Simultaneous Determinations of Tetracycline and beta-lactam Antibiotics in Meat by HPLC/Tandem MS

A rapid method for simultaneous determinations of 16 antibiotics (4 different tetracyclines and 12 beta-lactam antibiotics) in meat using a liquid chromatography/tandem mass spectrometry was developed. Antibiotics were extracted from meat with an EDTA-McIlvaine solution after denaturing protein with acetonitrile. The extracts were diluted, and then these were purified by solid-phase extraction (SPE). Both improvement of operability and an increase in the recoveries from spiked samples were achieved by denaturing the protein. A rapid purification by SPE was possible because the evaporation step for removing the acetonitrile from extracts became unnecessary by the step of diluting each extract. The average recovery, repeatability and reproducibility for the 16 antibiotics in each product were as follows: 86 %, 6.0 % and 8.4 % (bovine muscle); 81 %, 5.6 % and 7.8 % (bovine kidney); 83 %, 6.3 % and 7.8 % (bovine liver), respectively.