Determination of danazol in human plasma by liquid chromatogram-mass spectrometry

OBJECTIVE To develop a sensitive and specific LC/MS method for the determination of Danazol in human plasma. METHODS Danazol and the internal standard norethisterone were extracted with liquid-liquid extraction. The organic layer was blowed by N2 to dryness at 60℃.The residue was reconstituted in the mobile phase. The LC/MS method was performed on a Agilent Zorbax Eclipse XDB-C18(4.6 mm × 150 mm,5 μm).The mobile phase consisted of CH3OH and 0.05% HCOOH with gradient elution. The flow rate was at 1.0 mL·min-1; The temperature of column was 30℃.Atmospheric pressure chemical ionization source was applied and operated in positive mode. The ion of monitor was at m/z 338.2(danazol) and m/z 299.2(norethisterone,internal standard) .RESULTS The linear calibration curve was observed in the concentration range of 0.11 - 550 ng·mL-1. Thelower limit of quantification was 0.11 ng·mL-1. The relative recoveries were more than 90%. The inter and intra-day precision (RSD) were below 8.0% .CONCLUSION The method was proved to be convenient, sensitive, rapid and suitable for pharmacokinetic study.