鸡肉中硝基咪唑类药物残留量检测

利用高效液相色谱-串联质谱法测定鸡肉中硝基咪唑类药物残留。采用乙腈（含体积分数0.2%甲酸）进行样品提取，然后经过Oasis Prime HLB固相萃取小柱净化处理，目标物在液相系统进行洗脱分离，并使用质谱电喷雾电离源正离子扫描模式进行检测。结果表明：在优化所得色谱流动相条件下，4 种硝基咪唑类药物在一定质量浓度范围内（1.0～15.0 ng/mL）线性关系良好，相关系数≥0.991；在0.25、0.50、2.50 μg/kg 3 个水平的加标实验中，回收率分别为79.4%～105.8%、88.4%～104.6%、88.6%～101.3%，相应的标准偏差分别为≤11.9%、≤4.8%、≤2.8%，表明该方法准确度和精密度良好，能够满足日常快速检验的需求；4 种硝基咪唑类药物均有不同程度的基质效应，其中洛硝达唑的基质效应最明显，且同一种物质加标水平越低，基质效应越明显。

Determination of Nitroimidazole Residues in Chicken by High Performance Liquid Chromatography-Tandem Mass Spectrometry

The objective of this study was to establish and optimize a quick method for the determination of nitroimidazole residues in chicken by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The samples were extracted using 0.2% formic acid in acetonitrile, and then the extract was purified using an Oasis Prime HLB solid phase extraction column. The mass spectrometer was operated using an electrospray ionization source in the positive ion mode. Under the optimal conditions, good linear relationships were obtained for four nitroimidazoles in the concentration range of 1.0–15.0 ng/mL, with correlation coefficients no less than 0.991. The recoveries at three spiked concentration levels of 0.25, 0.50 and 2.50 μg/kg were 79.4%–105.8%, 88.4%–104.6%, 88.6%–101.3%, respectively, with relative standard deviations (RSD) equal to or less than 11.9%, 4.8%, and 2.8%, respectively. The method had good accuracy and precision, could meet the requirements for rapid detection. This method had different matrix effects for all four nitroimidazoles. The matrix effect for ronidazole was more obvious than that for the other three nitroimidazoles. The lower the spiked concentration level, the more obvious of the matrix effect for each analyte.