【作者】 李岩；

【导师】 庞国芳；

【作者基本信息】 燕山大学 ， 应用化学， 2013， 博士

【摘要】 本论文针对目前茶叶多残留分析中存在的基质效应问题，对不同产地和种类的茶叶基质效应进行了研究，同时建立了采用分析物保护剂补偿茶叶中农药多残留测定时基质效应的定量方法。以全国12个茶叶主产地的28种地理标志茶叶为研究对象，深入研究了不同种类和不同产地茶叶采用气相色谱-质谱（GC-MS）和气相色谱-串联质谱（GC-MS/MS）测定时的基质效应。首次采用化学计量学方法按照基质效应对茶叶进行分类：第一类是不发酵和轻微发酵茶叶样品；第二类为半发酵类茶叶样品；第三类为全发酵和后发酵茶叶样品。任何茶叶都可以作为其类别中的代表性茶叶进行基质匹配标准曲线的绘制。该研究结果为选择代表性茶叶配制基质匹配标准溶液提供了理论依据，同时代表性茶叶种类的应用可以在保证实验数据精准度的前提下，减少配制基质匹配标准溶液的数量，加快实验分析速度。评价了11种不同分析物保护剂在不同浓度以及不同组合的情况下对农药峰型、峰响应以及茶叶中农药添加回收率的影响，建立了GC-MS测定茶叶中186种农药多残留时的分析物保护剂补偿基质效应定量方法，填补了国内外空白。以甘油三酯和D(+)-核糖酸-γ-内酯两种保护剂组合（进样浓度均为2mg/mL）进行定量分析时，可达到充分补偿茶叶样品基质效应的作用。方法快速简便，具有较好的灵敏度和精密度，同时定量限可达到国内外药物残留分析限量的要求。通过对仪器稳定性的考察，发现添加分析物保护剂后，对仪器系统稳定性无不利影响，多次进样后系统仍然保持良好的灵敏度和精密度，可降低色谱系统的维护频率。同基质匹配标准定量方法相比，分析物保护剂定量方法在保证实验准确度的同时，操作更为简便，可提高分析速度，同时降低仪器系统维护频率。通过相同的评价方法，建立了GC-MS/MS测定茶叶中205种农药多残留时的分析物保护剂补偿基质效应定量方法，结果表明甘油三酯和D(+)-核糖酸-γ-内酯两种保护剂组合（进样浓度均为2mg/mL）对茶叶中农药多残留分析时基质效应补偿效果最好。同时建立的方法的灵敏度、准确度、精密度以及标准曲线和线性范围等指标均符合分析要求，分析物保护剂的应用可提高GC-MS/MS系统的耐受性。GC-MS/MS定量方法采用的分析物保护剂种类和浓度同GC-MS相同，也就是说检测器的不同并未对分析物保护剂的种类造成影响，GC-MS和GC-MS/MS在茶叶分析时的基质效应主要是由于气相色谱系统造成的。更多还原

【Abstract】 To better understand the matrix effects in pesticide multi-residue analysis in tea, matrixeffects of tea with different origin and type were studied, and methods using the combinationof analyte protectants to overcome matrix effects in GC-MS and GC-MS/MS analysis ofpesticide residues in tea matrix were proposed.In this thesis,28varietals of tea which are the products of national geography symbolwere selected to be studied for the matrix effects in GC-MS and GC-MS/MS analysis.Chemometric methods were used to classify the teas. Tea samples were divided into threeclusters: the first cluster consisted of not fermented and slightly fermented tea samples; thesecond cluster were composed of semi-fermented tea samples; the third cluster consisted offully fermented and post-fermented teas. Any type of tea can be chosen from each cluster ascorresponding representative matrix within this cluster to make matrix-matched solutions. Theresult provides a good theory basis for the selection of representative matrix for tea. Therepresentative tea matrix could simplify the operation of the experiment while guarantee theaccuracy of the experiment.Different APs were evaluated to find the most suitable ones for improvingchromatographic quality of the signal. The influence of the APs on the peak shape andabundance were studied. The concentration and combination of different APs were alsoevaluated. A method to compensate for the matrix effects in the determination of186pesticideresidues in tea by GC-MS using analyte protectant was proposed. A mixture of triglycerol andD-ribonic acid-γ-lactone (both at2mg/mL in the injected samples) was found to be the mosteffective in improving the chromatographic behavior of186pesticides. The proposed methodwas quick and convenient, with good sensitivity and precision and the limit of quantificationcould reach the residue analysis requirements. The influence of the APs combination on thestability of the instrument was also investigated. The combination of APs resulted inruggedness improvment and consequently, reduced the maintenance for GC. As compared tomatrix-matched standardization, the analyte protectant approach offers a more convenientsolution to the problems associated with calibration in routine analysis of pesticide residuesand reducing need for frequent maintenance. A GC-MS/MS analytical method was developed for simultaneously determining205pesticides in tea matrices using analyte protectants to counteract the matrix-induced effect bythe same evaluation method of GC-MS. A mixture of triglycerol and D-ribonic acid-γ-lactone(both at2mg/mL in the injected samples) was found to be the most effective APs. Thelinearity, sensitivity, accuracy and precision of the method were validated. The combination ofAPs improved the ruggedness of GC-MS/MS. The category and concentration of the APs inthe proposed methods of GC-MS and GC-MS/MS were the same which means that thedifference of the detector is not the main influence of the matrix effect. The matrix effects oftea are mainly caused by the gas chromatography system.更多还原