Simultaneous Determination of 20 Antibiotics in Bovine Colostrum Tablet Using UHPLC-MS/MS and SPE

A rapid and simple method was developed for the simultaneous determination of 20 antibiotics in bovine colostrum tablets using ultra-high-performance liquid chromatography-tandem mass spectrometry. The samples were prepared by a two-step extraction procedure followed by loading onto a reversed phase HLB cartridge for purification. The matrix-matched standard curves were used to compensate the matrix effects. Linearity was achieved for the analytes in the concentration ranges studied. The limits of detection (LODs) and limits of quantification (LOQs) for all samples were 0.05-2.03 and 0.16-6.78 mu g kg(-1), respectively. The mean recoveries were from 81.3 to 113.9% at three spiked levels, the relative standard deviations (RSDs, n = 6) ranged from 0.5 to 12.6%. The developed method has been successfully applied to detecting antibiotics in real samples; clindamycin, roxithromycin, oleandomycin and ofloxacin were detected.