【作者】 侯志广；

【导师】 袁星；

【作者基本信息】 东北师范大学 ， 环境科学， 2013， 博士

【摘要】 针对目前人参及其制品农药残留的检测品种少，前处理方法落后，灵敏度和专属性较差，同时农药残留检测中存在的“假阳性”问题，本论文采用GC-MS和HPLC-MS-MS方法，系统研究了19种有机氯农药，9种β-甲氧基丙烯酸酯类农药和8种人参中常用农药的残留分析方法。采用乙腈提取、弗罗里硅土固相萃取柱净化建立人参及其制品中19种有机氯GC-MS快速检测方法。方法检测效率高、操作简单、快速。在空白样品中，19种有机氯农药的回收率在70.0%～117.0%之间，精密度（RSD）为1.4%～19.7%。各组分定量限在0.01～0.04mg/kg之间。采用乙腈进行匀浆提取，经弗罗里硅土固相萃取柱对样品提取液进行净化、富集，建立了一种灵敏、专属的GC-MS分析方法，用于检测人参中9种β-甲氧基丙烯酸酯类农药的残留量。在空白人参样品中，添加β-甲氧基丙烯酸酯类杀菌剂的平均回收率在79.9%～106.7%之间，精密度（RSD）为0.5%～12.1%。各组分定量限在0.01～0.025mg/kg之间。通过对QuEChERS方法的优化，建立了8种人参常用农药的QuEChERS提取，液相色谱-质谱/质谱MRM模式（HPLC-MS/MS MRM）定量方法。所建立的方法快速、简单、绿色环保。8种农药在三个添加水平下（0.01mg/kg、0.05mg/kg、0.5mg/kg），回收率在85.9%~102.5%之间，符合分析要求，精密度（RSD）<15%，线性范围在5ng/mL~250ng/mL之间，定量限在0.1μg/kg~10μg/kg之间。同时评价了8种农药在人参中的基质效应，结果表明，绝大多数农药在基质中有不同程度的基质增强效应。利用GC-MS建立了嘧菌酯和醚菌酯在人参和土壤环境中的残留分析方法。嘧菌酯添加浓度在0.01mg/kg~0.5mg/kg范围内，回收率在98.2%~103.2%之间，RSD小于5%。醚菌酯添加浓度在0.05mg/kg~2.0mg/kg范围内，回收率在90.5%~100.3%之间，RSD小于10%。利用该方法研究了嘧菌酯、醚菌酯在人参植株及土壤上的残留动态及最终残留量，实验结果表明，嘧菌酯和醚菌酯在人参植株的原始沉积量分别为10.835mg/kg~43.953mg/kg和2.489mg/kg~3.245mg/kg，人参植株中农药半衰期分别为0.7d~2.0d和6.9d~15.1d，都为易降解农药，到施药后30天，农药残留降解率超过65%。土壤中半衰期稍长，分别为2.5d~3.2d和8.8d~14.3d。针对嘧菌酯和醚菌酯开展了不同施药次数、不同施药剂量、不同安全间隔期等复合因子条件下的GAP农药残留田间试验和室内研究。施药剂量、施药次数和采收时间对最终残留量都有影响，其中嘧菌酯农药残留量受采收间隔影响较大，醚菌酯受施药剂量影响较大。参考韩国和其他相关限量要求，末次施药后3天，人参中嘧菌酯和醚菌酯的残留量低于残留限量要求，建议安全间隔期3天。嘧菌酯和醚菌酯在人参上安全使用准则：建议我国制定嘧菌酯在人参上的MRL值为0.5mg/kg，安全间隔期为3天，250g/L嘧菌酯悬浮剂用量不超过225.0a.i.g·hm-2，用药次数不超过4次；醚菌酯在人参上的MRL值为0.1mg/kg，安全间隔期为3天，50%醚菌酯水分散颗粒剂用量不超过150.0a.i.g·hm-2，用药次数不超过4次。更多还原

