QuEChERS-超高效液相色谱-串联质谱法测定动物源食品中痕量五氯酚及其钠盐

采用改良的QuEChERS-超高效液相色谱-串联质谱（UPLC-MS/MS）技术，建立了动物源食品中痕量五氯酚及其钠盐的测定方法。样品中五氯酚钠在酸性条件下转化为五氯酚，采用1%（v/v）乙酸乙腈超声提取2次，提取液浓缩后分散固相萃取净化，以回收率及基质效应为考察指标，对吸附剂进行了优化。采用Waters Acquity UPLC HSS T3色谱柱梯度洗脱分离，在电喷雾电离（ESI）源、负离子模式和多反应监测模式下检测，基质匹配外标法定量。在1.0、2.0、10.0 μg/kg添加水平下6种基质（猪肉、猪肝、鸡肉、鱼肉、牛奶、鸡蛋）中五氯酚的加标回收率为73.2%~108.4%，相对标准偏差为4.0%~14.8%；定量限（S/N>10）为1.0 μg/kg。该方法简便、灵敏、准确、环保，适用于动物源食品中痕量五氯酚及其钠盐残留的定性定量分析。

Determination of trace pentachlorophenol and its sodium salt in animal-origin foods by QuEChERS-ultra performance liquid chromatography-tandem mass spectrometry

A method was developed for the determination of trace pentachlorophenol and its sodium salt in animal-origin foods by modified QuEChERS-ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Sodium pentachlorophenolate in samples was converted to pentachlorophenol under acidic condition. The pentachlorophenol was extracted twice with acetonitrile containing 1% (v/v) acetic acid by ultrasonic extraction. The extracts were purified by dispersive solid-phase extraction. The usages of dispersive sorbents were optimized based on the recoveries and matrix effects. Chromatographic analysis was conducted on a Waters Acquity UPLC HSS T3 column with gradient elution. The pentachlorophenol was further analyzed by negative electrospray ionization under the multiple reaction monitoring mode. The recoveries at fortification levels of 1.0, 2.0 and 10.0 μg/kg in six matrices (pork, pork liver, chicken, fish, milk and egg) ranged from 73.2% to 108.4% with the relative standard deviations of 4.0%-14.8%. The limits of quantification (S/N>10) were 1.0 μg/kg. The method is simple, sensitive, accurate, economical and environmentally safe, and is suitable for the determination of the trace pentachlorophenol and its sodium salt in animal-origin foods.