高效液相色谱-串联质谱法测定植物源食品中特丁硫磷、特丁硫磷砜和特丁硫磷亚砜的残留量

目的建立高效液相色谱-串联质谱法测定植物源食品中特丁硫磷、特丁硫磷砜和特丁硫磷亚砜残留量的分析方法。方法样品采用乙腈或1%乙酸-乙腈提取,提取液经分散固相萃取净化。以CORTECSC18(100 mm×2.1 mm, 2.7mm)色谱柱分离待测物,以0.1%乙酸铵甲醇溶液和0.1%甲酸加乙酸铵水溶液为流动相,梯度洗脱,流速为0.3m L/min,柱温35℃。目标化合物采用电喷雾正离子电离、多反应监测模式检测,以基质匹配校准曲线外标法进行定量分析。结果 3种化合物的相关系数均大于0.997, 3种化合物的检测定量限均低于0.005 mg/kg。3种化合物在10种基质(柑橘、苹果、大葱、黄瓜、西兰花、菠菜、胡萝卜、花生、大米、茶叶)中3个添加水平(0.005、0.01、0.05 mg/kg)的回收率为79.2%~105%,相对标准偏差为1.2%~20.1%。结论该方法简便、灵敏、环保,回收率和精密度好,适合于植物源食品中特丁硫磷及其氧类似物(砜、亚砜)残留的检测。

Determination of terbufos, terbufos-sulfone and terbufos-sulfoxide residues in plant origin foodstuffs by high performance liquid chromatography-tandem mass spectrometry

Objective To establish a method for the determination of terbufos, terbufos-sulfone and terbufos-sulfoxide residues in plant-based foods by high performance liquid chromatography-tandem mass spectrometry. Methods The samples were extracted with acetonitrile or acetonitrile containing 1% acetic acid, the extracts were cleaned up by dispersive solid phase extraction, and separated by CORTECS C18(100 mm×2.1 mm, 2.7 mm) column using 0.1% ammonium acetate in methanol and 0.1% formate + ammonium acetate as mobile phase at the flow of 0.3 m L/min by gradient elute, and the column temperature was maintained at 35 ℃. Target compounds were analyzed by positive electrospray ionization tandem mass spectrometry under multiple reaction monitoringmode. Quantification was achieved using matrix-matched standard calibrations as the external standard. Results The correlation coefficients of the 3 compounds were all greater than 0.997, and the limits of quantitation were lower than 0.005 mg/kg. Recoveries of 3 compounds in 10 matrixes(mandarin, apple, shallot, cucumber, brocolli, spinach, carrot, peanut, rice and tea) at fortification levels of 0.005, 0.01, 0.05 mg/kg ranged from 79.2% to 105%, and relative standard deviations(RSDs) were 1.2%-20.1%. Conclusion This method is simple, sensitive, environmentally friendly, with good recovery and precision, which is suitable for detecting terbufos and its oxidative analogues(-sulfone,-sulfoxide) residues in plant origin foodstuffs.