SIMULTANEOUS DETECTION OF COCAINE AND HEROIN METABOLITES IN URINE BY SOLID-PHASE EXTRACTION AND GAS-CHROMATOGRAPHY MASS-SPECTROMETRY

The present paper reports a method for the simultaneous extraction of cocaine, heroin and their metabolites from small amounts of urine (0.5 ml), using deuterated internal standards. Solid-phase extraction (SPE) on C-18 columns followed by chromatographic separation coupled with mass spectrometry allowed the detection of all the substances after their derivatization. Mass spectrometry was performed in the electron-impact selected-ion monitoring (EI-SIM) mode. The limit of detection was found to be as low as 50 ng/ml for all the analytes; for reproducibility the C.V. was always better than 7%; the method was found to be linear with correlation coefficients between 0.989 and 1.00.