Determination of cefuroxime in human serum or plasma by liquid chromatography with electrospray tandem mass spectrometry

Cefuroxime is a second-generation cephalosporin used against different kinds of bacterial infections. To be able to optimize the dosing it is necessary to characterize the pharmacokinetics of cefuroxime which requires a selective and sensitive analytical method for cefuroxime in plasma or serum. A new rapid liquid chromatography/electrospray tandem mass spectrometry (LC/MS/MS) method, using cefotaxime as internal standard, was developed for analysis of cefuroxime in human serum. The work-up procedure consisted of protein precipitation with acetonitrile/cefotaxime, and after centrifugation the supernatant was dissolved in mobile phase. The sample was injected on a SB-CN column and the detection was performed using tandem mass spectrometry (MS/MS). The limit of quantification was determined to 0.025 microg/mL. The method was linear in the range 0.025-50 microg/mL with a coefficient of correlation >0.999. The limit of quantification and intra-day variability were found to be the same for plasma samples, which indicates that the method is valid for serum as well as plasma samples.