Determination of Benzodiazepines in Serum by High Performance Liquid Chromatography Using Radially Compressed Columns and an Aqueous Methanolic Mobile Phase

Abstract

Diazepam, oxazepam and N-desmethyldiazepam are determined by high performance liquid chromatography using a radially compressed C18 column and an aqueous methanolic mobile phase. The chromatographic separation is completed within 10 minutes. The drugs are recovered from serum by extraction with hexane:ethyl acetate 70:30, v/v.

The method is linear in the range 50-1600 ng/ml for all the drugs, Coefficients of variation are less than 6.2% for two studied concentration levels.