Abstract

In this study, a new quantitative analytical method has been developed for the rapid determination of vancomycin in human plasma and urine using liquid chromatography/tandem mass spectrometry (LC - MS/MS). Chromatography was carried out on a <TEX>$C_{18}$</TEX> XTerra MS column (<TEX>$2.1{\times}30mm$</TEX>) with a particle size of <TEX>$3.5{\mu}m$</TEX>. The mobile phase was 0.25% formic acid in 10% acetonitrile and the flow rate was <TEX>$250{\mu}L/min$</TEX>. Vancomycin and caffeine (internal standard) were detected by MS/MS using multiple reaction monitoring (MRM). Vancomycin gives a predominant doubly protonated precursor molecule (<TEX>$[M+2H]^{2+}$</TEX>) at m/z 725.0 and a corresponding product ion of m/z 100.0. Detection of vancomycin was good, accurate and precise, with a limit of detection of 1 nM in plasma. The calibration curves for vancomycin in human plasma was linear in a concentration range of <TEX>$0.01{\mu}M$</TEX> - <TEX>$100{\mu}M$</TEX> for plasma. This method has been successfully applied to determine the concentration of vancomycin in human plasma and urine from pharmacokinetic study and relative studies.