苯醚甲环唑在黄瓜及土壤中的残留消解行为研究

为了研究苯醚甲环唑在黄瓜地使用后的生态环境安全性,指导苯醚甲环唑及其制剂的科学合理使用,通过添加回收率实验,借助GC检测技术,研究并建立了黄瓜和土壤中苯醚甲环唑残留量的分析与检测方法,并应用该方法研究了10％苯醚甲环唑水分散粒剂在黄瓜地使用后,苯醚甲环唑在黄瓜及土壤中的残留消解动态.结果表明：①黄瓜和黄瓜地土壤样品中残留的苯醚甲环唑可用丙酮提取,二氯甲烷萃取,再经弗罗里硅土（Florisil）层析柱净化,最后用GC-ECD（Ni63）检测,方法的最小检出量为1.0 ×10-11 g,其在黄瓜和黄瓜地土壤样品中的最小检出浓度均为0.05 mg/kg；②当添加浓度为0.05～1.00 mg/kg时,苯醚甲环唑在黄瓜和黄瓜地土壤中的添加回收率在89.22％～99.80％之间,相对标准偏差在1.04％ ～5.41％之间,符合农药残留量分析与检测的技术要求；③10％苯醚甲环唑水分散粒剂在黄瓜地使用后,苯醚甲环唑在黄瓜和黄瓜地土壤中的消解半衰期在6.46～9.94 d之间,表明苯醚甲环唑在黄瓜地中属于较易降解农药.

Residue and Degradation Behavior of Difenoconazole in Cucumber and Its Soil

In order to research the ecological environment safety of difenoconazole after using in cucumber field, and guide the scientific and rational use of difenoconazole and its preparations, the remnant allowance examination method of the difenoconazole in cucumber and soil was studied and established by adding recovery experiment with GC technique, and the residue and degradation dynamics of difenoconazole in cucumber and soil was studied after 10% difenoconazole WG was used in cucumber field by this method. The results showed that ： （1）The residue of difenoeonazole in cucumber and soil could be extracted by acetone, extracted with diehloromethane, and then purified by a florisil column, finally detected with GC - ECD. And the limit of detection with this method was 1.0 x 10 -H g- The lowest detectable concentrations in cucum- ber and soil were 0. 05 mg/kg. （2）When the added concentration ranged from 0. 05 to 1.00 mg/kg, the recoveries changed from 89. 22% to 99.80% , with the variation coefficients between 1.04% and 5.41%. The result suggested that the resi- due determination method of difenoconazole could meet the requirement of pesticide residues technical specifications. （3） After use of 10% difenoconazole WG in cucumber field, the degradation half life of difenoconazole in cucumber and soil was 6.46 - 9. 94 d. It showed that difenoconazole degraded easily in cucumber field.