Diacetylmorphine and its metabolites in plasma by HPLC with diode-array and atmospheric pressure ionization mass spectrometric detection

Based on reversed phase high performance liquid chromatography with gradien t elution and diode-array detection (HPLC-DAD) a specific and sensitive ass ay for the quantitation of diacetylmorphine (heroin, DAM) and its primary a nd secondary metabolites 6-acetylmorphine, morphine, morphine-3-beta-D-gluc uronide, morphine-6-beta-D-glucuronide and nor-morphine in plasma was devel oped. Confirmation of the peak assignment was performed by atmospheric pres sure ionization-mass spectrometry (API-MS). Plasma samples were extracted o n C-18 ODS-2 columns using an automated solid-phase extraction (SPE) unit. The recovery was between 45 and 68%. The quantitation limit of DAM and its metabolites was 50 and 10 ng/mL, resp ectively. The inter-day precision was in the range of 4.0 to 17.6%. The des cribed method was applied for pharmacokinetic studies which were part of th e evaluation and validation of DAM preparations used within a heroin-assist ed treatment program for dependent drug users.