【作者】 崔春艳；

【导师】 张红医；

【作者基本信息】 河北大学 ， 分析化学， 2017， 硕士

【摘要】 农药在提高作物产量方面发挥着巨大作用,但过度过量使用农药,会造成农产品农药残留超标,对食品安全和人类健康产生危害。因此,农残的检测是近年来的一个研究热点。甲氧基丙烯酸酯类和琥珀酸脱氢酶抑制剂类杀菌剂是目前最新的两类杀菌剂,它们具有低毒、高效、广谱等特点。为了提高杀菌剂的药效,解决农作物在生长过程中对单一杀菌剂农药产生的抗性问题,通常将不同的杀菌剂依据不同的比例进行混配,对农作物进行喷洒。目前,对于谷物、蔬菜和水果中新型杀菌剂的检测大多局限在单一种类的检测,缺少对复配杀菌剂的检测能力,且同时检测同种杀菌剂的数目少,不能有效区分同分异构体的杀菌剂。因此建立谷物、蔬菜以及水果中新型杀菌剂的农残检测、筛查和确证方法是十分有意义的。本文建立了同时测定谷物、蔬菜、水果中27种新型杀菌剂残留的分析方法。主要研究内容如下:1.对现有的农药残留样品前处理技术以及检测手段进行了综述。主要介绍了固相萃取、固相微萃取、分散固相萃取、超临界流体提取、分散液液微萃取、加速溶剂提取技术、微波辅助萃取技术、凝胶渗透色谱技术、搅拌棒吸附萃取及QuEChERS技术等方法的原理及应用;其次介绍了色谱法及色质联用技术等检测手段在谷物、蔬菜和水果中的应用;同时阐述了本文的选题背景及研究目的。2.建立了同时检测谷物、蔬菜和水果中27种新型杀菌剂的分散固相萃取-液相色谱-串联质谱(DSPE-LC-MS/MS)分析方法。样品经1%(v/v)乙酸丙酮溶液提取,以无水硫酸镁(MgSO4)作为脱水剂,经N-丙基乙二胺(PSA)、C18、无水硫酸镁(MgSO4)、多壁碳纳米管(MWCNT)混合净化剂净化,C18色谱柱分离,乙腈和0.1%甲酸水溶液(含5 mmol/L乙酸铵)梯度洗脱,多反应监测(MRM)正离子模式扫描,采用外标法定量。27种杀菌剂在0.02~200μg/kg范围内线性良好,相关系数R2≥0.9950,加标回收率在70.02%~117.6%之间,相对标准偏差(RSD)为0.01%~19.62%。27种杀菌剂检出限为0.006~16.67μg/kg,定量限为0.02~55.5μg/kg。该方法简便、快速、可靠,可用于谷物、蔬菜、水果中27种新型杀菌剂的快速测定。3.利用固相萃取-液相色谱-飞行时间质谱(SPE-LC-Q-TOF/MS)技术建立了谷物、蔬菜和水果中27种新型杀菌剂农药残留的快速筛查与确证检测方法。样品经1%(v/v)乙酸乙腈溶液提取,经Crabon/NH2柱净化,乙腈-甲苯(3:1,v/v)洗脱,C18色谱柱分离,乙腈和0.1%甲酸水溶液(含5 mmol/L乙酸铵)梯度洗脱,采用LC-Q-TOF/MS检测,外标法定量。建立了27种杀菌剂的一级精确质量数据库和二级谱图库,通过化合物的精确质量数、保留时间、同位素峰分布、同位素比例等信息对检测结果进行自动检索,从而在无对照标准品的情况下完成了27种农药的定性鉴定。结果表明,27种新型杀菌剂在0.02~300μg/L范围内线性良好,相关系数R2≥0.9950,加标回收率在71.8%~114%之间,相对标准偏差(RSD)为0.1%~21.3%(n=3)。27种杀菌剂检出限为0.01~20μg/kg,定量限为0.02~100μg/kg。该方法简便、快速、可靠,可用于谷物、蔬菜、水果中27种新型杀菌剂的快速筛查。更多还原

