Simultaneous quantification of cefuroxime and clindamycin in human lumbar anulus fibrosus, nucleus pulposus and serum via UPLC-MS/MS

Abstract Background This study aimed to develop a sensitive, accurate method for simultaneously quantifying cefuroxime and clindamycin in human serum, lumbar anulus fibrosus and nucleus pulposus. Methods Cefuroxime and clindamycin were quantified using ultra high-performance liquid chromatography-electrospray ionization tandem mass spectrometry in multiple-reaction-monitoring mode on a triple-quadrupole AB Qtrap 5500 system in positive ion mode. Internal standards were D3-cefuroxime and D3,13C-clindamycin. Samples were pretreated by precipitating total protein. Results The method showed high sensitivity and good linearity over broad calibration ranges from 100 to 100 000 ng/mL for cefuroxime and 10 to 10 000 ng/mL for clindamycin in serum, and from 10 to 10 000 ng/mL for cefuroxime and 1 to 1 000 ng/mL for clindamycin in lumbar nucleus pulposus. In all sample types, correlation coefficients were greater than 0.99, intra- and inter-day precision (relative standard deviation) was less than 15%, and accuracy (relative error) was within 14% for both analytes. This method was effective at quantifying penetration of cefuroxime and clindamycin in patients undergoing oblique lumbar interbody fusion surgery. Conclusions A very sensitive, specific method for simultaneous detection of cefuroxime and clindamycin has been developed for human lumbar anulus fibrosus, nucleus pulposus and serum samples.