HPLC-UV determination of morphine in human plasma and its application to the clinical study.

A sensitive and specific high-performance liquid chromatography method with ultraviolet detection (HPLC-UV) has been developed for the quantification of morphine sulfate [(5alpha,6alpha)-7,8-didehydro-4,5-epoxy-17-methylmorphinan-3,6-diol], (CAS: 52-26-6) in human plasma. The analyte was extracted from plasma samples with chloroform - isopropyl alcohol (90:10, v/v) and analyzed on a Bondapak C18 column. The calibration curves were linear within the range of 10-150 ng/mL. The lower limit of quantitation was 10 ng/mL with 0.5 mL plasma sample. The mean recovery of the drug from plasma samples was 83.39%. The results from analysis of quality-control samples at concentrations of 30, 75, and 150 ng/mL were indicative of good accuracy and precision. This method was successfully used to analyze morphine in plasma samples of patients after abdominal hysterectomy.