ABSTRACT
OBJECTIVE: To establish an UPLC-MS/MS method for the determination of linezolid in human plasma. METHODS: The analytical column was packed with Acquity BEH C18(2.1 mm × 50 mm, 1.7 μm, Waters). The mobile phase A consisted of water(containing 0.1% formic acid), the mobile phase B consisted of acetonitrile. The analytes were eluted from the column with a linear gradient. The flow rate was 0.4 mL · min-1. A tandem mass spectrometer equipped with electrospray ionization source was used as detector multiple reaction monitoring(MRM) using the precursor to production pairs of m/z 338.2→296.2 (for linezolid) and m/2: 237.1→-194.2(for carbamazepin) were used to quantification. RESULTS: The liner range of linezolid in human plasma was 20-20 000 μg · L (r=0.9979). The limit of detection was 20 μg · L-1. Intra-day and inter-day RSD for assaying the plasma sample of linezolid were both lower than 6.26%, absolute recovery were more than 80%. CONCLUSION: The method is proved to be highly sensitive, selective, and suitable for pharmacokinetic investigations of linezolid.