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目的采用超高效液相色谱-串联质谱法(UPLC-MS/MS),对腌制食品中敌敌畏和敌百虫的前处理方法进行研究。方法样品用含0.1%甲酸的乙腈溶液超声提取后,分别经分散固相萃取(d-SPE)或凝胶渗透色谱(GPC)净化;采用BEH C18色谱分离柱,以乙腈-0.1%甲酸水溶液梯度洗脱,正离子多反应监测模式测定,外标法定量。结果敌敌畏和敌百虫在一定浓度范围内呈良好线性,r均>0.999。d-SPE净化方法对敌敌畏和敌百虫的检出限均为1.0μg/kg,定量限为2.0μg/kg;而GPC净化方法的检出限和定量限分别为0.5和1.0μg/kg。以空白样品(选取火腿和腊肉为代表性基质)进行2、10、20和40μg/kg水平的加标回收试验,d-SPE和GPC两种净化方法对敌敌畏和敌百虫的平均回收率均分别在81.7%~104.2%之间和72.4%~89.8%之间,RSD均<7.8%。采用dSPE和GPC两种净化方法对阳性样品的测定结果无明显差异。结论本方法快速、准确、灵敏度高,适用于火腿和腊肉等腌制食品中非法添加敌敌畏和敌百虫的监测。对采集的8份火腿、腊肉和咸鱼干样品进行检测,1份火腿样品检出痕量敌敌畏。
OBJECTIVE To study the pretreatment methods of dichlorvos and trichlorfon in preserved food by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS / MS). Methods The samples were eluted with acetonitrile containing 0.1% formic acid and then purified by dispersive solid-phase extraction (d-SPE) or gel permeation chromatography (GPC). The separation was performed on a BEH C18 column with a gradient of acetonitrile-0.1% formic acid Elution, positive ion multi-reaction monitoring mode determination, external standard method. Results dichlorvos and trichlorfon in a certain concentration range was linear, r> 0.999. The detection limits of dichlorvos and trichlorfon were both 1.0μg / kg and 2.0μg / kg for d-SPE purification method, while the detection limits and the limits of quantitation of GPC method were 0.5 and 1.0μg / kg, respectively. The spiked recoveries of 2, 10, 20 and 40 μg / kg were determined by blank samples (representative ham and bacon were selected). The average recoveries of dichlorvos and trichlorfon by d-SPE and GPC Respectively, between 81.7% and 104.2% and between 72.4% and 89.8% with RSD <7.8%. There was no significant difference between the two methods of dSPE and GPC in the determination of positive samples. Conclusion The method is rapid, accurate and sensitive. It is suitable for the monitoring of illegally added dichlorvos and trichlorfon in pickled foods such as ham and bacon. Eight samples of dried ham, bacon and dried salted fish were collected and one of the ham samples was tested for trace levels of dichlorvos.