韭菜中农药多残留检测及吡虫啉残留行为研究

发布时间：2018-03-05 18:16

本文选题：韭菜　切入点：有机磷　出处：《湖南农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：为控制韭菜中农药残留,本文建立了韭菜中6种有机磷和6种烟碱类两类农药的超高效液相色谱-串联质谱(UPLC-MS/MS)方法,通过残留消解动态和最终残留试验研究吡虫啉在韭菜上的残留行为。主要研究结果如下：建立了韭菜中6种有机磷农药的UPLC-MS/MS的检测分析方法。样品经乙腈提取,石墨化炭黑固相萃取柱净化,UPLC-MS/MS在多反应离子监测模式(MRM)下进行检测,基质匹配标准曲线定量。结果表明：6种农药均表现为基质增强效应,在0.005、0.01 、0.05 mg/kg三个添加水平下,韭菜中6种农药的平均回收率为69.1%～110.4%；相对标准偏差(RSD,n=5)为2.2%～19.1%;在韭菜基质中检出限LOD为0.003 ng,最低检出浓度(LOQ)为0.005 mg/kg,试验结果均符合农药残留分析方法要求,该方法简单、快速、高效,适用于韭菜中农药残留检测。利用建立方法对市场韭菜进行检测,甲胺磷、对硫磷、甲基对硫磷、辛硫磷均未检出；甲拌磷的残留量为0.005～0.087 mg/kg;毒死蜱的残留量为0.005～0.171 mg/kg。建立了韭菜中6种烟碱类农药UPLC-MS/MS的检测分析方法。样品经乙腈提取,分散固相萃取净化(GCB 10 mg, PSA 50 mg, C18 50 mg, MgSO4 50 mg),利用UPLC-MS/MS在多反应离子监测模式(MRM)下进行检测,基质匹配标准曲线定量。结果表明：6种农药均表现为基质增强效应；在0.005、0.01、0.05 mg/kg三个添加水平下,6种新烟碱类农药的平均回收率为73.5%～101.3%,相对标准偏差(RSD,n=5)为1.1%-8.6%,在韭菜基质中检出限LOD为0.003 ng,最低检出浓度(LOQ)为0.005 mg/kg,试验结果均符合农药残留分析要求,该方法简单、快速、高效,适用于韭菜中农药残留检测。建立土壤中吡虫啉的UPLC-MS/MS检测分析方法。样品经乙腈提取,分散固相萃取净化(PSA 50 mg, C18 50 mg, MgSO4 100 mg),利用UPLC-MS/MS在多反应离子监测模式(MRM)下进行检测,基质匹配标准曲线定量。结果表明：在0.005、0.01、0.05 mg/kg三个添加水平下,吡虫啉在土壤中的平均回收率为86.2%-93.9%,相对标准偏差(RSD,n=5) 2.5%～7.9%;吡虫啉在土壤中检出限LOD为0.003 ng;吡虫啉在土壤中定量限LOQ为0.005 mg/kg,准确度、精密度符合农药残留分析方法的要求,该方法适用于土壤样品中吡虫啉残留检测。于2014年在山东进行了吡虫啉在韭菜上的消解动态和最终残留试验。消解动态试验结果表明：吡虫啉在韭菜和土壤中的消解符合一级动力学方程,分别为Ct=0.434e-0-362t和Ct=1.6234e-0.183t,相关系数(r)为0.978和0.906,在韭菜和土壤中的残留消解半衰期分别为1.9 d和3.8 d。吡虫啉10%颗粒剂按有效浓度225 g a.i/hm2和337.5 g a.i/hm2灌根1-2次(施药间隔期为7 d)进行最终残留试验。最终残留试验结果表明：距最后一次施药后的14d时,吡虫啉在韭菜中最终残留量低于0.017 mg/kg,在土壤中的最终残留范围0.054～0.157 mg/kg。故提出吡虫啉在韭菜中安全合理使用建议：按最高制剂用药量337.5 g a.i/hm2,最多施药2次,施药间隔期为7 d,安全间隔期为14 d。
[Abstract]:In order to control pesticide residues in Chinese chives, a high performance liquid chromatography-tandem mass spectrometry (UPLC-MS / MS) method was developed for the control of six organophosphorus and six nicotine pesticides in Chinese chives. The residual behavior of imidacloprid on leek was studied by residue digestion dynamics and final residue test. The main results were as follows: a method for the determination and analysis of six organophosphorus pesticides in leek was established. The samples were extracted by acetonitrile. UPLC-MS / MS was detected on a graphitized carbon black solid phase extraction column under a multi-reaction ion monitoring model. The matrix matching standard curve was quantified. The results showed that all of the 6 pesticides showed matrix enhancement effect, and at the three additive levels of 0.005 ~ 0.01 ~ 0.05-0. 05 mg/kg, The average recovery of 6 pesticides in leek was 69.1 mg / kg; the relative standard deviation (RSD) was 2.2 / 19.1.The detection limit was 0.003 ng / kg and the lowest detectable concentration (LOQ) was 0.005 mg / kg in leek matrix. The results of the test were all in accordance with the requirements of pesticide residue analysis method. The method was simple, rapid and efficient, and the detection limit was 0.003 ng / kg, and the lowest detectable concentration was 0.005 mg / kg. It is suitable for the determination of pesticide residues in leek. Methamidophos, parathion, methyl parathion and phoxim were not detected by the established method. The residues of phorate and chlorpyrifos were 0.005N 0.087 mg / kg and 0.005N 0.171 mg / kg respectively. A method for the determination and analysis of