【Abstract】 Mass spectrometry （MS） is becoming an indispensable technique in food andenvironmental studies. In the research, gas chromatography mass （GC-MS） and liquidchromatography mass （LC-MS） were used to study the fate of pesticide residues in ginsengand environmental samples. Target analytes relevant to human and environmental health wereselected in the studies, which include19trace organochlorinated pesticides,9strobilurinfungicides and8commonly used pesticides in ginseng.A new gas chromatographic-mass spectrometry method was developed for simultaneousmeasurement of19trace organochlorinated pesticide residues in ginseng. The ginsengsamples were extracted by acetonitrile, and the extracts were cleaned up with a column of6mL Florisil by solid phase extraction. The19organochlorinated pesticides were separatedthrough DB^-17MS capillary column and were measured by GC-MS. The recoveries rateranged from70.0%to117.0%. When0.05².00mg/kg pesticides were added, the relativestandard deviations of detections were ranged from1.4%to19.7%, and the limit ofdetermination was lowered to0.010⁰.040mg/kg. This method is rapid, sensitive and suitablefor the analysis of organochlorinated pesticide residues in ginseng.A sensitive and selective method was developed for the determination of residuesincluding azoxystrobin, dimoxystrobin, fluoxastrobin, kresoxim-methyl, e-metominostrobin,picoxystrobin, mepanipyrim, pyraclostrobin and trifloxystrobin in panax. The extract wascleaned up by solid-phase extraction （SPE）, and the elute solution was evaporated andresoluted in a definite volume. Determination and confirmation were made by gaschromatography-mass spectrometry at selective ions monitoring mode with external standardmethod. The average recoveries spiked samples at the three concentrations of0.025,0.25,2.0mg/kg ranged from79.9%to106.7%with relative standard deviation ranged from0.5%to12.1%. The limits of detection were0.01⁰.025mg/kg in variesou matrixes.QuEChERS methods for the determination of8pesticides in ginseng by highperformance liquid chromatograpy electrospray tandem mass spectromtry （HPLC-MS/MS） inthe mode of MRM were described. The recoveries were ranged from85.9%to102.5%withrelative standard deviation （RSD）<15%. The calibration curve linear with coefficient rangedfrom5ng/mL to250ng/mL, in the concentration level of0.01mg/kg、0.05mg/kg、0.5mg/kg,the LOQ for detection for the8pesticides were ranged from0.1μg/kg to10μg/kg. In thisstudy, matrix effect of8pesticides in ginseng was evaluated. Results indicated that matrixenhancement effects were showed in the most of the pesticides in some extent. In the whole, the developed methods are quick, simple and environment-friendly.To evaluate the risk of pesticide residues, the analytical gas Chromatography-massmethod for determine residues of azoxystrobin and kresoxim-methyl in ginseng and soils wasdeveloped, and the dynamics in ginseng and environment were studied in this paper.The limit of detection of azoxystrobin by GC-MS was1×10^-12g. The limit ofquantification of azoxystrobin by GC-μ-ECD was0.01mg·kg^-1, the recoveries of the methodwere98.2^-103.2%,99.6^-102.8%and100.2^-101.9%in soil, plant and ginseng.The limit of detection of kresoxim-methyl by GC-MS was1×10^-12g, the limit ofquantification of kresoxim-methyl by GC-MS was0.05mg·kg^-1, the recoveries of the methodwere92.2^-100.3%,90.5-94.8%and91.9^-100.3%respectively in soil, plant and ginseng.The residues dynamics of these pesticides in ginseng and soil were studied. The dynamicequations and half-lives were obtained. Suggestions about safety application of thesepesticides and the MRL of these pesticides in ginseng were put forward based on the results.From2008to2011, a series of GAP field trails, in different dose, different applicationtimes, and different harvest intervals time, were carried out in JiLin and BeiJing on twopesticides. The results showed that the original residue level of azoxystrobin andkresoxim-methyl were10.835⁴3.953mg/kg and2.489³.245mg/kg respectively in ginsengplant; the half-lives were0.7².0days and6.9¹5.1days respectively. They are all easy to bedegradated, and after30days,65%of the pesticides were degradated. In the soil, thehalf-lives were2.5³.2days and8.8¹4.3days respectively. The residue of azoxystrobin inginseng is influenced by the interval time directly, but kresoxim-methyl is influenced by theinterval dose. According to Korea guidance, the residue of azoxystrobin and kresoxim-methylare following the limit requirement after applying the azoxystrobin and kresoxim-methyl for3days. So the safety interval is3days.更多还原