1,1'-[ethenylidenebis(sulfonyl)]bis-benzene: A useful pre-chromatographic derivatization reagent for HPLC analyses of thiol drugs

The use of 1,1'-[ethenylidenebis(sulfonyl)]bis-benzene as a pre-chromatographic reagent for LC analysis of thiol drugs is proposed. The reagent reacts rapidly (2 min) under mild conditions (pH 7.5, ambient) with thiol drugs and the resulting adducts can be chromatographed under reversed-phase conditions (C-18 column). Excess reagent can be removed from the reaction mixture by simple liquid-liquid extraction with chloroform. The HPLC method using UV detection was successfully applied to the analysis of reduced glutathione (GSH), N-acetylcysteine, N-2-mercaptopropionylglycine and captopril in their commercial formulations.