动物组织中卡巴氧和喹乙醇以及相关代谢产物的液相色谱-串联质谱检测方法

Determination of the Residues of Carbadox,Olaquindox and Related Metabolites in Bovine and Porcine Muscle and Liver Tissues by LC-MS/MS

建立了牛、猪肌肉和肝脏组织中卡巴氧（CBX）和喹乙醇（OQX）以及相关代谢产物——脱氧卡巴氧（DCBX）、喹嗯啉-2-羧酸（QCA）和3-甲基喹嗯啉-2-羧酸（MQCA）残留的LC—MS／MS的检测方法。组织样品中的卡巴氧用乙腈-乙酸乙酯（体积比1：1）溶液提取；代谢产物的提取则是经适当处理后的样品加入Protease蛋白酶进行酶解，后采用阴离子交换固相萃取柱Oasis MAX进行净化和富集。分析样品以甲酸溶液（体积分数为0．1％）-甲醇-乙腈为流动相，经Inertsil ODS-3色谱柱分离，在LC—MS／MS多反应监测模式下进行定性、定量分析，采用正离子扫描。CBX、DCBX、QCA和MQCA的定量下限均为0．5μg／kg，猪、牛肌肉和肝脏在0．5～5．0μg/kg添加水平的平均回收率在76％～97％之间，相对标准偏差（n=10）在2．9％～16．9％之间。

A liquid chromatography -tandam mass spectrometric （LC -MS/MS） method was devel- oped for the simultaneous identification and determination of residues of carbadox（CBX） , olaquindox and related metabolites, desoxycarbadox（ DCBX）, quinoxalie-2-carboxylic acid（QCA） and 3-meth- ylquinoxaline-2-carboxylic acid（MQCA） in bovine and porcine muscle and liver tissues. CBX was extracted by acetonitrile - ethyl acetate（ 1 ： 1, by volume）. As for the extraction of DCBX, QCA and MQCA, homogenized liver or muscle tissue was first digested with 0.6% formic acid to deactivate naturally-occurring enzymes. After overnight enzymatic hydrolysis with protease, the tissue extract was acidified, centrifuged and filtered. DCBX, QCA and MQCA were recovered from the tissue extract using an Oasis MAX solid phase extraction（SPE） cartridge. The analytes were separated on an Inertsil ODS-3 LC column, and determined qualitatively and quantitatively under multi-reaction monitoring（MRM） scan type with tandem mass analyzer using positive polarity mode. The limits of quatitation （LOQ） for the four analytes in bovine and porcine muscle and liver tissues were 0.5μg/kg. At the spiked level in the range of 0. 5 - 5.0 μg/kg, the mean recoveries were in the range of 76% - 97% , the relative standard deviation were in the range of 2.9%- 16. 9%.