Simple and rapid determination of norethindrone in human plasma by supported liquid extraction and ultra performance liquid chromatography with tandem mass spectrometry

We report for the first time an ultra performance liquid chromatographic method with tandem mass spectrometric detection (UPLC/MS/MS) for the determination of norethindrone alone in human plasma over the concentration range of 50.0–25 000 pg mL−1 using a sample volume of 0.250 mL. Norethindrone and its internal standard (ISTD), norethindrone-13C2, were extracted from human plasma by supported liquid extraction (SLE). After evaporation of the organic solvent, samples were reconstituted and analyzed on an UPLC/MS/MS system. The UPLC system used a Waters BEH C18 (100 mm × 2.1 mm, 1.7 μm) column with mobile phase A of 0.05% formic acid in water:acetonitrile (65:35, v/v) and mobile phase B of 0.05% formic acid in methanol:acetonitrile (50:50, v/v). The flow rate was 0.500 mL min−1. The method was fully validated. The inter-run accuracy and precision at the lower limit of quantitation (LLOQ), low, mid and high quality control (QC) concentration levels were 99.2–108.4% with a <8.1% CV (coefficient of variation), respectively. The validated method has been successfully applied to analysis of thousands of pharmacokinetic samples.