超高效液相色谱-串联质谱法测定牛肉中9种头孢菌素类药物残留

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)测定牛肉中9种头孢菌素类药物残留的方法。头孢菌素类药物经乙腈-水溶液提取,Oasis HLB柱净化。以乙腈-水(含0.05%甲酸)为流动相,UPLC-MS/MS法测定。结果表明,9种头孢菌素类抗生素在5 min内达到分离。头孢呋辛的定量限为10 μg/kg,头孢洛宁和头孢噻夫的定量限为0.5 μg/kg,其他头孢菌素的定量限均为1.0 μg/kg。加标回收率为74.2%～119%,精密度(RSD)≤15%。该方法简单、灵敏、可靠,适用于牛肉中头孢菌素类药物残留的分析确证。

Determination of 9 cephalosporin drug residues in beef by ultra performance liquid chromatography-tandem mass spectrometry

A confirmative method to determine 9 cephalosporin residues in beef by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed. The sample was homogenized and extracted with acetonitrile and water for 1 min at 14000 r/min, centrifuged at 10000 r/min and 4 ℃ for 10 min. A total of 2 mL saturated sodium chloride solution was added to avoid foaming during the acetonitrile evaporation, the acetonitrile was evaporated below 37 ℃ using a rotary evaporator, and then cleaned up on an Oasis HLB(500 mg, 6 mL) SPE column by washing with 5 mL water and eluting with acetonitrile-water (7:3, v/v). The eluate was blown to dryness under a stream of nitrogen and adjusted to 3.0 mL with water. The separation was carried out on an ACQUITY UPLCTM BEH C18 column within 5 min, analyzed by UPLC-MS/MS system with external standard method. The limits of quantification (LOQs) of cefuroxime, ceftiofur and cefalonium were 10, 0.5 and 0.5 μg/kg, respectively; the LOQs of other cephalosporins were 1.0 μg/kg. The recoveries of cephalosporins ranged from 74.2% to 119% and the relative standard deviations (RSDs) ranged from 2.9% to 15% for the spiked beef sample. The method is quick, easy, very sensitive and suitable for the determination of cephalosporin residues in beef.