联苯菊酯在甘蓝及土壤中的消解动态

Degradation dynamics of bifenthrin in cabbage and soil

【目的】建立残留联苯菊酯的检测方法,研究质量分数1%联苯菊酯·噻虫咹颗粒剂中联苯菊酯在甘蓝Brassica oleracea和土壤中的残留及消解动态。【方法】在广东广州市、广西南宁市和湖北潜江市进行田间试验,联苯菊酯在0.01~1.00 mg·kg^(-1)水平范围内取0.01、0.10、0.50 mg·kg^(-1)添加,样品中的联苯菊酯经乙腈超声波辅助提取,弗罗里硅土固相萃取柱净化,气相色谱(GC-ECD)检测,外标法定量,得到联苯菊酯在甘蓝和土壤中的残留及消解动态。【结果】联苯菊酯在甘蓝中的平均回收率为83.64%~96.44%,相对标准偏差为3.26%~7.24%;在土壤中平均回收率为86.76%~90.09%,相对标准偏差为2.17%~4.94%。联苯菊酯在土壤中的残留半衰期为6.77~13.51 d,在甘蓝中未检出。【结论】联苯菊酯属易降解农药;该施药方法安全,值得借鉴。

[ Objective ] To establish a detection method of bifenthrin, and to study the residue and degra- dation dynamics of bifenthrin in the form of 1% bifenthrin clothianidin granules in cabbage and soil. [ Method ] Field experiments were conducted in Guangzhou of Guangdong, Nanning of Guangxi and Qian- jiang of Hubei. Bifenthrin was added at three levels of 0.01,0. 10,0.50 mg·kg-1 in the range from 0.01 to 1.00 mg · kg-1. Bifenthrin was extracted from cabbage and soil using ultrasonic-assisted aceto- nitrile extraction, cleaned up using a florisil solid phase extraction column, then detected by GC with ECD detector, and quantified by external standard method. [ Result ] The average recovery rates of bifenthrin in cabbage were 83.64 % -96. 44% with 3.26% -7.24% RSD, and the average recovery rates in soil were 86. 76% -90. 09% with 2. 17% -4. 94% RSD. The half-life of bifenthrin in soil was 6.77 - 13.51 d. No bifenthrin residue was detected in cabbage at harvest. [ Conclusion] Bifenthrin is an easily degradable pesticide. Using 1% bifenthrin · clothianidin granules as pesticide is safe and recommended.