Diatomite supports

the support. HEXAMETHYLDISILAZANE. (HMDS) treated Chromosorb P andW: the HMDS treatment is another tech- nique to reduce surface effects of the suppor...
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F R O M JOHNS-MANVILLE

Diatomite supports for gas chromatography CHROMOSORB

J-M PRODUCTS From the very beginning of gas chro­ matography, J-M products have been used as support materials. The chromatographer can choose from a large variety of products sold under the Johns-Manville trademark, Chromosorb®. There are presently two forms or basic types of Chromosorb—Ρ and W. Both are available either treated or untreated in a number of mesh sizes. The treated products are available as acid-washed, methyl silicone coated, HMDS treated and A W-DMCS treated. The following are brief descriptions of the various grades. CHROMOSORB P: This is a calcined aggregate, pink in color and relatively hard. It is generally used as the sup­ port for the separation of hydrocar­ bons or moderately polar compounds. CHROMOSORB W: This material is a flux calcined aggregate, white in color and not as hard as Chromosorb P. Because of its comparatively inert sur­ face, it is frequently used for the sepa­ ration of polar compounds. ACID WASHED Chromosorb Ρ and Chromosorb W : The acid washing treatment is used to reduce the surface effects of the support. METHYL SILICONE COATED Chro­ mosorb Ρ and Chromosorb W : The methyl silicone coating is another tech­ nique used to reduce surface effects of the support. HEXAMETHYLEISILAZANE (HMDS) treated Chromosorb Ρ and W : the HMDS treatment is another tech­ nique to reduce surface effects of the support. J-M RESEARCH LABORATORY Johns-Manville, the largest producer of supports for gas chromatography, has expanded its efforts in gas chro­ matography. A laboratory, located at the Johns-Manville Research Center in Manville, New Jersey, is completely de­ voted to work dealing with chromato­ graphic supports. Recent additions of both personnel and equipment make an expanded program possible. Projects are under way to improve existing grades of Chromosorb by various treat­ ments as well as to develop new types

of Chromosorb. In addition, the labora­ tory serves as the source of informa­ tion for our continuing series of tech­ nical data bulletins on gas chromatog­ raphy. These new facilities make pos­ sible continued improvements in the purity and particle size distribution of the Chromosorb grades to give an even more consistently uniform product. LITERATURE AVAILABLE To keep the chromatographer informed, Johns-Manville regularly issues tech­ nical bulletins dealing with gas chro­ matography. Should you wish any of the following bulletins, fill out and mail in the coupon:

FF-101 Grades and Particle Size FF-102 Diatomite Aggregates for Gas Chromatography FF-103 Deactivation of Chromosorb Ρ and Chromosorb W FF-104 Elementary Gas Chroma­ tography FF-114 AW-DMCS Treated Sup­ ports Also, please indicate if you wish to be added to our mailing list. J-M CHROMOSORB DEALERS For your convenience, Johns-Manville has a network of dealers located from coast to coast, and in major industrial centers around the world.

Latest Chromatographic

Developments

NEW... MORE INERT CHROMATOGRAPHIC SUPPORTS AW-DMCS-TREATED CHROMOSORB Acid-washed dimethyldichlorosilane (AW-DMCS) treated Chromosorb Ρ and W are now available from yourChromosorb Dealer.The DMCS treatment, combined with acid washing, produces a surface that will cause far less tailing when used for separation of polar compounds. It's dust free so there is less pressure drop and it's uni­ form to assure greater reliability. The AW-DMCS is superior in these respects to the present grades (acid-washed, HMDS and methyl silicone treated) in many separa­ tions. As is usually the case, Chromosorb W is more inert than the P. A complete discussion of AWDMCS treated supports is availa­ ble in our technical bulletin FF-114.

5 per cent squalane on both supports t o sepa­ rate a mixture of ethanol (A), methyl ethyl ketone (B), benzene (C), and cyclohexane (D).

JOHNS-MANVILLE, BOX 325, NEW YORK 16, N.Y. Please send me the following technical bulletins : Π FF-101 Π FF-102 Π FF-103 Π FF-104 Π Please add me to your permanent Chromosorb mailing list.

Π FF-114

NAME ADDRESS CITY COUNTY

JOHNS-MANVILLE

ZONE STATE

CELITE DIVISION

Circle No. 178 on Readers' Service Card

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36, NO. 6, MAY 1964

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