Evaluation of column extraction: a new procedure for the analysis of drugs in body fluids.

A method is described for the extraction of drugs from body fluids, whereby liquid-liquid extraction is replaced by liquid-solid elution. The aqueous sample is absorbed on a column filled with dry supporting material. By elution with organic solvents lipophilic substances are extracted from the water phase which remains on the column. The eluate containing the drugs is free of emulsions. For optimal extraction any pH value and a variety of solvents can be used. Column extraction of urine, serum and blood is easily performed and gives high recovery rates, which are superior to conventional extraction. Thin layer chromatography of drugs following conventional XAD-2 and column extraction, demonstrates identical qualitative results, but shows higher purity of the column extracts. The sensitivity of detection is enhanced.