A rapid and sensitive gas chromatographic analysis of methadone and its primary metabolite

: A method for identification and quantification of methadone and its primary metabolite (1,5-dimethyl-3,3-diphenyl-2-2-ethylidene pyrrolidine) in plasma by GC/NPD is presented. The procedure employs SKF 525 A as the internal standard and requires no derivatization. After a single-step extraction, analysis is achieved in 10 min. The limit of detection was found to be 2 an 3 ng/ml for methadone and its metabolite, respectively. This method appears to be rapid, sensitive and applicable to forensic and clinical toxicological analyses.