For High Performance in Steroid and Pesticide GLC ChromosorB HP in both Chromosorb Wand G acid washed
AUTO-SPENSER®
DMCS treated grades
Figure 1—Company A. Support acid a n d base washed, v a c u u m siliconized, 8 0 / 9 0 m e s h .
CHOLESTEROL
CHOLESTAN -3-ONE
AUTODILUTOR®
How precisely are you pipetting and diluting?
Figure 2—Company B. Support acid washed. DMCS t r e a t e d , 8 0 / 1 0 0 m e s h . This is Company B's l a t e s t i m p r o v e d v e r s i o n f o r s t e r o i d , a l k a loids, bile acids, pesticides, etc.
T h e A U T O - S P E N S E R ® is a precision pipetter. The A U T O DILUTOR® is a precision dilutor. Both instruments are faster, easier to use, safer and more accurate than glassware devices. Isn't this a better way to obtain reliable information? For specifications on these two versa tile instruments, see your favorite distributor salesman or write directly to us.
We spent a long time perfecting Chromo sorb* HP to meet critical performance re quirements. But quality development can't be rushed. Chromosorb HP (High Performance) grades are available now in 80/100 and 100/120 mesh in standard reagent bot tles and in the popular large bulk carton (10 lbs. for Chromosorb W, 25 lbs. for Chromosorb G) for central storeroom re quirements. And we'll fill your orders without delay through the worldwide network of J-M dealers.
AO INSTRUMENT COMPANY
glass " U " tube. All coated with 3 % SE-30 and conditioned at 2 3 0 ° C f o r 6 0 minutes, flow 60 m l / m i n . Same operating condi-
CONDITIONS: All columns 4 ft. χ 3 mm ID
Analytical
Instrument
Division
200 South Carrard Blvd. • Richmond, California, U.S.A. 94604 A Division of American Optical Corporation
Circle No. 18 on Readers' Service Card
Figure 3—Johns-Manville. H.P. Chromosorb W, AW-DMCS, 8 0 / 1 0 0 m e s h .
tions. Sample: 1 microliter toluene con taining 1 microgram each of cholesterol and cholestan-3-one. COMMENTS: Figure 1—The highly sensitive cholesterol is dehydrated and seen as a tailing peak. The cholestan-3-one seen much later as a severely tailing peak. Fig ure 2—Part of the cholesterol is lost, as indicated by the smaller peak. Figure 3— Chromosorb W gives two distinct peaks with no tailing, no loss. For more information about Chromo sorb HP, write for Technical Bulletin FF149, Johns-Manville, Box 325, New York, New York 10016. Cable address: Β ^ ΐ Johnmanvil. Ztiil
Johns-Manville
* C H R O M O S O R B is a Johns-Manville registered trademark for its brand c f prod ucts developed for use as support material or absorbents for gas chromatography. Circle No. 60 on Readers' Service Card
VOL. 40, NO. 0, MAY 1968 ·
151 A
