CONTRIBUTION OF THE LIPOPHILIC BUFFER TO CHIRAL RECOGNITION UNDER REVERSED-PHASE CONDITIONS

A lipophilic buffered aqueous mobile phase, without organic modifier, was used for the high performance liquid chromatographic enantiosepara tion of D,L-lactic acid on a Merck ChiraSpher (250 mm x 4 mm i.d.) col umn in which the chiral selector is poly(N-acryloyl-S-phenylalanine et hyl ester) bonded to a spherical silica particle. The lipophilicity of the buffer was achieved by addition of triethylammonium phosphate, th e 'ethyl' apolar chains of which dynamically modified the ChiraSpher s tationary phase and increased its hydrophobic character. The ion-paire d (cethyltrimethylammonium bromide) anaIyte enantioseparation was real ized by hydrogen-bonding and dipole-dipole complexation on the ChiraSp her stationary phase, superimposed on simultaneous reversed-phase part itioning.