Determination of a metabolite of nifursol in foodstuffs of animal origin by liquid–liquid extraction and liquid chromatography with tandem mass spectrometry

An analytical method has been developed for the detection of a metabolite of nifursol, 3,5‐dinitrosalicylic acid hydrazide, in foodstuffs of animal origin (chicken liver, pork liver, lobster, shrimp, eel, sausage, and honey). The method combines liquid chromatography and tandem mass spectrometry with liquid–liquid extraction. Samples were hydrolyzed with hydrochloric acid and derivatized with 2‐nitrobenzaldehyde at 37°C for 16 h. The solutions of derivatives were adjusted to pH 7.0−7.5, and the metabolite was extracted with ethyl acetate. 3,5‐Dinitrosalicylic acid hydrazide determination was performed in the negative electrospray ionization method. Both isotope‐labeled internal standard and matrix‐matched calibration solutions were used to correct the matrix effects. Limits of quantification were 0.5 μg/kg for all samples. The average recoveries, measured at three concentration levels (0.5, 2.0, and 10 μg/kg) were in the range of 75.8–108.4% with relative standard deviations below 9.8%. The developed method exhibits a high sensitivity and selectivity for the routine determination and confirmation of the presence of a metabolite of nifursol in foodstuffs of animal origin.     

动物组织中硝呋索尔代谢物残留量的液相色谱串联质谱法测定

建立了动物组织中硝呋索尔代谢物二硝基水杨酸肼(DNSAH)残留量的高效液相色谱-串联质谱检测方法(HPLC-MS/MS).动物组织中的硝呋索尔代谢物在酸性条件下水解过夜,同时加入2-硝基苯甲醛进行衍生化反应,经乙酸乙酯提取浓缩,正己烷净化后.采用Thermo Hypersil Gold C18(100 mm ×2.1 mm i.d.,1.9 μm)反相色谱柱进行分离,以甲醇-水为流动相,梯度洗脱,流速为0.3 mL/min,用高效液相色谱-串联质谱仪以负离子多反应监测模式测定.结果显示,在动物组织中,DNSAH的定量下限为0.5μg/kg;线性范围为0.5～ 5.0 μg/kg,加标回收率为91％～103％,相对标准偏差为3.7％～13.6％.该方法简便、快速、准确,各项技术指标满足国内外法规的要求,适用于动物组织中硝呋索尔代谢物残留量的确证与检测.