REPORT
New CRS
11
Fully Automatic Digital Integrator
First with New Features, Proved Results The CRS-11 you invest in n o w incorporates features that will not be matched in other equipment for years. Your investment in leadership will provide extra benefits n o w , plus extra years of outstanding performance while similar integrators are "catching u p . " T h e CRS-11 gives you accurate, reproducible data with m a x i m u m operating flexibility. It features expanded dynamic range for fully u n a t t e n d e d operation in a wider range of applications — in gas c h r o m a t o g r a p h y , spectrophotometry, amino acid analysis, and other analytical techniques.
Outstanding FeaturesCRS-1I CRS-11 CRS-11 CRS-11 CRS-11
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CRS-11 · CRS-11 · CRS-11 · CRS-11 · CRS-11 ·
Expanded dynamic range, unattended operation Printed listings of peak areas and retention times Computer compatible output available Fully automatic peak sensing Wider range of applications — from ionization detection (capillary column chromatography) to amino acid analysis Adaptable to process as well as laboratory operation Unexcelled accuracy, resolution and reproducibility Proved solid-state, plug-in circuitry insures trouble-free performance Operates from standard 50-60 cps power lines Automatic baseline correction and stabilization accessory
For a CRS-11 demonstration on your analysis problems, for CRS-11 specifications and application data, c o n t a c t . . .
INFOTRONICS 1401 SOUTH POST OAK ROAD /
Circle No. 143 on Readers' Service Card
32 A
•
ANALYTICAL CHEMISTRY
CORP.
HOUSTON, TEXAS 77027
Amperometric setup is used to follow reaction of uric acid with the enzyme, uricase, by chemist at the University of Maryland. The reaction forms hy drogen peroxide which reacts with iodide ion to form iodine. The for mation of iodine is followed amperometrically, and the concentration of reacted uric acid is calculated from the amount of iodine formed catalytic wave. For cysteine con centrations between 2 χ 10 7 Μ and 10~3M in O.liVf ammonia—ammo nium chloride, the catalytic current was proportional to the surface area of the mercury drop. The currents were not proportional to the con centration of the divalent cobalt. Miiller and Davis (23) suggested t h a t the only suitable method for reporting these data was to plot the current density vs. the molar con centration of cysteine. For pro teins, the method of reporting is a plot of current density vs. the loga rithm of the protein concentration in grams per 100 ml. I t is only through the use of master curves prepared in this way t h a t the data of different workers can be com pared. Cancer Diagnosis with the Protein Double W a v e
A further study of the catalytic cysteine wave and of proteins which on hydrolysis yielded either cys teine or cystine hydrolysates, led to an interesting discovery. There was a difference in the n a t u r e of the double wave for sera of normal and cancer patients (5). These differ ences could be exaggerated by denaturation of the proteins with po tassium hydroxide or by peptic di gestion or by t r e a t m e n t with sul-
