二氧化钛纳米管在痕量元素分离富集及等离子体质谱检测中的应用

发布时间：2019-02-13 13:55

【摘要】：近些年来,随着全球工业化进程的加快,环境污染问题日益引起人们的极大关注。如何快速、高效、准确地检测环境中的污染物,已成为当前人们研究的重要课题之一。然而,值得注意的是在实际样品分析中,基体成分复杂,待测组分含量低,基体干扰严重,采用现有仪器对试样进行直接测定常常遇到困难。因此,为了获得准确的分析信息,往往在测定前需要对待测样品进行的预处理,以改善方法的分析性能,从而获得满意的分析结果。固相萃取作为一种分离预富集技术,因其具有操作简便快速、有机溶剂消耗少、萃取效率高、测定结果重现性好、处理过程无乳化现象、能处理小体积试样、吸附材料可循环利用以及便于与其它检测仪器实现联用等特点,广泛应用于样品的分离预富集过程中。在固相萃取过程中,固相萃取剂的选择至关重要,因而,寻找新型的、萃取效率高的萃取剂是当今分析化学学科领域关切的重要话题。纳米材料具有比表面积大,表面能和表面结合能高,表面原子因缺少相邻原子,易于与金属原子结合,趋于饱和,化学活性比较高,因而对金属离子具有较强的吸附性能,是一种颇具潜力的固相萃取材料。二氧化钛纳米管作为一种新型吸附材料,相较于一般的纳米二氧化钛粉体,具有独特的管状结构、更大的比表面积和更强的吸附性能,是一种颇具应用前景的固相萃取剂。然而,采用二氧化钛纳米管作为固相吸附剂分离富集金属离子的研究报道较少。本文采用二氧化钛纳米管为固相萃取吸附剂,以电感耦合等离子体质谱为检测手段,系统地研究了动态条件下二氧化钛纳米管对痕量元素的吸附性,并对影响待测物吸附和洗脱的主要因素进行优化选择,将所建立的分离富集与分析方法应用于实际样品中痕量元素的测定。主要研究内容如下:(1)以ICP-MS为检测手段,二氧化钛纳米管作为固相萃取吸附剂,研究了二氧化钛纳米管对重金属铊的吸附性能,考查pH值、进样流速、进样体积、干扰离子、洗脱剂体积、流速和浓度等因素对分离富集的影响,并将所建立的方法应用于实际样品中痕量铊的分析。(2)以二氧化钛纳米管作为固相萃取吸附材料,将微柱分离富集与ICP-MS检测技术联用,对金属金在二氧化钛纳米管上的吸附行为进行了探讨,考察了影响其分离富集和测定的主要因素,并将所建立的方法应用于生物和环境样品的分析中。
[Abstract]:In recent years, with the acceleration of global industrialization, environmental pollution has attracted more and more attention. How to detect pollutants quickly, efficiently and accurately has become one of the most important research topics. However, it is worth noting that in the actual sample analysis, the matrix composition is complex, the content of the components to be measured is low, and the matrix interference is serious, so it is often difficult to use the existing instruments to measure the samples directly. Therefore, in order to obtain accurate analysis information, it is often necessary to treat the sample pretreatment before determination to improve the analytical performance of the method and obtain satisfactory analytical results. Solid-phase extraction (SPE) is a separation and preconcentration technique, because of its advantages of simple and rapid operation, low consumption of organic solvent, high extraction efficiency, good reproducibility of determination results, no emulsification in the treatment process, and it can be used to treat small samples. The adsorption materials can be recycled and can be easily combined with other detection instruments, so they are widely used in the process of sample separation and preconcentration. In the process of solid phase extraction, the choice of solid phase extractant is very important. Therefore, it is an important topic in the field of analytical chemistry to find a new extractant with high extraction efficiency. The nanocrystalline materials have large surface area, high surface energy and surface binding energy. The surface atoms are easy to bind to metal atoms, tend to saturation and have high chemical activity because of the lack of adjacent atoms, so they have strong adsorption properties to metal ions. It is a potential solid phase extraction material. As a new adsorption material, titanium dioxide nanotubes have a unique tubular structure, larger specific surface area and stronger adsorption performance, which is a promising solid phase extraction agent. However, there are few studies on the separation and enrichment of metal ions using titanium dioxide nanotubes as solid-phase adsorbent. In this paper, the adsorption of trace elements on titanium dioxide nanotubes under dynamic conditions was systematically studied by means of inductively coupled plasma mass spectrometry (ICP-MS) and solid phase extraction (SPE) adsorbents of titanium dioxide nanotubes. The main factors affecting the adsorption and elution of the samples were optimized, and the established separation, enrichment and analysis methods were applied to the determination of trace elements in actual samples. The main contents are as follows: (1) the adsorption properties of titanium dioxide nanotubes for heavy metal thallium were studied by using ICP-MS as detection method and titanium dioxide nanotubes as solid phase extraction adsorbent. The pH value, injection velocity and volume of samples were investigated. The effects of interference ions, volume of eluent, flow rate and concentration on separation and enrichment were investigated. The method was applied to the analysis of trace thallium in practical samples. (2) Titanium dioxide nanotubes were used as solid phase extraction adsorption materials. The adsorption behavior of metal gold on titanium dioxide nanotubes was studied by combining microcolumn separation and enrichment with ICP-MS detection technology. The main factors affecting the separation, enrichment and determination of gold on TiO2 nanotubes were investigated. The established method was applied to the analysis of biological and environmental samples.
【学位授予单位】：武汉轻工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O657.63;TQ134.11

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