SOLID-PHASE EXTRACTION OF MORPHINE AND ITS METABOLITES FROM POSTMORTEM BLOOD

A simple and rapid high-performance liquid chromatographic method is d escribed for the determination of morphine-3-glucuronide, morphine-6-g lucuronide, normorphine and morphine in postmortem blood. A solid phas e extraction technique employing C-18 Sep-Pak cartridges was used to r ecover morphine and its metabolites from 0.5 ml of blood. Reverse phas e ion-pair chromatography was used to achieve separation with a C-18 b onded column, The mobile phase consisted of acetonitrile, lauryl sulph ate and sodium dihydrogen orthophosphate buffer at low pH. Electrochem ical detection (ECD) in series with ultraviolet (UV) spectrophotometri c detection (210 nm) was used for quantitation, The lower limit of det ection using ECD was 10 ng/ml for all analytes and a linear response w as observed to 5000 ng/ml. Coefficients of variation for all analytes ranged between 3-13% for both intra- and inter-assay. This method is r eproducible, quick and easy to perform and allows morphine conjugates and morphine to be measured simultaneously in postmortem blood.