COSMOSIL C18-AR-II HPLC Columns

Reversed phase Octadecyl group 

Acid Resistance
COSMOSIL 5C18-AR-II packed column features a polymeric type of C18 reversed phase material. The acidic resistance of COSMOSIL 5C18-AR-II is much improved compared with commercially available monomeric type octadecyl stationary phases. It retains high performance even in case of acidic mobile phases commonly used to separate acidic compounds and peptides.

Specifications

Packing Material	3C18-EB	C18-MS-II	C18-AR-II	C18-PAQ
USP Code	L1	L1	L1	L1
Silica Gel	High Purity Porous Spherical Silica
Average Particle Size	3 µm	3, 5, 15 µm		5, 15 µm
Average Pore Size	approx. 120 Å
Specific Surface Area	approx. 300 m2/g
Stationary Phase
	Octadecyl Group
Bonding Type	Monomeric		Polymeric
Main Interaction	Hydrophobic Interaction
End Capping Treatment	Near-perfect Treatment
Carbon Content	approx. 14.5%	approx. 16%	approx. 17%	approx. 11%
pH Range	2-10*		1.5-7.5*	2-7.5
Feature	This phase with a better end-capping treatment offers improved peak shape and separation particularly for basic compounds.	This phase is recommended for most applications but particularly effective for basic compounds.	This phase is recommended for separations requiring acidic mobile phase conditions. It also shows superior molecular shape selectivity to monomeric type C18columns.	This phase is designed to offer superior retention of polar compounds and excellent reproducibility in highly aqueous mobile phases, even in 100% aqueous.

Optimum pH range of columns based on silica gel is between 2 and 7.5.