SOLID-PHASE EXTRACTION OF MORPHINE FROM WHOLE-BLOOD BY MEANS OF BOND ELUT CERTIFY COLUMNS

The use of Bond Elut Certify columns for the isolation of morphine fro m whole blood was evaluated. In order to monitor possible losses and t he elution profile of morphine, a small amount of the tritiated analog ue was added to the samples. Four sample pretreatment methods, three p rotein precipitation methods and one sonication/dilution method, were tested. The latter one gave the best results. The blood sample was app lied onto the column at pH 3.3 after sonication and dilution with 0.1 M phosphate buffer (pH 3.3). The retention of morphine was affected by the pH of the samples, and the loss of morphine during sample applica tion was minimized at low pH (3.3). The interferences were removed by washing the column with the phosphate buffer, 0.01 M acetic acid (pH 3 .3), and methanol, sequentially. Ammoniated methanol, 2 mL at 2%, was selected to clute morphine. As a result, more than 80% of H-3-morphine was recovered for concentrations of morphine ranging from 5 to 4000 n g/mL.