A high-throughput LC-MS/MS method for the quantitation of posaconazole in human plasma: Implementing fused core silica liquid chromatography

A rapid and robust liquid chromatographic tandem mass spectrometric (LC-MS/MS) method for the determination of posaconazole concentrations in human plasma was validated. Posaconazole was extracted from human plasma using mixed-mode cation exchange solid phase extraction in a 96-well plate format followed by gradient separation on a fused-core Halo C18 column. The analyte and its corresponding internal standard were detected using a Sciex API 4000 triple quadrupole LC-MS/MS system equipped with a TurboIonSpray™ ionization source operated in the positive ion mode. The calibration range of the method was 5.00-5000 ng/mL using a 50 μL aliquot of plasma. The assay inter-run accuracy and precision were-4.6-2.8% and 2.3-8.7%, respectively (n = 18). The results from method validation indicate the method to be sensitive, selective, accurate, and reproducible. The method was successfully applied to the routine analysis of clinical samples with the fused-core silica columns providing excellent reproducibility for greater than 1000 injections per column.