【作者】 朱宏；

【导师】 刘贤金；

【作者基本信息】 南京农业大学 ， 农业昆虫与害虫防治， 2012， 硕士

【摘要】 丙森锌是一种广谱、速效的保护性杀菌剂。本文通过在南京市、长沙市和南宁市2010年和2011年两年的残留田间试验,研究了丙森锌及其代谢物在水稻上的残留特性,为丙森锌在水稻上的安全使用提供科学依据。1分析方法的建立本文建立了丙森锌在水稻上(植株、土壤、田水、稻米、稻壳)的两种残留分析方法(紫外分光光度法、邻丙二胺衍生化法)和丙森锌的代谢物丙撑硫脲在水稻(植株、土壤、稻米、稻壳)中的残留分析方法。丙森锌酸解后释放的二硫化碳经乙酸铜和二乙醇胺的乙醇溶液吸收,然后在435nm处用分光光度法进行测定。当添加浓度为0.02-1.0mg/kg,回收率为82.9%-94.5%,相对标准偏差RSD为2.0%-8.2%,最低检出浓度为0.02mg/kg.丙森锌的酸解产物邻丙二胺(PDA)经离子交换树脂净化后,与五氟苯甲酰氯进行衍生化,衍生物用硅胶柱净化后以配有电子捕获检测器的气相色谱仪进行测定。在添加浓度(以PDA量计)为0.02-0.50mg/kg,回收率达到85.4%-105.9%,变异系数为1.2%-6.50%,最低检测浓度为0.02mg/kg.样品中的丙撑硫脲用乙腈溶液振荡提取后通过高效液相色谱(紫外可见检测器)进行测定。在添加浓度为0.02-0.5mg/kg时,丙撑硫脲在植株、土壤、稻壳和糙米中添加回收率为81.3%-110.6%,RSD为1.5%-6.4%,最低检测浓度为0.02mg/kg。实验结果表明,以上三种方法均满足农药残留分析要求。2残留消解动态研究通过丙森锌在水稻上的残留量动态研究(分光光度法),结果表明：丙森锌在水稻植株中的半衰期为3.6-4.7d,在土壤中的半衰期为3.4-12.4d,在田水中的半衰期为1.0-3.7d。通过丙森锌在水稻上的残留量动态研究(PDA衍生化法),结果表明：丙森锌在水稻植株中的半衰期为3.2-4.4d,在土壤中的半衰期为1.4-10.7d,在田水中的半衰期为1.2-5.3d。3最终残留量研究丙森锌最终残留量：以二硫化碳量计,植株中0.203-2.725mg/kg,土壤中<0.02-0.130mg/kg,糙米中0.024-0.562mg/kg,稻壳中0.070-1.648mg/kg;以PDA量计：植株0.082-1.371mg/kg,土壤<0.02-0.058mg/kg,糙米<0.02-0.432mg/kg,稻壳0.041-0.811mg/kg.70%丙森锌可湿性粉剂按最高剂量300克／亩、施用3次、间隔期45天施药,丙森锌在糙米中的最终残留量均小于0.5mg/kg.植株、土壤、糙米和稻壳中的丙撑硫脲最终残留量均小于最低检测浓度0.02mg/kg.更多还原

【Abstract】 Propineb is a protective fungicide, which is broad-spectrum and available. In order to clarify its residual levels in rice, in this paper, two years(2010,2011) field experiment was carried out in Nanjing, Changsha and Nanning. It will provide a scientific basis on the safe use of propineb in the rice.1. Establishment of analytical methodThis paper established the residual analysis method of propineb in rice (soil, water, rice stem, rice hull, rice), and propylenethiourea(PTU) in rice (soil, rice stem, rice hull, rice). In the residue analysis of propineb, there were two ways, one was sepectrophotometry and the other was derivatization of propylenediamine(PDA).The caabon disulfide liberated during the acid hydrolysis was absorbed in an ethanolic solution of cupric(Ⅱ)acetate and diethanolamine.The absorption was measured by sepectrophotometry at435nm. The average recovery of propineb was82.9%-94.5%(RSD2.0%-6.0%)within the addition concentration of0.02-1.0mg/kg, and the minimum detectable concentration was0.02mg/kg.After acid hydrolysis of propineb, the eluate containing propylenediamine was derivatized with pentafluorobenzoylchloride, which was cleaned up by column chromatography on silica gel and then determined by gas chromatography using election-capture detector (GC-ECD). The result showed that the recovery from untreated control samples fortified with PDA at levels of0.02-0.5mg/kg were ranged from85.4%-105.9%(RSD1.2%-6.5%), and the limits of quantification were0.02mg/kg.The PTU in samples was extracted by acetonitrile and then detected by high performance liquid chromatography. The average recovery of propineb was81.3%-110.6%(RSD1.5%-6.4%)within the addition concentration of0.02-0.5mg/kg, and the minimum detectable concentration was0.02mg/kg.The experimental results show that the above three methods to meet the pesticide residue analysis requirements.2. Degradation dynamics of propinebThrough two years of detecting the residues of the propineb in rice, the results showed that:With the method of sepectrophotometry, the half-life was found to be3.6-4.7d in the stem,3.4-12.4d in the soli,and1.0-3.7d in the water; the half-life was3.2-4.4d in the stem,1.4-10.7d in the soli and1.2-5.3d in the water by the method of derivatization.3. Final residuesThe final residues of propineb,determined as CS2, was0.203-2.725mg/kg in the stem,<0.02-0.130mg/kg in the soil,0.024-0.562mg/kg in the rice,0.070-1.648mg/kg in the rice hull. The final residues of propineb determined as CS2was0.082-1.371mg/kg in the stem,0.02-0.058mg/kg in the soil,0.02-0.432mg/kg in the rice,0.041-0.811mg/kg in the rice hull.According to the highest dose of300g/acre, wettable powder of70%propineb applied three times at intervals of45days and the final residues of propineb(determined as PDA)in brown rice were less than0.5mg/kg, on the mean while, PTU were less than minimum detectable concentration.更多还原