Thin-layer chromatographic separation of methadone and its primary metabolite in the presence of other drugs in urine specimens.

Three solvent systems for thin-layer chromatography have been developed for methadone and its primary metabolite (2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine). These solvent systems separate methadone and its primary metabolite, and are not interfered by other drugs of abuse in urine specimens.