technique is superior to radioimmunoassay (RIA), voltammetric immunoassay [Anal. Chem., 51, 1182 A (1979)], and fluo rescence immunoassay [Anal. Chem., 51, 33 A (1979)]. This new method called enzyme linked immunosorbent assay (ELISA), as reported in Hospi tal Practice, (p 121, December 1978) is more sensitive, specific, safer and less expensive. T h e assay has a colorimetric end point which can be visual ized easily. A N A L Y T I C A L
CHEMISTRY
should consider inclusion of ELISA in future immunoassay articles for the benefit of those scientists still struggl ing to replace RIA with other methods. Dan Monroe Department of Medicine University of Tennessee Center for Health Sciences Memphis, T e n n . 38163
Standardization of Photometric Detectors Sir: A Standard Practice (SP) for testing fixed-wavelength photometric detectors, t h e most commonly used detectors in H P L C , has been devel oped by a task group of Committee E-19 on Chromatography of t h e American Society for Testing and Ma terials (ASTM). T h e procedures contained in this S P provide t h e means for verifying the performance of any fixed-wavelength photometric detector, for monitoring the changes in a specific detector's performance, and for comparing t h e performance of different photometric detectors. Additional purposes of this method are to effect standardization of detector specifications and to satis fy t h e requirements of good laboratory practices. T h e method appears as S t a n d a r d Practice Ε 685 in t h e 1979 Annual Book of A S T M Standards P a r t 42. Copies are available from the writers below or may be ordered as a single method from ASTM, 1916 Race St., Philadelphia, Pa. 19103. Georgia T. Fritz Los Alamos Scientific Laboratory P.O. Box 1663, MS 920 Los Alamos, N.M. 87545
RUDOLPH RESEARCH
the Polarimetry Experts
See us at the Pittsburgh Conference, Booths 2 0 1 7 - 2 0 1 9 CIRCLE 181 ON READER SERVICE CARD 218 A · ANALYTICAL CHEMISTRY, VOL. 5 2 , NO. 2, FEBRUARY 1980
Thomas Wolf Colgate-Palmolive Co. 909 River Rd. Piscataway, N.J. 08854
