超高效液相色谱-串联质谱法研究噻虫嗪在双孢蘑菇中的残留动态及安全性评估

Residue dynamics and safety assessment of thiamethoxam in Agaricus bisporus by ultrahigh performance liquid chromatography-tandem mass spectrometry

通过乙腈溶解和分散固相萃取净化,采用超高效液相色谱-串联质谱法研究了双孢蘑菇(Agaricus bisporus)中噻虫嗪的残留动态。结果表明:在0. 01—0. 5 mg/L范围内,目标化合物和仪器响应呈良好的线性关系:y=1E+07x-51 846,R^2=0. 9993,在0. 01 mg/kg、0. 05 mg/kg、0. 10 mg/kg 3个添加水平下,方法的回收率为89%—103%,相对标准偏差RSD小于8%,定量限为0. 01 mg/kg。通过田间试验,考察了双孢蘑菇中噻虫嗪的残留水平及其消解规律:当施药浓度为0. 075 g a. i. m^2,施药一次时,噻虫嗪在双孢蘑菇中的半衰期为6. 3 d,施药后14 d,降解水平超过80%,在双孢蘑菇中的消解基本符合一级动力学模式。针对目前双孢蘑菇上噻虫嗪限量标准的空白,推荐噻虫嗪在双孢蘑菇中的MRL值为0. 5 mg/kg,安全间隔期为7 d。根据试验中噻虫嗪的残留中值计算出普通人群噻虫嗪的每日摄入量占日允许摄入量的0. 8%左右,认为该农药残留对一般人群健康的风险是可接受的。

The residue dynamics of thiamethoxam in Agaricus bisporus were studied by ultrahigh pefformance liquid chromatography-tandem mass spectrometry （UHPLC-MS）after extraction by acetonitrile and purification by dispersive solid phase extraction. The results showed that in the range of 0. 014. 5 mg/L, the target compound showed a good linear relationship with the instrumental response ：y = 1 E ＋ 07x -51 846, R2 = 0. 9993. The recovery was 89% 103% ,RSD was less than 8% and the quantitative limit was 0.01 mg/kg at the thine levels of 0.01 mg/kg,0.05 mg/kg and 0.10 mg/kg. The residue level of thiamethoxam in A. bisporus was studied by field experiments. When the thiamethoxam concentration was 0. 075 g a. i./m2, the half-life of thiamethoxam in A. bisporus was 6.3 days,and the degradation level exceeded 80% 14 days after application. The degradation in A. bisporus basically conformed to the first-order kinetic model. Aiming at the blank of thiamethoxam in A. bisporus standard, it was recommend that the MRL value of thiamethoxam in A. bisporus was 0.5 mg/kg, and the safe interval was 7 d. According to the residual median value of thiamethoxam in the experiment, the daily intake of thiamethoxam accounted for about 0.8% of the daily allowable intake. It was considered that the risk of thiamethoxam residue to the health of the general population was acceptable.