A Gas Chromatographic Method for the Determination of Methadone and Its Metabolites in Biological Fluids and Tissues

Abstract

A gas chromatographic procedure is presented for routine detection and quantitation of methadone and its metabolites in biological fluids and tissues. The method employs an extraction of drugs with n-butyl chloride at approximately neutral pH and chromatographic identification on 3% OV-17 using SKF-525-A and n-docosane as Internal standards. A modified extraction apparatus and the recovery of methadone, 1,5-dimethyl-3,3-diphenyl-2-ethylidene-pyrrolidine (Mbl), and SKF-525-A from a variety of fluids and tissues are described. The method is sensitive to 20 ng/ml or g and is applicable to other basic drugs.