Gas-liquid chromatographic estimation of tolbutamide and chlorpropamide in plasma

Abstract

Abstract An improved method for the gas-liquid chromatographic estimation of tolbutamide and chlorpropamide in plasma is described. The drugs are extracted into toluene, back-extracted into alkali and methylated with dimethylsulphate. The methylated derivatives are extracted into n-hexane, concentrated by evaporation and chromatographed on 3·8% UC W98 or 1% Carbowax 20M columns. The standard deviation of replicate analyses of plasma samples containing 20–100 μg/ml of either drug was about 4%. There is no interference from known metabolites of tolbutamide or chlorpropamide.