MEASUREMENT OF HEROIN AND ITS METABOLITES BY ISOTOPE-DILUTION ELECTRON-IMPACT MASS-SPECTROMETRY

A solid-phase extraction procedure was developed for the isolation of heroin, 6-acetylmorphine, and morphine from blood, plasma, saliva, and urine with subsequent assay by gas chromatography/mass spectrometry. Aprotic solvents, mild elution conditions, and an enzyme inhibitor wer e used to ensure maximum analyte stability. Samples were extracted and the extract was divided into two equal portions. One portion was assa yed directly for heroin; detector response was linear over a concentra tion range of 1.0 to 250 mug/L. The second part of the extract was rea cted with N-methyl-bis-trifluoroacetamide and assayed for the trifluor oacetyl derivatives of 6-acetylmorphine and morphine; detector respons e was linear over a concentration range of 1.0 to 500 mug/L. The limit of sensitivity was 1.0 mug/L for each analyte. Hydrolysis of heroin t o 6-acetylmorphine during extraction and analysis was <5%. The method can be used to corroborate heroin use and to study the pharmacological effects of heroin and its metabolites.