Rapid and sensitive liquid chromatography–tandem mass spectrometry method for determination of 1-β-d-arabinofuranosyluracil in human plasma and application to therapeutic drug monitoring in patient with leukemia

Abstract A specific and reliable HPLC–MS/MS method was developed and validated for the determination of ara-U in human plasma. The analyte was separated on a C 18 column (50 mm × 2.1 mm, 1.7 μm) and a triple-quadrupole mass spectrometry equipped with an electrospray ionization (ESI) source was applied for detection. The plasma sample was prepared by a simple protein precipitation pretreatment and the recovery was about 80%. The calibration curves were linear over a concentration range of 1.0–7000.0 ng/mL for ara-U. The intra-day and inter-day precision was less than 15% and the relative error (RE) was all within ±15%. It was successfully applied to assess the disposition characteristics of ara-U and support the therapeutic drug monitoring after the patients with leukemia were infused with ara-C.