多菌灵在浙麦冬及其土壤中的消解动态研究
Residue Decline Dynamics of Carbendazim in Radix Ophiopogonis and Soil
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摘要: 为评价多菌灵在浙麦冬及其土壤中的安全性,建立其在浙麦冬上的使用规范,采用高效液相色谱法研究了多菌灵50%可湿性粉剂(WP)在浙麦冬及其土壤中的残留动态。结果表明,多菌灵在添加水平0.05~2.00 mg/kg范围内的平均回收率在84.6%~98.3%之间,相对标准偏差均低于6.7%。在有效成分含量(下同)0.675和1.000 kg/hm2两个施药剂量下,多菌灵50% WP在浙麦冬土壤中的半衰期为5.74~7.07 d,在茎叶上的半衰期为3.60~5.35 d,在根中残留量先升后降,其半衰期为2.01~3.60 d。多菌灵在浙麦冬及其土壤中易降解,当施药剂量较高或原始沉积量 较高时,所对应的半衰期较短。若多菌灵在浙麦冬及其土壤中的最高残留限量推荐值为0.1 mg/kg, 每年以0.675 kg/hm2的剂量喷施2次,则建议安全间隔期为15 d。Abstract: Residue dynamics of carbendazim in Radix Ophiopogonis and cultivated soil was studied.The average recoveries of carbendazim at fortified level 0.05- 2.00 mg/kg in Radix Ophiopogonis and soil were 84.6%- 98.3%,with RSDs of less than 6.7%.The half lives of carbendazim were 5.74- 7.07 d in the cultivated soil,3.60- 5.35 d on the leaf and 2.01- 3.60 d in the roots,respectively.When 0.675 kg(ai)/hm2 carbendazim was sprayed twice a year,15 days were proposed as the minimum preharvest interval of carbendazim in the Radix Ophiopogonis if 0.1 mg/kg was considered as the MRL of carbendazim in the Radix Ophiopogonis.
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