【作者】 Husham NasrEldin Mustafa Hussan；

【导师】 郑永权；

【作者基本信息】 中国农业科学院 ， 农药学， 2014， 博士

【摘要】 本文采用快速、简单、廉价、有效、可靠、安全的分散固相萃取(QuEChERS)为样品前处理方法,建立了四种杀菌剂(fluopyram, tebuconazole, trifloxystrobin and trifloxystrobin acid)在蔬菜(西红柿、豇豆),水果(梨、葡萄、苹果、西瓜)和土壤中超高效液相色谱-串联质谱联用分析方法。样品采用乙腈提取,C18作为吸附剂净化,超高效液相色谱-串联质谱联用测定。多反应监测模式下,3分钟内完成了四种目标物的分离。该方法在各个基质中的检出限(LOD)为0.2～2μg kg-1,定量限(LOQs)为0.5～7μg kg-1。在0.01mg、0.1mg和1mg三个添加水平,四种杀菌剂在不同基质中的平均回收率分别为71.7%-116.4%,相对标准偏差为1.3%-20%。氟吡菌酰胺和戊唑醇在番茄和土壤中的残留动态表明：氟毗菌酰胺和戊唑醇的残留消解动态符合一级动力学方程C=Coek,且相关系数(R2)在0.9761～0.9999之间。2012-2013年,在山东、河南、北京试验点,氟毗菌酰胺番茄和土壤中的降解半衰期分别为7.0～24.5天,2.8～13.8天和8.9～21.9天。最终残留浓度分别为0.12-1.35mg,1.13-1.53mg以及<0.06-1.221mg。2011-2012年,在安徽和北京验点,氟毗菌酰胺和肟菌酯在西瓜和土壤中的降解半衰期分别为3.1～14.1天和1.9～8.1天。最终残留浓度分别为0.01-0.132mg0.01-0.083mg。同时,我们也建立了六种杀虫剂(Imidacloprid、acetamiprid、Thiacloprid、 Thiamethoxam、clothianidin and floncamid)在黄秋葵和洛神葵的残留分析方法。多反应监测模式下,3分钟内完成了目标化合物的分离。该方法在各个基质中的检出限(LODs)为0.11～5.9μg kg-1,定量限(LOQs)为0.09～17.5μg kg-1。在0.01mg、0.1mg和1mg三个添加水平,六种化合物在不同基质中的平均回收率分别为72.4%-105.1%,相对标准偏差为2.2%-20%。方法的灵敏度、准确度、精密度等均符合农药残留检测的要求,且为制定和建立这六种杀虫剂在黄秋葵和洛神葵的最大残留限量和分析方法提供了理论依据。更多还原

【Abstract】 In the present study, a quick, easy, cheap, effective, rugged and safe (QuEChERS) method based on liquid chromatography tandem mass spectrometry (LC-MS-MS) for simultaneous determination of four fungicides (fluopyram, tebuconazole, trifloxystrobin and trifloxystrobin acid) in vegetables (tomato, and cowpea), fruits (pear, grape, apple, and watermelon), and soil was developed. The fungicides were extracted from six fruits and vegetables matrices using acetonitrile and subsequently cleaned up only using octadecylsilance (C18) as sorbent prior to UPLC-MS/MS analysis. The target compounds were separated achieved in less than3.0min and detected with an electrospray ionization source in positive mode (ESI+). The limits of detection (LOD) and limits of quantification (LOQ) were obtained using the peak areas of the product ion obtained through MS/MS mode. The limits of detection (LOD) ranged between0.2to2μg kg-1, while the limits of quantification (LOQs) ranged between the0.5to7μg kg-1in different matrices. The recoveries and relative standard deviations (RSDs) were satisfying in different matrices at three spiked levels (0.01,0.1and1mg kg-1) by matrix-matched standards. The recovery results were from71.7%to116.4%with RSD in the range of1.3%to20%.The degradation of fluopyram and tebuconazole in tomato and soil also were investigated, with correlation Coefficients (R2) between0.9761to0.9999for fluopyram and tebuconazole in tomato and soil matrix. The dissipation half-lives of fluopyram in tomato and soil were7.0-24.5days,2.8-13.8days and8.9-21.9days for Shandong, Henan and Beijing respectively in two years2012and2013. The final residues of floupyram and tebuconazole ranged from0.12to1.35mg/kg in Shandong,1.13to1.53mg/kg in Henan and<0.06to1.221mg/kg in Beijing samples respectively.The degradation results of fluopyram and trifloxystrobin in watermelon and soil, the dissipation half-lives of fluopyram and trifloxystrobin in watermelon and soil were ranged between3.1and14.1days for Anhui and1.9to8.1days to Beijing for two years2011and2012. The final residues of floupyram and trifloxystrobin ranged from0.01to0.132mg/kg for Anhui and0.01to0.083mg/kg for Beijing samples respectively.For the second part of this thesis, the simultaneous residue analysis of six insecticides (imidacloprid, acetamiprid, thiacloprid, thiamethoxam, clothianidin and flonicamid) in Okra and Roselle was developed. The determination of the target compounds was achieved in less than2.0min using an electrospray ionization source in positive mode (ESI+) for imidacloprid, acetamiprid, thiacloprid, thiamethoxam, clothianidin but negative mode (ESI-) for flonicamid. The limits of quantification (LOQ) for the six insecticides ranged between the0.11to5.9kg-1, while the limits of detection (LOD) were ranged between0.09to17.5μg/kg-1in all matrices. The overall average recoveries in Roselle and Okra at three spiked levels (0.1,0.5and1mg L-1) and (0.01,0.1, and1mg L-1) ranged from72.4%to105.1%with RSD in the range of2.2-20%for all analytes. This study provides a theoretical basis to recommend MRLs and analytical method for these insecticides in Okra and Roselle.更多还原