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[目的]建立玉米中2,4-滴异辛酯残留量气相色谱质谱检测方法,并研究了其在植株和玉米中的消解动态和最终残留。[方法]样品用丙酮提取后,三氯甲烷萃取,经弗罗里硅土和活性炭层析柱净化,用气相色谱质谱联用仪进行测定。[结果]2,4-滴异辛酯在0.1~2.0 mg/L质量浓度范围内呈线性,相关系数0.9993;添加3个不同质量分数,平均回收率为88.7%~101.7%;变异系数为7.2%~9.0%。施药剂量为推荐剂量的1.5倍(3,058.5 g a.i./hm2)时,2,4-滴异辛酯在玉米植株中的半衰期为2.4~6.7 d,68%乙草胺.2,4-滴异辛酯.莠去津悬浮剂2,038.9、3,058.5 g a.i./hm2两个剂量,施药1次,测得收获期植株、玉米中2,4-滴异辛酯的残留量均低于美国规定的MRL0.5 mg/kg。[结论]按照推荐剂量2,038.9 g a.i./hm2处理,建议我国2,4-滴异辛酯在玉米上的MRL值可暂定为0.5 mg/kg,施药次数1次。
[Objective] The research aimed to establish a method for the determination of 2,4-D isooctyl residues in corn by gas chromatography-mass spectrometry and to study its digestion dynamics and final residues in plants and maize. [Method] The samples were extracted with acetone and extracted with chloroform. The samples were purified by Florisil and activated charcoal chromatography and determined by GC / MS. [Result] 2,4-Dioctyl-octyl was linear in the concentration range of 0.1-2.0 mg / L with a correlation coefficient of 0.9993. The average recovery of three different mass fractions was 88.7% -101.7% with a coefficient of variation of 7.2 % ~ 9.0%. The half-life of 2,4-isooctyl ester in corn plants was 2.4-6.7 days with 68% acetochlor at 1.5 times the recommended dose (3,058.5 g ai / hm2) Octyl Atrazine Suspension 2.038.9,3,058.5 g ai / hm2 two doses, spraying 1, measured the harvested plants, corn 2,4-Dioctyl ester residues were lower than the US MRL0 .5 mg / kg. [Conclusion] According to the recommended dose of 2,038.9 g a.i./hm2, it was suggested that the MRL value of 2,4-D isooctyl ester on maize in China could be tentatively set at 0.5 mg / kg and the application frequency was 1 time.