Hutchinson M J, Young P B, Kennedy D G
Queen's University Belfast, Department of Veterinary Science, Belfast, UK.
J Chromatogr B Analyt Technol Biomed Life Sci. 2005 Feb 25;816(1-2):15-20. doi: 10.1016/j.jchromb.2004.09.024.
A method is described for the quantitative determination of quinoxaline-2-carboxylic acid (QCA) and methyl-3-quinoxaline-2-carboxylic acid (MQCA), the metabolites that have been designated as the marker residues for the veterinary drugs, carbadox and olaquindox, respectively, in swine tissue. The method is suitable for use as a confirmatory method under EU National Surveillance Schemes. Porcine liver samples were subjected to protease digestion followed by liquid-liquid extraction. Further clean-up was performed by automated solid phase extraction (SPE) and was followed by a final liquid-liquid extraction step. Analysis was performed using a narrow bore column HPLC coupled to electrospray MS/MS, operated in positive ion mode. MS/MS product ions were monitored at m/z 102 and 75 amu for QCA, m/z 145 and 102 amu for MQCA and at m/z 106 and 152 amu for the d(4)-QCA and d(7)-MQCA internal standards, respectively. The method has been validated at 3.0, 10, 50 and 150 microg kg(-1) for both metabolites. The method performance characteristics-the decision limit (CCalpha) and the detection capability (CCbeta) have been determined for QCA at 0.4 and 1.2 microg kg(-1), respectively, and for MQCA at 0.7 and 3.6 microg kg(-1), respectively.
本文描述了一种定量测定猪组织中喹喔啉 -2- 羧酸（QCA）和甲基 -3- 喹喔啉 -2- 羧酸（MQCA）的方法，这两种代谢物分别被指定为兽药卡巴氧和喹乙醇的标记残留。该方法适用于欧盟国家监测计划下的确证方法。猪肝脏样品先进行蛋白酶消化，然后进行液 - 液萃取。通过自动固相萃取（SPE）进一步净化，随后进行最后的液 - 液萃取步骤。使用窄径柱HPLC与电喷雾MS/MS联用进行分析，以正离子模式运行。分别监测QCA的m/z 102和75 amu、MQCA的m/z 145和102 amu以及d(4)-QCA和d(7)-MQCA内标的m/z 106和152 amu的MS/MS产物离子。该方法已针对两种代谢物在3.0、10、50和150 μg kg(-1)水平进行了验证。已分别测定了QCA在0.4和1.2 μg kg(-1)以及MQCA在0.7和3.6 μg kg(-1)时的方法性能特征——决策限（CCalpha）和检测能力（CCbeta）。