【Abstract】 Pesticides play a significant role in improving crop yields,but excessive use of pesticides can lead to pesticide residues in agricultural products that are harmful to food safety and human health.Therefore,the detection of pesticide residues is a hot topic in recent years.Strobilurin and succinate dehydrogenase inhibitors fungicides are the latest two kinds of fungicides.They have the characteristics of low toxicity,high efficiency and broad spectrum.In order to improve the efficacy of fungicide,solve the resistance problem of a single fungicide in the process of the growth of crops,we usually sprayed crops with different kinds of fungicides,which are mixed at various ratios.At present,the detection of new fungicides in cereals,vegetables and fruits is mostly limited to the detection of a single species,the lack of detection of complex fungicides,and the simultaneous detection of the same kind of fungicides,which can not effectively distinguish between the same body of the fungicide.Therefore,it is very meaningful to establish pesticide detection,screening and confirmation methods for new fungicides in cereals,vegetables and fruits.In this paper,an analytical method for simultaneous determination of 27 new fungicides in cereals,vegetables and fruits was established for the first time.The thesis is divided into three chapters,the main contents are as follows:1.The existing sample preparation technology and detection methods of pesticide residues are reviewed.In this paper,the principle and application of solid phase extraction,solid phase microextraction,dispersed solid phase extraction,supercritical fluid extraction,dispersion liquid microextraction,accelerated solvent extraction,microwave assisted extraction,gel permeation chromatography,stirring adsorption and QuEChERS technology are introduced.Secondly,it introduces the application of chromatography and mass spectrometry detection means in cereals,vegetables and fruits.At the same time,the background and purpose of this parper are expounded.2.A method for simultaneous determination of 27 new fungicides in cereals,vegetables and fruits using DSPE-LC-MS/MS technique was developed.Samples were extracted with acetone containing 1%(v/v)acetic acid,purified by a mixed sorbent of ethylenediamine-N-propylsilane(PSA),C18,anhydrous magnesium sulfate(MgSO4),and Multi-walled carbon nanotubes(MWCNT),separated by a reversed phase C18 column,gradiently eluted with acetonitrile and 0.1% formic acid solution(Containing 5 mmol/L ammonium acetate).Anhydrous magnesium sulfate was used as a dewatering agent.The positive ion modes and multiple reaction monitoring(MRM)mode were used in the analysis,and the analytes were quantified by external standard method.The 27 fungicides showed good linearities in the range of 0.02-200 μg/L,and the limits of detection(LOD)and the limits of quantification(LOQ)were 0.006-16.67 μg/kg and 0.02-55.5 μg/kg,respectively.The linear relative coefficients was greater than 0.995.The recoveries were in the range 70.02%-117.6% and the relative standard deviations(RSD)were ranged from 0.01% to 19.62%(n=3).The method has the advantages of simplicity,rapidity,high sensitivity and better purification effect.It is suitable for the rapid determination of the common fungicides in cereals,vegetables and fruits.3.A method for simultaneous determination of 27 new fungicides in cereals,vegetables and fruits using SPE-LC-Q-TOF/MS technique was developed.Samples were extracted with acetonitrile containing 1%(v/v)acetic acid,purified by solid phase extraction(SPE)with a Crabon/NH2 cartridge,eluted with acetonitrile-toluene(3:1,v/v),separated by a reversed phase C18 column,gradiently eluted with acetonitrile and 0.1% formic acid solution(Containing 5 mmol/L ammonium acetate),determined by LC-Q-TOF/MS and quantified by external standard method.A data base of the accurate mass numbers and a library which contains the 27 fungicides were established.The automatic retrieval of detection results was carried out according to the characteristics of the compounds,such as accurate mass,retention time,isotope peak distribution,isotopic ratios,and so on.Based on the above results,the qualitative identifications of the 27 new fungicides were accomplished without the contrast of standard substances.The results indicated that 27 new fungicides showed good linearities in the range of 0.02-300 μg/L,and the limits of detection(LOD)and the limits of quantification(LOQ)were 0.01-20 μg/kg and 0.02-100 μg/kg,respectively.The linear relative coefficients were greater than 0.995.The recoveries were in the range 71.8%-114% and the relative standard deviations(RSD)were ranged from 0.1% to 21.3%(n=3).The method has the advantages of simplicity,rapidity and high sensitivity.It is suitable for the rapid determination of the common fungicides in cereals,vegetables and fruits.更多还原