six niacin pesticides UPLC-MS/MS in leek was established. The samples were extracted by acetonitrile. GCB10 mg, PSA 50 mg, C18 50 mg, MgSO4 50 mg were purified by dispersive solid phase extraction (SPE). The results showed that the matrix matching standard curve was quantitative by using UPLC-MS/MS in multi-reaction ion monitoring mode. The results showed that all of the 6 pesticides showed matrix enhancement effect. The average recoveries of six new nicotine pesticides were 73.5 mg / kg, RSD = 1.1-8.6mg / kg, LOD = 0.003 ng / kg and LOQ = 0.005 mg / kg in Chinese chive matrix, respectively. The average recovery rate of six new nicotine pesticides was 73.5 mg / kg. The results met the requirements of pesticide residue analysis, and the relative standard deviation (RSD) was 1.1- 8.6mg / kg, and the detection limit was 0.003 ng / kg and the lowest detectable concentration was 0.005 mg / kg in leek matrix, and the average recovery rate of six new nicotine pesticides was 73.5 mg / kg, and the relative standard deviation (RSD) was 1.1-8.6%. The method is simple, rapid, efficient and suitable for the determination of pesticide residues in leek. A UPLC-MS/MS method for determination of imidacloprid in soil was established. The sample was extracted by acetonitrile. PSA50 mg, C18 50 mg, MgSO4 100 mg / L were purified by dispersive solid phase extraction (SPE). The results showed that the matrix matching standard curve was determined by using UPLC-MS/MS under the multi-reaction ion monitoring mode. The results showed that the results showed that at the three addition levels of 0.005mg, C1850mgand MgSO4 100mgg, the results showed that, The average recovery of imidacloprid in soil was 86.2% -93.9 with relative standard deviation (RSD) 2.5% and 7.9%; the detection limit of imidacloprid in soil was 0.003 ng / kg; the quantitative limit of imidacloprid in soil was 0.005 mg / kg / kg; the accuracy and precision of imidacloprid was 0.005 mg / kg / kg, and the accuracy and precision of imidacloprid met the requirements of pesticide residue analysis. This method is suitable for the determination of imidacloprid residues in soil samples. In 2014, the degradation dynamics and final residues of imidacloprid on leek were carried out in Shandong Province. The results showed that imidacloprid in leek and soil. The solution accords with the first-order kinetic equation, The correlation coefficient (r) was 0.978 and 0.906, respectively. The half-life of residual digestion in leek and soil was 1.9 d and 3.8 days, respectively. Imidacloprid 10% granules were irrigated with 225g a.i / ha and 337.5 g a.i / hm ~ 2 at effective concentration for 1-2 times (the interval period was 7 days). The final residue test was carried out. The results of the final residue test showed that: 14 days after the last application, The final residue of imidacloprid in leek was less than 0.017 mg / kg, and the final residue range in soil was 0.054 ~ 0.157 mg / kg. Therefore, the safe and reasonable use of imidacloprid in leek was suggested: the maximum dosage of imidacloprid in leek was 337.5 g. The application interval was 7 days and the safe interval was 14 days.
【学位授予单位】：湖南农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X592

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