Comparison of extraction methods for methamphetamine and its metabolites in tissue

Five extraction methods were examined for analysis of methamphetamine and its major metabolites in tissue samples. The extraction methods studied were an acetone extraction method, an ethanol extraction method, an ammonium sulfate method, dialysis, and a direct solvent extraction. Acetone, ethanol, and dialysis methods showed no interference from endogenous components using thin-layer chromatography and gas chromatography, and gave satisfactory recovery of methamphetamine, amphetamine, and p-hydroxymethamphetamine when added to rabbit liver. These methods, however, proved time-consuming. The ammonium sulfate method and direct solvent extraction method were simple and more rapid, but recovery of the polar metabolite was poor.