溴虫腈在土壤的残留动态

Dynamic residue of chlorfenapyr in soil

通过超临界流体萃取技术结合气相色谱法,研究了土壤中溴虫腈的残留降解动态。正交试验L9（33）结果表明,在流量25-27 m3·h^-1,夹带剂甲醇1 mL·g^-1样品时,最佳萃取条件为压力25 MPa,温度39℃,时间30 min。超临界萃取试验结果表明,主要影响因素对溴虫腈回收率的影响高低程度依次为萃取温度,萃取时间,萃取压力。验证试验表明,在上述最佳萃取条件下,溴虫腈添加量为10μg、100μg、200μg时,回收率分别是105.00%、80.33%、102.33%,变异系数分别是7.32%、4.58%、4.95%。降解动态试验表明溴虫腈在土壤中的消解动态方程为Ct=0.097 2e-0.4501 t,R2=0.973 7,t1/2=2.4 d。溴虫腈10%悬浮剂（商品名除尽）在推荐剂量50 mL.（667 m2）^-1或100 mL.（667 m^2）^-1使用2-3次,3-7 d后在土壤中残留量为6.44-23.58μg·kg^-1,消解速度较快,属于易降解农药,可合理使用于无公害蔬菜生产。

The supercritical fluid extraction （SFE） technique was used to analyze the dynamic residue of chlorfenapyr in soil, and the carbon dioxide and methanols were used as carrier and improver in the experiment. The optimal conditions obtained by orthofonal comparison for extracting the chlorfenapyr were pressure 25 MPa, temperature 39 ℃ and extracting time 30rain, which was under 1 mL· g^-1 improver and 25-27 m^3· h^-1 flow velocity. The main influence factors were temperature, extracting time and then press in turn The results in verify test showed that the average fortified recoveries of chlorfenapyr in soil samples were 105.00%, 80.33% and 102.33%, and the CVs were 7.32%, 4.58%, and 4.95%, when the samples added with 10, 100, and 200 μg, respectively. The dynamic residue fitted to the formulation- Ct = 0.097 2e^-0.450 it, R2=0.973 7, t1/2=2.4 d, with the above the optimal extracting method. The concentration of residue taken from soil were 6.44-23.58 μg ·kg^-1 after 3-7 d application twice or thrice with chlorfenapyr 10% SC （trade name CHU JING） at 50 and 100 mL. per 667 m^2 in field trial, which indicated that chlorfenapyr is degradable and deserves to use in vegetable production.