摘要
为制定吡蚜酮在水稻上的安全使用标准,采用田间试验的方法研究吡蚜酮在水稻、土壤、水中的残留与降解动态,应用高效液相色谱法进行定性和定量分析。结果表明,吡蚜酮在水稻茎秆、土壤、水中的消解较快,其半衰期分别为1.2～1.9 d、10.1～10.6 d、6.2～7.0 d。施药量为135.0 g(ai)/hm^2,使用2～3次,末次施药距采收期间隔14 d时,吡蚜酮在水稻糙米及土壤中的最高残留量分别为0.064 mg/kg和0.083 mg/kg,低于日本制定的大米中吡蚜酮最大残留限量值(0.1mg/kg),说明吡蚜酮属于低残留、易降解农药。
The present paper intends to introduce a series of field ex- perimental research results to disclose the dissipation rate and the ter- minal residue in the rice stalks, soil, and farming sewage, in order to make up a standard procedure for safe use of pymetrozine in rice and soil. All the samples collected were adopted to determine the residue dynamic in-situ by using the HPLC - UV method. For our research purpose, we have arranged all our field experiments to be done in the following procedure： First of all, all the rice stalk samples were put to be homogenized with the methanol by using a homogenizer. When the samples were put filtrated in a vacuum container, the methanol would be let to evaporate at the temperature of 45℃. After the water phase was extracted by the crude oil ether with the supernatant dis- carded, it would be let extracted four times by the diehloromethane. Then the substrate organic phase dichloromethane were let to dry up by anhydrous sodium sulfate and evaporated under vacuum eonditian. The dried extracted samples should be made to reconstitute in 5 mL aqueous ammonia. Cleaned by SPE column, the samples should be let detected by HPLC - UV. For soil, samples were extracted by methanol in a rotary shaker for about 12 hours. After filtrated under vacuum, the soil was extracted once again by ultrasonic. Next opera- tion should be done in the same way as to the stalk samples. Two years results of our experiments show that the residue of pymetrozine would disappear quickly in both rice stalk in the soil and the water. The half-life periods for the rice stalk, soil and water were 1.2 - L9 d, 10.0 - 10.6 d and 6.2 -7.0 d, respectively. When the rice was treated by 50% of pymetrozine WDG in recommended doses of 1.5 times, and twice and thrice, respectively, the maximal final residue of pymetrozine in the rice and soil samples would be 0.064 mg/kg and 0.083 mg/kg, respectively, 14 days later after the last applica- tion. The results thus suggest that pymetrozine proves to be a kind of insecticide with low residue, which is also easy to get dissipated.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2011年第5期15-18,共4页
Journal of Safety and Environment
基金
中央公益性科研院所基本业务费(农业部环境保护科研监测所)项目(2009-tyj-02)
