设施环境下百菌清、毒死蜱在黄瓜中的分布特征

The distribution of chlorothalonil and chlorpyrifos in greenhouse cucumber

采用GC-MS研究大棚和露天条件下百菌清和毒死蜱在黄瓜植株中分布特征和残留量变化.结果表明:施用推荐剂量的两种农药在黄瓜各部位的残留量表现为叶片果实>茎>根,其中大棚黄瓜叶中的百菌清、毒死蜱的平均残留量是568和183mg/kg,露天黄瓜叶中百菌清、毒死蜱的平均残留量分别是176和15.9mg/kg,叶中百菌清、毒死蜱残留量远远高于其他部位.在两种种植条件下黄瓜各部分中的农药在试验时间内残留量总体都呈下降趋势,但大棚黄瓜果实上的农药的残留消解速度要比露天慢.施药14d后大棚黄瓜果实中的相应值分别为7.86和1.01mg/kg,未达到国家标准.而施药7d后,露天条件下黄瓜中的农药残留量已达到国家标准.

The distribution and degradation of chlorothalonil （CHT） and chlorpyrifos （CHP） were investigated by GC-MS after sprayed with recommended dosages on cucumber plants, which grew in both greenhouse and open field. The results showed that the level of both pesticides in greenhouse cucumber decreased in the order of leave〉〉fruit〉stem〉root. The average residual of CHT and CHP in greenhouse cucumber leaves was 568 and 183 mg/kg, while the average residual of CHT and CHP in open field cucumber leaves were 176 and 15.9 mg/kg, the residues in leaves is much higher than other parts. The residuals of CHT and CHP in cucumber were decline during test time, but the degradation in greenhouse was much slower than in open field. After 14 days application, the residuals of CHT and CHP in cucumber fruit were still above the national standards, while the residuals in the open field had met the national standards in 7th day.