72%霜脲·锰锌可湿性粉剂中霜脲氰在人参上的残留动态及最终残留

The Residual Dynamics and Final Residue of Cymoxanil in Ginseng with the Application of Cymoxanil·Mancozeb 72% WP

[目的]通过田间试验及室内残留检测,明确72%霜脲·锰锌可湿性粉剂中霜脲氰在人参、茎叶和土壤中的残留动态及最终残留量。[方法]采用高效液相色谱-串联质谱法对72%霜脲·锰锌可湿性粉剂中霜脲氰进行检测,外标法定量。[结果]添加不同质量分数的霜脲氰的平均回收率为81.37%～114.04%,相对标准偏差为1.52%～8.84%,相关系数0.9999符合残留检测要求。施药有效剂量为2754 g a.i./hm2时,霜脲氰在人参茎叶和土壤中的半衰期为6.3～11.0 d,72%霜脲·锰锌可湿性粉剂用药量为1836、2754 g a.i./hm2,分别施药1、2次,施药间隔7 d时,采收间隔期为14、45、75 d,收获期霜脲氰在茎叶中的残留量均低于0.854 mg/kg,在土壤中的残留量均低于0.027 mg/kg,在鲜人参及干人参中的残留量均低于0.01 mg/kg。[结论]建议我国霜脲氰在人参上的的最大残留限量（MRL）可暂定为0.1 mg/kg,每季最多使用次数1次,安全间隔期14 d。

[Aims] The residual dynamics and final residues of cymoxanil in ginseng root, stem, leaf and soil with the application of cymoxanil .mancozeb 72% WP were deterrninated through field experiment and indoor residual detection. [Methods] Based on the external standard method, the quantitative detections were conducted by high performance liquid chromatography tandem mass spectrometry （HPLC-MS/MS）. [Results] The results showed that the recoveries of cymoxanil were 81.37-I 14.04%, the relative standard deviations were 1.52-8.84% in ginseng root, stem, leaf and soil, and the correlation coefficient was 0.9999, which is suitable for the residue quantitative analysis of cymoxanil. The half-lives of cymoxanil were 6.3-11.0 days when spraying dosage of cymoxanil ·mancozeb 72% WP was 2754 g a.i./ha. With the dosages were 1836 and 2754 g a.i./ha in a growing season, for 1 and 2 times, the applying pesticide interval was 7 d, and the interval to harvest were 14, 45 and 75 d, the final residues of cymoxanil were below 0.854 mg/kg in stem and leaf, below 0.027 mg/kg in soil, below 0.01 mg/kg in root. [Conclusions] The MRL of cymoxanil in ginseng is temporarily suggested to be 0.1 mg/kg, and application for 1 times in a growing season, preharvest interval is 14 days.