Evaluation of a method for simultaneous quantification of codeine, dihydrocodeine, morphine, and 6-monoacetylmorphine in serum, blood, and postmortem blood.

A solid-phase extraction and gas chromatographic-mass spectrometric method for the simultaneous determination of codeine, dihydrocodeine, morphine, and 6-monoacetylmorphine in serum, blood or postmortem blood is described. The extraction technique allows the determination of free or total morphine (morphine plus morphine glucuronide). Experiments with spiked blood samples resulted in recoveries of 96.4% +/- 4.2% for codeine, 95.8% +/- 5.1% for dihydrocodeine, 90.3% +/- 7.8% for 6-monoacetylmorphine and 92.5% +/- 8.1% for morphine. Excellent linearity was obtained over the range 1-1500 ng/mL. The detection limit for all analytes is less than 1 ng/mL.