水稻及其生长环境中吡蚜酮残留的研究

【作者】 杨辉；

【导师】 任凤莲；

【作者基本信息】 中南大学 ， 分析化学， 2011， 硕士

【摘要】 吡蚜酮(pymetrozine),化学名4,5-二氢-6-甲基-4-(3-吡啶亚甲基氨基)-1,2,4-3(2H)-酮,是瑞士诺华公司开发的一种有全新结构的吡啶类或三嗪酮类杀虫剂。吡蚜酮对害虫具有触杀作用,同时还有内吸活性,因此既可用作叶面喷雾,也可用于土壤处理。据报道,日本、欧盟等发达国家已经制定了毗蚜酮在水稻上的最高残留限量(MRL),目前中国尚未制定吡蚜酮在水稻中的最高残留限量。因此,作者于2009年8月-2011年3月拟采用室内与田间试验相结合的方法,对吡蚜酮在水稻以及环境介质中的残留行为进行系统研究,以期为该新型杀虫剂品种的环境安全性评价以及合理安全地应用于水稻田防治害虫提供科学基础。主要研究成果如下：第一,研究建立了采用内装C18键合固定相(5μm)的VP-ODS(200 mm×5.0mmi.d)不锈钢柱,以乙腈+水=15+85(V/V)为流动相体系,光电二极管阵列检测器检测,外标法定量的高效液相色谱法检测水稻中吡蚜酮残留的分析方法。分别在稻秆、谷壳、糙米样品中添加质量浓度为0.02～1.00 mg/L时5个不同质量浓度水平的吡蚜酮标准溶液,其平均回收率分别为90.47%-97.95%、93.40%100.38%和95.22%-99.44%,相对标准偏差分别为1.57%-3.49%、1.07%-2.00%和1.32%-2.40%。说明所建立方法的准确度,精密度和灵敏度均较高,符合农药残留分析的要求,具有简便,快速,成本低和可靠等优点。第二,研究了吡蚜酮对水稻生长环境介质的影响,建立了采用反相高效液相色谱法检测田土和田水中的吡蚜酮残留的分析方法。添加浓度在0.02 mg/kg-2 mg/kg范围内,土壤中的平均添加回收率在85.35%-90.84%之间,相对标准偏差在4.35%-9.28%之间；在田水中的平均添加回收率在94.30%-96.92%之间,相对标准偏差在2.57%-5.61%之间。说明方法满足本残留试验和农药残留分析的要求。第三,对50%吡蚜酮水分散粒剂在水稻、田水和土壤中的消解动态和最终残留实验进行了研究。结果表明：吡蚜酮在水稻和环境中的消解动态均符合一级反应动力学模式。在水稻植株和田水中的降解速度较快,在田土中降解相对较慢,属于易降解农药。更多还原

【Abstract】 Pymetrozine,4,5-dihydro-6-methyl-4-(3-methyl-amino pyridine)-1,2,4-3 (2H)-ketone, was a novel selective insecticide whose basic structure is a pyridine. It was discoveried and developed by Novartis in Swiss. Pymetrozine kill pests very quickly because of contact action and the absorption activity, so can be used for foliar spray and soil treatment. According to reports, Japan, EU and other developed countries has been developed maximum residue limits (MRL) of pymetrozine in rice, but China has not yet developed. Therefore, in August 2009～March 2011, the authors develop a systematic study about pymetrozine residues in rice and environmental media, by the method of combining laboratory and field trial, in order to assess the NMRs and work out the reasonable application guidelines and the proper used in rice fields. The main results are as follows:First of all, a quantitative high performance liquid chromatography method has been developed for the determination of Pymetrozine residues in rice using photodiode array detector. The analysis was performed on a C18 stainless steel column (200mm×5.0 mm i.d.) with mixture of methanol-water (15:85, V/V) as the mobile phase. The limit of detection was 0.02 mg/kg for Pymetrozine (S/N=3). The average recovery of five spiked concentration levels for Pymetrozine in Rice plant, rice chaff, brown ricewere 90.47%～97.95%,93.40%～100.38% and 95.22%～99.44%, respectively. The relative standard deviation (RSD) was 1.57%～3.49%,1.07%～2.00% and 1.32%～2.40% respectively. The results indicated that the method was fast, sensitive, simple, reproducible and practical for the residue detection and analysis of Pymetrozine in aquatic systems.Secondly, a quantitative high performance liquid chromatography method was established for the determination of Pymetrozine in rice growing environments.At the concentration range from 0.02 mg/kg to 2.00 mg/kg, the average recoveries of Pymetrozine in soil and water were 85.35%～90.84%,94.30%～96.92%, respectively. The corresponding relative standard deviation (RSD) was 4.35%～9.28%, 2.57%～5.61%, respectively. The results indicated that the method accords with demands of residue analysis of pesticide.Finally,with the mentioned method, dissipation dynamics and the terminal residues of Pymetrozine in rice, water and soil had been studied in Hunan and Henan. The results indicate that the degradation of rice, water and soil was in accordance with the regression equation. The results showed that:The degradation of Pymetrozine in rice, water and soil were followed first-order kinetic equation, its degradation was rapid and it belongs to the easy degradation pesticides.更多还原