CHROMATOGRAPHIC SURFACES PREPARED FROM LYSO PHOSPHATIDYLCHOLINE LIGANDS

A chromatographic surface was prepared by immobilizing 1-O-(11-carboxyl)undecyl-2-O-methyl-sn-3-glycerophosphocholine on silica propylamine (loading 127 mu mole/g of silica) at a monolayer density. This chromatographic surface is denoted as (ether)IAM.PC; this bonded phase is one type of immobilized artificial membrane (IAM) chromatography surface. (ether)IAM.PC was endcapped with (1) both decanoic anhydride and propionic anhydride ((ether)IAM.PCC10/C3); or (2) both dodecanoic cyclic anhydride and propionic anhydride ((ether)IAM.PCC13COOH/C3) . This latter IAM surface contains carboxyl groups at the interface of the immobilized membrane. (ether)IAM.PC columns were evaluated as liquid chromatographic supports using amphetamine analogs under isocratic conditions. After perfusing (ether)IAM.PCC13COOH/C3 with 50,000 column volumes at pH conditions between pH 2 and pH 8.5, the capacity factors, k', of amphetamine analogs on (ether)IAM.PCC13COOH/C3 column decreased only 6% of the initial value, whereas (ether)IAM.pC(C10/C3) showed this stability only at the low pH.