采用同位素稀释法结合固相萃取净化技术，建立了准确、灵敏的肉粉样品中5种硝基呋喃类药物的代谢物的液相色谱-串联三重四极杆质谱检测方法。样品中添加同位素内标，经盐酸水解，2-硝基苯甲醛衍生，乙酸乙酯提取，HLB固相萃取小柱净化，采用C18色谱柱分离，乙腈-甲酸铵溶液为流动相进行梯度洗脱，串联质谱ESI正负离子切换模式电离，多反应监测（MRM）模式检测。结果表明，5种硝基呋喃类药物的代谢物在各自的线性范围内线性关系良好，相关系数均大于0.9990；方法的检出限为0.05 μg/kg~0.2 μg/kg；在低、中、高3个添加水平，平均回收率（n=6）为80.33~103.24%，日内精密度在4.60~9.85%；添加水平为0.5 μg/kg时，日间精密度（n=5）小于10.3%。本方法净化效果好，灵敏度高、准确性好，适用于基质复杂的肉粉样品中5种硝基呋喃类药物的代谢物的测定。

A method for the simultaneous determination of five nitrofuran metabolites in meat meal by liquid chromatography tandem mass spectrometry (LC-MS/MS) was established, based on isotope dilution and solid phase extraction (SPE). The homogenized sample was spiked with isotope inter standards, hydrolyzed with HCl, derivatized with nitrobenzaldehyde, extracted with ethyl acetate, and cleaned up with HLB solid phase extraction cartridge. The analysis was carried out on C18 column by gradient elution with acetonitrile – ammonium acetate as mobile phase, and detected by MS/MS system with switch positive and negative electrospray ionization under multiple reaction monitoring (MRM) mode. The compounds was identified with retention time and ion ratio and quantified by the internal standard calibration curve of isotope dilution technique. The results showed that the high correlation coefficients (r>0.9990) of five targets were obtained within their respective linear ranges over dynamic range of 0.2~20 μg/L and the limits of detection (LOD, S/N=3) of five analytes were in the range of 0.05~0.2 μg/kg. The average recoveries were ranged from 80.33% to 103.24% for the five targets at three spiked levels with the relative standard deviations (RSD, n=6) were between 4.60% and 9.85%, and the inter-day RSD (n=5) was less than 10.3% at spiked levels of 0.5 μg/kg. The method was precise and sensitivity, suitable for quantitative and qualitative analysis of five nitrofuran metabolites in meat meal.

广东省自然科学基金资助项目（S2011040004201）