【作者】 伍伟民；

【导师】 谢增鸿；

【作者基本信息】 福州大学 ， 食品安全与药物化学， 2009， 博士

【摘要】 本论文主要研究了一些食品污染要素的加压毛细管电色谱分离分析方法，建立了记忆丧失性贝毒、酚类环境雌激素、环境激素类有机磷农药的加压毛细管电色谱分离测定新方法，并应用于贝肉、鸡蛋奶粉、果蔬等餐桌食品中的污染监测。本论文分为四章。第一章，重点介绍了加压毛细管电色谱技术分离原理与检测技术。加压毛细管电色谱是新近发展起来的一种高效微分离技术，结合毛细管电泳电渗流驱动的高效性与高效液相色谱溶质保留的高选择性，通过在毛细管色谱柱两端施加高压电场，依靠电渗流与压力流推动流动相，使中性和带电荷的样品分子根据它们在色谱固定相和流动相间吸附、分配平衡常数的不同以及电泳速率不同而达到分离分析的一种电分离模式。pCEC具有高分离效率、高选择性、分析速度快、试剂消耗少等突出优点。同时介绍了海洋贝类毒素与环境激素等分析对象。并归纳了有关加压毛细管电色谱技术在食品安全分析中应用的文献。第二章，通过加压毛细管电色谱紫外检测法，建立了对海洋赤潮生物毒素的重要种类之一、记忆丧失性贝类毒素的主要成分——软骨藻酸(domoicacid, DA)的一种新分离与定量分析方法。实验采用ODS反相填充柱，系统优化了流动相中的乙腈体积含量、缓冲液浓度和pH值、柱压压力、分离电压等影响软骨藻酸与基质分离的实验参数。软骨藻酸在1.0～100.0μg/mL范围内具有良好的线性关系，检出限为0.5μg DA/mL提取液（等于2.0μg DA/g贝肉，低于20μg DA/g贝肉的食品安全限量标准）。在三个水平浓度上进行加标回收率实验，平均回收率分别为83.4％，85.2％和86.4％，RSD分别为3.0％，2.3％和2.8％。利用该方法对三种经济贝类样品进行了分析。该新方法具有简单、重复性好、速度快、分析成本低等特点，对贝类样品中软骨藻酸的检测和监控具有一定意义。第三章，使用碳糊电极作为工作电极，建立了加压毛细管电色谱安培法同时分离测定五种重要酚类环境雌激素的新方法，并将方法应用于鸡蛋和奶粉食品样的分析。系统优化了双酚A、2,4-二氯酚、五氯苯酚、壬基苯酚和辛基苯酚的加压毛细管电色谱分离条件。在最优条件下，即：含60％体积乙腈和40％体积Tris缓冲液（5mmol L-1, pH8.0）的流动相；分离电压为+6kV；柱压压力为7.0MPa，五种重要酚类环境雌激素在22分钟内实现基线分离。实验对比了铅笔芯碳圆盘电极和碳糊电极对分离物的不同检测灵敏度，选择碳糊电极与+0.8V工作电位作为最优安培检测条件。在实际样品前处理中，采用基质固相分散法，并在三个水平加标浓度上获得从79.2%到102.6%的回收率。针对食品中重要酚类环境雌激素所建立的该方法灵敏度高、回收率结果令人满意。第四章，通过在流动相中添加电化学活性物质——3,4-二羟基苯甲胺氢溴酸盐（DHBA），建立了环境激素类非电化学活性有机磷农药的加压毛细管电色谱间接安培检测法。实验考察了流动相中添加剂种类的选择、DHBA浓度、安培检测工作电位对流动相本底电流以及有机磷农药倒峰峰高的影响。选择0.1mmol L-1DHBA添加到流动相中，选择0.9V (vs. Ag/AgCl)作为最佳安培检测工作电位。实验优化了加压毛细管电色谱对所选六种有机磷农药的分离条件，在最优分离条件下，即：流动相：50%v/v乙腈,50%v/v MES缓冲液(10mmol L-1, pH5.5),0.1mmol L-1DHBA；分离电压：+10kV；柱压：7.0MPa，泵流速：0.05mL min-1，安培检测工作电位：+0.9V，乐果、甲基对硫磷、乙基对硫磷、毒死蜱、甲基毒死蜱、敌百虫六种有机磷农药在15min内达到基线分离，检出限分别为2.0、2.5、0.5、0.5、0.2、2.5g mL-1。采用固相萃取法处理实际样品，蔬菜中的加标回收率从78.9%到87.2%，水果中的加标回收率从81.4%到98.6%。通过间接法，加压毛细管电色谱安培检测联用仪器的应用范围被进一步拓展，为果蔬食品中环境激素类有机磷农药残留的分离检测提供了一种新方法。更多还原

