己唑醇在苹果和土壤中的残留及安全使用评价

Residue and Application Safety Assessment of Hexaconazole in Apple and Soil

[方法]采用田间试验的方法，对己唑醇在苹果及土壤中的残留消解动态及最终残留量进行了研究。气相色谱电子捕获检测器进行定量分析。【结果】消解动态试验结果表明：己唑醇在土壤中的半衰期为7．1-14．4d，在苹果中的半衰期为7．1-8．8d；最终残留量试验结果表明：5％己唑醇悬浮剂按施药剂量为50、75mga．i．／kg，连续喷药3—4次，施药间隔期7d，喷药后21d土壤中己唑醇残留量〈0．01-0．215mg／kg，苹果中己唑醇残留量为0．011-0．055mg／kg，均低于0．1mg／kg（MRL）。【结论】推荐5％己唑醇悬浮剂在苹果上使用安全间隔期为21d。

[Methods] A field experiment was conducted to reveal residual degradation dynamics and the final residues of hexaconazole in apple and soil, the residues of hexaconazole in apple and soil were determined by GC with ECD. [Results] The degradation dynamic test results showed that the half-life of hexaconazole in soil was 7.1- 14.4 d, and the half-life of hexaconazole in apple was 7.1-8.8 d. The final residue tests showed that hexaconazole 5% SC was sprayed for 3 to 4 times continuously at application dose 50, 75 mg a.i./kg with 7 d spraying interval, 21 d after spraying, the final residues of hexaconazole in soil were less than 0.01-0.215 mg/kg and apple were 0.011-0.055 mg/kg, which were lower than 0.1 mg/kg（MRL）. [Conclusions] Therefore, preharvest interval was suggested to be 21 d when hexaconazole was applied at recommended dosage 5% SC for apple.