【作者】 齐伟婧；

【导师】 邓秀新；

【作者基本信息】 华中农业大学 ， 果树学， 2007， 硕士

【摘要】 有机磷农药在农业生产中起到举足轻重的作用。目前，在我国的农药市场中，有机磷农药仍作为主要的杀虫剂得到广泛的应用。但由于对于农药的不合理使用，造成了农药残留对于植物、动物、大气、水源等周围一切环境的污染，我们的很多农产品和加工食品同样也受到农药残留的污染。随着人们对食品安全意识的加强，农药残留检测这门应用性学科被更加重视，农药残留检测方面的标准也逐步得到完善。农药残留分析是从复杂混合物中进行痕量组分分析，整个过程包括样品制备、纯化富集、分离检测和综合分析等步骤，它要求分析方法灵敏度高、回收率高、重现性好、操作简单易行。进行农药残留分析方法的研究主要是在样品前处理技术和检测技术方面进行优化，开展农药残留的消解动态实验，对于指导农民用药时间，生产高品质农产品，增强我国农产品的竞争力有重要意义。本实验初步建立了固相萃取-高效液相色谱(SPE-HPLC)检测柑橘中有机磷农药残留的方法，同时也对毒死蜱在柑橘中的消解动态规律进行了研究。首先是SPE-HPLC检测柑橘中有机磷农药残留的方法的初步建立。样品的前处理技术：分别用丙酮、乙酸乙酯提取柑橘果皮果肉中的3种有机磷农药残留(乐果、杀扑磷、毒死蜱)，用SPE方法净化样品萃取液，分别用丙酮、乙酸乙酯淋洗后浓缩等待进样。检测时采用HPLC，PDA检测器，乙腈与水做流动相，进行梯度洗脱(0-6.5min乙腈：水=50％：50％；6.5-25min乙腈：水=50％：50％变化到乙腈：水=70％：30％：25-30min乙腈：水=70％：30％；30-35min乙腈：水=70％：30％变化到乙腈：水=50％：50％)。最后进行回收率、精密度和灵敏度检验，3种有机磷农药的添加回收率达76.11％-101.82％，相对标准偏差为4.31％-8.49％，最低检测浓度分别为0.012mg／kg，0.015mg／kg，0.021mg／kg符合单次洗脱进行多残留分析的要求。本文还对毒死蜱在柑橘中的消解动态规律进行了研究。结果表明：果皮的农药残留量和消解速率都比果肉中的大，而且不同浓度处理对果实的不同部位农药半衰期无显著性差异。更多还原

【Abstract】 Organophosphorous pesticides are very important in agricultural production. So far, they are considered to be the mainly employed insecticides among pesticides in China. Irrational usage of pesticides pollute environment including plants, animals, atmosphere and water bodies. Farm production and processed foods are also in danger of being polluted by pesticide residues. As safe consciousness about foods strengthened by the mass, pesticide residue assay as a practical science is attached more and more attention and criterions of pesticide residuals are optimized gradually.Pesticide residue assay is a technique that determines the trace components in a complex mixture, the process of witch including sample preparation, purification, enrichment, separation, detection and analyses. The technique is required to be high sensitivity, efficient recovery rate, good recurrence and simple and workable operation. The study on pesticide residue detection methods is to optimize the pretreatment techniques and detection techniques. The study on pesticide residue degradation dynamics plays important roles in instructing properly usage of pesticides, high quality farm production and national farm production competitiveness enhancement.In the study we primarily optimized the method of Solid Phase Extraction-High Performance Liquid Chromatography (SPE-HPLC) in organophosphorous pesticides’ detection in Citrus, and revealed the degradation dynamical rhythm of chlorpyriphos in Citrus.The method in organophosphorous pesticides’ detection by using SPE-HPLC is described as follows: The optimized sample pretreatment techniques included organophosphorous pesticides extraction from Citrus’s pericarp and pulp by acetone and ethyl-acetone: optimizing SPE method to purify extractions samples, after eluted with acetone and ethyl-acetone, concentrating the elution solution before determination. Determination was carried out by using HPLC coupled with Photodiode Array Detector. Gradient elution method was employed by starting from 50% acertonitrile and 50% water to 70% acertonitrile and 30% water during 6.5-20mins and back to 50% acertonitrile and 50% waters during 30-35mins. Furthermore, the recoveries, recurrences and the lowest detection limits were determined. The recoveries was between 76.11%-101.82%, RSD 4.31%-8.49%, the lowest limit of the three organophosphorous pesticides was 0.012mg/kg, 0.015mg/kg, 0.021mg/kg respectively, witch meet with the requirements of determine many pesticide residues in a single run.The degradation dynamics rhythm of chlorpyriphos in Citrus was also studied. The results showed that more pesticide residue and faster were found in pericarp of Citrus than in the pulp, the half life of the pesticide was found no significant difference in different part of Citrus treated with by different pesticide concentrations.更多还原