【Abstract】 In this thesis, some contaminators in foods were analyzed by pressurizedcapillary electrochromatography, and new methods related to amnesic shellfishpoisoning, phenolic xenoestrogens and organophosphorous pesticides wereestablished. The developed methods were also applied to the analysis of targetcompounds in shellfish tissues, eggs, milk powder, vegetables and fruits.There are four chapters in this thesis, and the main contents are listed asfollows:In chapter1, pressurized capillary electrochromatography (pCEC) performedby electroosmosis flow (EOF) combined with the forward and reverse pressure inthe separation process, is a recently developed micro-column electro-separationtechnique which combines the high efficiency of capillary electrophoresis andhigh selectivity of high performance liquid chromatography.In chapter2, a new method was developed to quantify domoic acid, thechemical responsible for Amnesic Shellfish Poisoning (ASP), by pressurizedcapillary electrochromatography. The effect of different experimental conditionson the separation of domoic acid and matrix solutes, such as the content ofacetonitrile in mobile phase, pH and concentration of buffer, supplementarypressure and applied voltage, were investigated. Under the optimal conditions, thepCEC method separated domoic acid from shellfish matrices within6min. Byusing supplementary pressure, bubble formation in the capillary column wascompletely suppressed. The method was repeatable, sufficient accurate andsensitive for rapid screening of domoic acid in shell seafood. In chapter3, pressurized capillary electrochromatography with end-columnamperometric detection using carbon paste electrode has been developed for theseparation and determination of five phenolic xenoestrogens in chicken eggs andmilk powder samples. Efficient separation of five analytes was performed bypCEC using a mobile phase consisting of60%v/v ACN and40%v/v Tris buffer(5mmol L-1, pH8.0),+6kV of applied voltage and7.0MPa of supplementarypressure. Detection limits of50,5,2,10, and20ng mL-1for pentachlorophenol,bisphenol-A,2,4-dichlorophenol,4-tert-octylphenol, and4-nonylphenol,respectively, were achieved using carbon paste electrode as working electrode and+0.8V as detection potential. After matrix solid phase dispersion extractionprocedure, mean recoveries ranged from79.2%to102.6%at differentconcentrations of phenolic xenoestrogens for spiked egg and milk powder sampleswere obtained.In chapter4, by adding3,4-Dihydroxybenzylamine hydrobromide (DHBA)in mobile phase, typical organophosphorous pesticides, which belong toenvironmental hormone and have no electroactivity, were separated anddetermined by pressurized capillary electrochromatography with indirectamperometric detection method. The kinds of additives with electroactivity werecompared. The effect of concentration of DHBA and working potential to thebackground current of mobile phase and negative peaks height were studied. Theconcentration of DHBA was selected as0.1mmol L-1, and the working potentialof amperometric detection was selected as0.9V (vs. Ag/AgCl). The optimalanalysis conditions for six organophosphorous pesticides were as follows: mobilephase:50%v/v ACN,50%v/v MES buffer (10mM, pH5.5),0.1mmol L-1DHBA, applied voltage:+10kV, supplymentary pressure:7.0MPa, pump flowrate:0.05mL min-1, electrode potential:+0.9V. The six organophosphorouspesticides, namely, dimethoate, methyl parathion, ethyl parathion, chlorpyrifos,chlorpyrifos-methyl, trichlorfon, were baseline separated within15min, and thelimits of detection were2.0,2.5,0.5,0.5,0.2,2.5g mL-1respectively. After solid phase extraction procedure, recoveries of vegetable samples were ranged from78.9%to87.2%, and that of fruits samples were ranged from81.4%to98.6%.The accuracy of the proposed method was good.更多还原