超高效液相色谱-飞行时间质谱法测定蔬菜中辛硫磷残留量

Determination of phoxim residue in vegetables by ultra performance liquid chromatography-quadrupole time of flight mass spectrometry

目的建立超高效液相色谱-飞行时间质谱法测定蔬菜中辛硫磷农药残留的分析方法。方法蔬菜样品经乙腈提取,45℃水浴氮吹至近干,丙酮定容,经超高效液相色谱-飞行时间质谱(ultra performance liquid chromatography/time of flight mass spectrometry(UPLC-TOF MS)检测。结果辛硫磷的保留时间为13.34 min,在1~400μg/L范围内线性良好,相关系数r大于0.999,方法检出限为1μg/L。将该方法用于西葫芦、白萝卜、小白菜、西红柿、葱等常见蔬菜的辛硫磷残留检测,结果表明辛硫磷的添加回收率在87.0%~99.9%之间,相对标准偏差为5.14%~8.30%。结论该方法操作简单、准确高效,可以用于蔬菜中辛硫磷残留的日常检测。

Objective To establish a method for determination of phoxim residue in vegetables by ultra performance liquid chromatography-quadrupole time of flight mass spectrometry （UPLC-Q-TOF-MS）. Methods The sample was extracted by acetonitrile, and dried by nitrogen at 45 ℃. The solution was redissolved with acetone and determined by UPLC-Q-TOF-MS. Results The retention time of phoxim was 13.34 min. Phoxim had good linear relationships in the range of 1-400 μg/L and correlation coefficients was above 0.999. The limit of detection was 1 μg/L. The established method was used for the determination of phoxim residue in other vegetables such as squash, turnip, Chinese cabbage, tomatoes, scallion, the content of phoxim in the different samples were determined with high recoveries of 87.0%-99.9% through the addition of standard substance and the relative standard deviation were between 5.14%-8.30%. Conclusion This method is simple, accurate and efficient, which can be used for routine detection of phoxim residue in vegetables.