The use of bonded-phase extraction columns for rapid sample preparation of benzodiazepines and metabolites from serum forHPLC analysis

Abstract

A simple, rapid method for the determination of the benzodiazepines, diazepam and chlordiazepoxide, and their metabolites by high performance liquid chro-matography (HPLC) has been developed. The proce-dure is applicable to the assay of other similar drugs in biological fluids. The method utilizes BondElut ™ ex-traction columns to facilitate the extraction. BondElut columns selectively adsorb the benzodiazepines and metabolites from serum at a pH of 9.0. The compounds are eluted with 300/AI of methanol which makes sample concentration rapid, if even necessary. Analysis is per-formed using isocratic reversed-phase chromatogra-phy, and quantitation is carried out by ultraviolet (UV) detection. Using this procedure, it is possible to deter-mine drug and metabolite levels to as low as 25 ng/ml in 0.5 ml of serum