HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC SEPARATION OF PENICILLAMINE ENANTIOMERS LABELED WITH N-[4-(6-DIMETHYLAMINO-2-BENZOFURANYL)PHENYL]MALEIMIDE ON A CHIRAL STATIONARY-PHASE

Penicillamine enantiomers derivatized with N-[4-(6-dimethylamino-2-benzofuranyl)phenyl]maleimide (DBPM) were separated and determined by high-performance liquid chromatography, A fluorogenic reagent, DBPM easily reacted with D- or L-penicillamine to give each two kinds of strong fluorescent derivatives (D-1-, D-2-, L(1)- and L(2)-DBPM), which could be separated on a Pirkle-type chiral stationary phase using an eluent of 75% aqueous methanol solution containing 0.15 M CH3COONH4 and 0.05 M tetra-n-butylammonium bromide. Two of the peaks (D-1- or L(1)-DBPM), having a shorter retention time than the others, had almost the same retention times (25 min for D-1-DBPM and 25.7 min for L(1)-DBPM), The retention times of the peaks eluted later were 28 min and 31.6 min for D-2- and L(2)-DBPM respectively, Linear calibration curves over the range of 2-50 pmol per injection were obtained for D- and L-penicillamines with a detection Limit of 290 and 350 fmol at respectively at a signal-to-noise ratio of 3, Using the proposed method, the absence of contamination of L-penicillamine in a commercially available D-penicillamine preparation (capsule) was confirmed.