联苯菊酯在甘蓝及土壤中的消解动态

【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。

Degradation dynamics of bifenthrin in cabbage and soil

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 .