COSMOSIL C22-AR-II, C8-MS, C4-MS, TMS-MS, PE-MS

COSMOSIL alkyl type columns also include stationary phases with packing materials of C22 (Dococyl group), C8 (Octadecyl group), C4(Butyl group) and TMS (Trimethyl group). The order of retention force by hydrophobicity of each packing material is C22=C18>C8>C4>TMS. The columns having lower hydrophobicity than C18 or C22 are effective for separation of high hydrophobic compounds and compounds with big difference in hydrophobic. Hydrophobicity of C22 is about the same as C18. However, stere-oselectivity of C22 is higher than C18, and so C22 may provide better separation.

COSMOSIL Alkyl Type HPLC Columns
	C22-AR-II	C8-MS	C4-MS	TMS-MS
Structure
Base Material	Spherical Silica Gel
Particle Sizes Available	5um
Pore Size	120A
Surface Area	300m2/g
pH Range	2.0 - 8.0
USP Code	-	L7	L26	L13
Carbon Load	19%	10%	7%	5%

Effect of Alkyl Chain Length on Reversed Phase

The shorter alkyl chain stationary phase shows shorter retention time for non-polar compounds such as benzene and toluene and longer retention for polar compounds such as acetophenone and benzoate.

Ordering Information