High throughput analysis of vancomycin in human plasma by UHPLC-MS/MS.

An analytical assay based on ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) technique for absolute quantification of vancomycin in complexed biological matrix was developed in this study. Reversed phase column with gradient elution was chosen for chromatographic separation of vancomycin and internal standard (IS) norancomycin. Sample pretreatment was performed by micro-solid phase extraction (μ-SPE) with Oasis® MAX μElution Plate (I.D., 30 μm). Multiple reaction monitoring (MRM) transition was chosen for monitoring of the analytes. For vancomycin, mass-to-charge ratio (m/z) of the MRM transition was 725.3→144.1; For norvancomycin, m/z of the MRM transition was 718.3→144.2. The running time was 3 minutes for each sample. The UHPLC-MS/MS method showed a good linear relationship (R≥0.995) in the concentration range of 0.5-100 μg/mL. The intra- and inter-day accuracies (relative error, RE) are within the range of -3.44 %-1.50 % and precisions are between 3.48 % and 10.19 %. μ-SPE could enrich the analytes and decrease the endogenous interferences, thereby improving the selectivity and sensitivity of the method. The analytical assay is selective, accurate and reproducible. The assay was successfully applied to therapeutic drug monitoring of vancomycin in clinical application.