【作者】 王娜妮；

【导师】 朱岩；

【作者基本信息】 浙江大学 ， 化学， 2014， 博士

【摘要】 离子色谱自二十世纪七十年代问世以来得到了长足的发展,已经成为各种离子化合物最有效的分析手段。但是复杂基质的分析一直是离子色谱领域的挑战,建立高灵敏度、高选择性的新型离子色谱分析体系具有非常重要的意义。本工作通过柱切换技术、新型色谱固定相以及选择性检测法等途径,建立了快速分析复杂基体中痕量组分的新型离子色谱体系,主要研究内容由以下七章节组成。第一章：介绍了离子色谱在复杂基体分析中的研究进展。从样品前处理、色谱固定相和检测方法三个方面系统性介绍了离子色谱法在去除基体干扰和分析痕量组分方面的应用。第二章：建立了离子色谱柱切换系统,应用于高纯硫酸盐试剂中痕量杂质的分析。第一次分离后,抑制器可使流动相失去淋洗能力,杂质离子(C1-)在富集柱中保留富集,而大多数基体离子(S042-)进入废液；第二次分离后,杂质离子与仅存的少数基体离子实现完全分离。方法检出限为10.0μg/L,线性范围为30-100μg/L。本方法改进了传统柱切换法需要两台泵的缺点,只需要一台泵就能实现高浓度基体中痕量组分测定,成功地应用于多种硫酸盐中杂质离子cl-的分析,操作简便,灵敏度高,可用于高纯试剂的质量控制。第三章：建立了循环离子色谱系统,应用于多种复杂基体中痕量物质的分析。其中包括：高盐溶液中的痕量亚硝酸根离子的分析、氯碱电解液中痕量杂质的分析和海水中的多种微量无机阴离子的分析。传统柱切换法只能实现一次基体消除,存在难以确定柱切换时间窗、基体消除不完全等缺点。本工作使用了循环离子色谱系统,可以同时实现多次消除基体和循环富集待测离子。在高盐溶液中的痕量亚硝酸根离子的分析中,方法的检测限是3.1μg/L, RSD值小于1.0%；对于氯碱电解液中痕量杂质的分析,方法线性范围为0.01-1.0mg/L,检出限是2.2μg/L, RSD值小于1.3%；对于环境样品海水中的微量无机阴离子的分析,该方法测定了海水中多种无机阴离子的含量(F-, N02-, N03-, Br-, SO42-, PO43-),具有较宽的线性范围(0.05-25.0mg/L),较好的重复性(RSD<4%)和较低的检测限2.3-23.6μg/L。第四章：建立了基于整体柱分离的离子色谱-柱后衍生紫外检测分析体系。应用于食品和矿泉水中的溴酸盐分析。分离柱为自制的阴离子交换整体柱,基质为聚丙烯酸酯,离子交换基团为季铵基团。该整体柱具有良好的通透性、较低的柱压、较好的机械强度和较强的分离性能,能够很好的分离食品等复杂基质中的痕量溴酸根离子。本工作采用碘化钾为柱后反应试剂,用紫外分光光度法检测痕量溴酸盐的含量。该方法具有重现性好(RSD<1.7%)、灵敏度高(检出限为1.5μg/L)和选择性佳等优点。第五章：建立了基于碳纳米管改性整体柱分离的毛细管离子色谱分析系统,测定了环境水样中的5种痕量无机阴离子的分析(IO3-, BrO3-, NO2-, Br-, NO3-)。利用碳纳米管比表面积大、机械强度高、易化学修饰等优点,采用碳纳米管掺杂改性聚丙烯酸酯整体柱基质,在毛细石英管中通过原位聚合反应,制备了一种新型的阴离子交换色谱固定相。结果表明,碳纳米管的加入能够提高色谱柱的分离能力。本系统采用整体柱为分离柱,紫外分光光度计作为检测器搭建了毛细管离子色谱系统,用于分析泉水中的痕量无机阴离子,方法检出限为0.11-0.17mg/L,线性范围为0.2-100.0mg/L。更多还原

【Abstract】 In recent years, ion chromatography has been an important tool for the analysis of ion species. This method has many advantages, such as high sensitivity, good selectivity and wide applications. However, analysis of complex matrices is still a challenging task. In this work, novel ion chromatography systems were established and applied to the analysis of complex matrices.In Chapter1, the recent development of the analysis of complex matrices by ion chromatography was reviewed. The chapter focused on three parts:the sample pretreatment, stationary phase and detection methods. The matrix elimination and trace analysis were pointed out.In Chapter2, a novel column-switching ion chromatography system was established and applied to the determination of trace impurity in sulfuric salts. The trace impurity (chloride) could be concentrated in the concentrator column after the first separation. Meanwhile, the matrix (sulfate) flowed to the waste. The limit of detection was10.0μg/L. The linear range was30-100μg/L. The developed method would be a promising method for the analysis of trace chloride in high-purity reagents.In Chapter3, a novel cycling-column-switching ion chromatography system was developed for the analysis of trace nitrite in high salt matrices. This system included a pump, a single eluent, two valves and a conductivity detector. Both matrix elimination and online concentration could be achieved by this method. The target anions were eluted from the analytical columns to the concentrator column circularly. Chloride matrix was eliminated completely. The method was successfully applied to the determination of trace nitrite in the chloride matrix. It was also applied to analyze trace chlorate in chloride matrix. The results demonstrated that this system was of advantages such as high sensitivity, facile automation and simple sample pretreatment, which was a promising approach for environmental researches and chlor-alkali industry. The cycling-column-switching ion chromatography system was then developed for the analysis of low-level inorganic anions in seawater. This system included a single pump, two valves, a suppressor and three columns. Using this method, six inorganic anions were eluted from the separation column to the concentrator column circularly. The matrices flowed to the waste. The linear range was0.05-25.0mg/L. The limits of detection were in the range of2.3-23.6μg/L. The RSD values were below4%. The method was convenient and practical for the analysis of trace anions in high-salinity environmental samples.In Chapter4, a selective chromatographic method was developed for the analysis of trace level bromate in food sample and drinking water. This method was based on a poly (glycidyl methacrylate-co-ethylene dimethacrylate) monolithic column, which was prepared by in-situ polymerization and then modified with quaternary amine groups. Morphology of the stationary phases was investigated by scanning electron microscopy. Permeability and mechanical stability of the column were both good. Bromate was detected after post-column reaction with potassium iodide at352nm. The parameters affecting the detection limit were studied in detail.In Chapter5, a novel monolithic stationary phase containing multiwall carbon nanotube was prepared by in-situ polymerization of methacrylate monomers in a silanized capillary. These columns were used in the separation of five inorganic anions. Carbon nanotube played an important role in the chromatographic separation. Both the exchange capacities and column efficiencies were improved by adding carbon nanotube in the monoliths.更多还原