【作者】 王旭东；

【导师】 吴晓静；

【作者基本信息】 合肥工业大学 ， 应用化学， 2009， 硕士

【摘要】 铊由于其毒性已经被认为是一种对环境有重要影响的元素。但是在自然界中铊的含量低于μg·g^-1的水平,各种对铊元素的选择、分离、富集、净化和检测方法研究已成为一个有挑战性的课题。在分析和环境化学中对痕量铊元素的高灵敏度和可靠的检测方法具有重要意义。动力学分析法是利用化学反应速率和反应物浓度、催化剂之间的关系而进行定量分析的方法。而催化动力学法具有灵敏度高、选择性好、设备简单、操作简单的特点,是测定微量金属元素的有效方法之一。本论文研究了铊对几种化学发光反应的影响,建立了一系列测定铊的新方法,并对其可能的反应机理进行了探讨。主要的研究内容如下:（1）基于铊对鲁米诺-H₂O₂体系的催化作用,据此建立了催化动力学光度法测定痕量铊（Ⅰ）的新方法。系统地考察鲁米诺反应体系随温度、时间的变化、共存离子等因素对测定结果的影响,确定了测定的最佳条件。测定铊（Ⅰ）的线性范围为0.05～0.2μg·mL^-1,工作曲线的线性方程为ΔA=0.365+0.088C(μg·mL^-1)（相关系数r=0.9989）,检出限为0.0078μg·mL^-1。用于矿石中痕量铊的测定,其RSD为1.34%,加标回收率在98%～102%之间。（2）在第一部分的基础上,利用配备了紫外检测器的高效液相色谱仪来测定痕量铊,建立了一种测定痕量铊的新方法。这种新的方法不仅结合了高效液相色谱的分离性能和化学发光反应的高灵敏度,而且条件简单。三种不同种类的表面活性剂被加入到鲁米诺-H₂O₂体系中,分别为溴化十六烷基三甲基铵（CTMAB）（阳离子型表面活性剂）、十二烷基磺酸钠（SDS）（阴离子型表面活性剂）、吐温80（非离子型表面活性剂）。在最佳条件下,测定铊（Ⅰ）的检测限为0.0073μg·mL^-1,6次测定0.04μg·m^-1铊的标准偏差为低于4.0%,检测的线性范围为0.02～0.1μg·mL^-1。（3）研究了紫外光对铊-光泽精-H₂O₂体系的光化学催化作用,建立了测定痕量铊的新方法。系统地考察光泽精反应体系光化学催化作用、光照时间的变化、共存离子等因素对测定结果的影响,并探讨了该体系光化学催化作用可能的机理,确定了测定的最佳条件。测定铊（Ⅰ）的线性范围为0.05～0.31μg·mL^-1,工作曲线的线性方程为ΔA=0.0854+0.0892C(μg·mL^-1)（相关系数r=0.996）,检出限为0.0081μg·mL^-1。用于矿石中痕量铊的测定,其RSD为3.27%,回收率在97%～103%之间。更多还原

【Abstract】 Thallium has been identified to be an environmentally significant element because of its toxic effects.But as the concentration of Thallium in the nature is belowμg·g^-1 level,the development of new methods for selective separation, preconcentration,purification and determination of this metal continues to be a challenging problem.The need for highly sensitive and reliable method for the determination of ultratrace level Thallium has been recognized in analytical and environmental chemistry.The kinetic analytical methods are made using the relations among chemical reaction rates,reactant concentrations and catalysts.The catalytic kinetics has high sensitivity,excellent selectivity,inexpensiye instruments and simple operation.It is one of the effective methods for detecting trace metals.In this thesis, the measurements of trace Thallium（Ⅰ） were established based on its catalytic effect on the chemiluminescence reaction and their reaction mechanisms were also discussed.The main contents of the present work are as follows:（1） A new catalytic kinetic spectrophotometric method was developed for the determination of Thallium（Ⅰ） based on its catalytic effect on the system of Luminol and hydrogen peroxide.The temperature and reaction time of the system and its effect of coexisting ions were also investigated in detailed.The linear range of the method was 0.05～0.2μg·mL^-1 for Thallium（Ⅰ）.The linear equation wasΔA=0.365+0.088C(μg·mL^-1)（r=0.9989） and the detection limit was 0.0078μg·mL^-1.It has been applide to the determination of trace Thallium（Ⅰ） in mineral sample with RSD of 1.34%and recovery of 98%～102%.（2） At the first part of the foundation up,using a high-performance liquid chromatography equipped with the UV detector to the determination of trace thallium, set up a new determination of trace thallium Ways.This new method not only combines high-performance liquid chromatography separation performance and the chemiluminescence reaction of high sensitivity,and easy conditions.Three different kinds of surfactants,cetrimonium bromide（CTMAB）,sodium dodecyl sulphate （SDS）,and Tween-80,are also investigated to improve the detection sensitivity.In optimum conditions,a highly selective and sensitive method for detecting trace Thallium（Ⅰ） has been established.The detection limit is 0.0073μg·mL^-1,the relative standard deviation for six determinations of 0.04μg·mL^-1 Thallium（Ⅰ） is less than 4.0%, and the linear range of determination is 0.02～0.1μg·mL^-1.（3） A new method for the determination of trace element thallium was proposed based on the catalysis of Thallium（Ⅰ） on the photochemical reaction of lucigenin and hydrogen peroxide whit UV radiation.The light sources,radiation time of the system, a possible mechanism and its effect of coexisting ions were also investigated in detailed.The linear range of the method was 0.05～0.3μg·mL^-1 for Thallium（Ⅰ）.The linear equation wasΔA=0.0854+0.0892C(μg·mL^-1)（r=0.996） and the detection limit was 0.0081μg·mL^-1.By using the method in the determination of trace Tl（Ⅰ） in mineral sample,the RSD and recovery were 3.27%and 97%～103%,respectively, the results had shown that the method was satisfactory.更多还原