Simultaneous determination of norethisterone and six metabolites in human plasma by capillary gas chromatography with mass-selective detection

• Published in: Journal of chromatography. B, Biomedical applications Biomedical applications, 1995-12, Vol.674 (2), p.155-165
• Main Authors: Pommier, F., Sioufi, A., Godbillon, J.
• Format: Article
• Language: English
• Subjects: Calibration; Dihydronorethisterone; Gas Chromatography-Mass Spectrometry - methods; Gas Chromatography-Mass Spectrometry - statistics & numerical data; Humans; Hydrogen-Ion Concentration; Hydrolysis; Mass Spectrometry; Norethindrone - blood; Norethisterone; Quality Control; Sensitivity and Specificity; Tetrahydronorethisterone
• ISSN: 0378-4347; 1572-6495
• DOI: 10.1016/0378-4347(95)00325-8

A method for the simultaneous determination of norethisterone (NET) and six metabolites in human plasma by capillary gas chromatography-mass-selective detection (GC-MS) is described. The compounds are determined in plasma after enzymatic hydrolysis. After addition of norgestrel as the internal standard, the compounds are extracted from plasma at pH 5 using an Extrelut column and elution with dichloromethane. After evaporation, the compounds are converted into bistrimethylsilyl derivatives which are determined by gas chromatography using a mass-selective detector at m/z 429 for the two dihydro-NET (5β-NET and 5α-NET), m/z 431 for the four tetrahydro-NET (3α,5α-NET, 3α,5β-NET, 3β,5β-NET and 3β,5α-NET), m/z 442 for NET and m/z 456 for the internal standard. The reproducibility and accuracy of the method were found suitable over the range of concentrations between 0.50 and 8 ng/ml for NET, and metabolites except for 5α-dihydro-NET (between 1 and 8 ng/ml). The method was applied to clinical samples.