Determination of Codeine, Morphine and 6-Acetylmorphine in Urine

DONG-LIANG LIN^1,2, KAI-PING SHAW³ AND CHAU-YANG CHEN¹

1. Graduate Institute of Pharmaceutical Sciences, Taipei Medical College, Taipei, Taiwan, R.O.C.
2. Scientific and Technical Research Center, Ministry of Justice Investigation Bureau, P.O. Box 3562, Taipei, Taiwan, R.O.C.
3. Dept. Biology & Anatomy, National Defense Medical Center, Taipei, Taiwan, R.O.C.

ABSTRACT

   A simple yet effective GC/MS protocol was developed and evaluated for the determination of free codeine, free morphine, 6-acetylmorphine, total codeine and total morphine in urine. Optimal recovery was achieved with extraction conducted at pH 9.0. Trimethylsilyl-derivatives of these analytes and the internal standard (nalorphine) were found adequately stable for a 72-hour period. Quantitative determination of the analytes was performed by selective ion monitoring. Excellent linearity was observed over the 50-1000 ng/mL concentration range studied. The intraday and interday precisions range from 0.47 to 7.72% for codeine, 0.31 to 8.09% for morphine and 0.49 to 6.15% for 6-acetylmorphine. The overall recoveries for codeine, morphine and 6-acetylmorphine were found to be 98.3%, 76.7% and 85.6% respectively.

Key words : GC/MS Quantitation, morphine, codeine, 6-acetylmorphine, urine