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
VOL.
36, NO. 6, MAY 1964
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107 A
