【作者】 黄玉安；

【导师】 周方钦；

【作者基本信息】 湘潭大学 ， 分析化学， 2003， 硕士

【摘要】 本文在查阅大量中外文献资料基础上，通过深入、系统的实验研究，初步弄清了稀散金属元素镓与锗的分离、富集行为及机理，并将此方法应用于原子吸收光谱法的测定；建立了火焰原子吸收测定此类金属元素简单，实用，高灵敏度的方法。探讨了镓、锗元素在石墨炉原子吸收光谱中原子化行为及各种不同基体的作用效果和机理。深入研究镓原子化的各种影响因素的作用机制，提出了有一定普遍性的规律，优化了各项参数，找到了石墨炉原子吸收光谱法测定此类金属元素的高灵敏度、抗干扰的有效方法。一方面，本文对湖南省内稀散元素的生产和矿产资源评估与综合利用有一定的应用价值；在另一方面，对这类元素的分离富集机理和在其原子吸收光谱中的原子化规律研究有理论意义。全文共分三章。第一章报道了磷酸三丁酯萃取—火焰原子吸收法间接测定植物及矿物样品中痕量锗的新方法。锗与钼酸铵在0.3mol·L^-1的硝酸介质中形成稳定的锗钼杂多酸，并能被磷酸三丁酯萃取，有机相直接进样测定钼而间接测定锗。最优化了本方法的各种化学和仪器参数。对比研究磷酸三丁酯萃取前后的红外光谱后，对在本试验条件下的萃取机制作了推测。此法特征浓度为21.86ng·mL^-1／1％吸光度，相对标偏差RSD（N=11）为4.6％，加标回收率为97.6％—101.2％，线性范围为200 ng·mL^-1—2000 ng·mL^-1，线性回归方程为A=0.2668C-0.0243，相关系数为r=0.9986。第二章研究并比较了不同基体改进剂，不同涂层对镓在热解石墨管中原子化的影响。着重研究了以硝酸镍为基体改进剂，以涂钼热解石墨管为原子化器中镓的原子化机理，探讨了镓在各种环境中不同的原子化途径，提出了具有一定普遍性的原子化规律。优化了各项参数，找到了一种测定复杂样品中痕量镓的新方法。该方法较前人的方法在多方面有提高。方法特征量为2.12×10^-11g，检出限为1.4×10^-10g，相对标偏差RSD≤3.6％（n=11），声五安矛楷赓元清尉分护琦‘寡奥万为资真硕.子公戎法曾君翻定时研夕之样品回收率97.4一102.7%。 第三章报道了以强碱性阴离子交换树脂（717氯型）为固定相，用离子交换色谱法使稼选择性吸附并与常见干扰金属元素分离。富集在色谱柱上的嫁以蒸馏水洗脱并用原子吸收光谱法进行测定。嫁的回收率为95.2一99.9%。同时研究其富集分离的优化条件，包括柱床的填充特性，上柱形态，洗脱液及洗脱条件的选择等。进一步研究树脂在交换前后的红外光谱，并对离子交换作用的机制作了初步探讨。此方法己用于实际样品的分析并取得了良好的结果。更多还原

【Abstract】 On the foundation of numerous references, the behavior and mechanism about separation and preconcentration of the rare disperse metals, such as gallium and germanium, have been checked respectively; in addition, the method has been applied to determine the metals by atomic absorption spectrosocopy(AAS). Furthermore, the effects and the mechanism of different matrix acting on gallium in the graphite furnace of AAS, with the behavior on gallium atomization, have been discussed in detail.This paper consists of three chapters.In chapter 1. The effects on gallium atomization in the pyrogenated graphite tube imposed by different martix modifier and different coating was detailedly discussed in this paper. On this basis, the mechanism of gallium atomization in the moiybdenum-coated pyrogenated graphite tube using Ni(NO3)2 as martix modifier was studied furthermore; in addition, the parameters of the operation were optimized ; and as a result, a new method improved in many aspects was developed to detect trace gallium in complicated sampler. The outcomes of practical applications indicated that the method can satisfy the requests of analysis and that the manipulations were simple to achieve. The characteristic content, the detection limit, the adding recoveries were 2.12× 10-11 g , 1.4× 10-10g , 97.4-102.7% respectively and the relative standard deviation was less than or equal to 3.6%(n=11).In chapter 2. A novel new method was described for the indirect determination of trace germanium in fly ash based on the extraction using TBP by FAAS. The steady heteropolymobdate of germanium was formed in 0.3mol/L nitrate and was extracted into TBP phase; afterwards, indirect determined germanium was achieved with determination of molybdenum in TBP phase by FAAS. The RSD(n=ll), the adding recoveries, the characteristic content , and the linear range of the method were 4.6%, 97.6%-101.2%, 21.86 ng mL-1/0.0044A, 200ng.mL-1- 2000 ng.mL-1 respectively. The equation of linear regression was A=0.2668C-0.0243 with the r=0.9986.In chapter 3. By means of ion exchange chromatography, the micro amount of gallium was separated from common metal elements successfully, using strong base type anionic resin as stationary phase. Gallium preconcentrated in chromatographic column was eluted with distilled water, and then separation and determination by AAS were carried out. The recoveries of gallium was 95.2% ~99.9%. Simultaneously, the optimized conditions of separation and preconcentration, including the specific properties of packed column the form of gallium packed in exchanger the verity of eluent and the factors of eluate have been discussed respectively. The whole method has been applied to analysis the practice sample with satisfactory result.In a word, by numerous systematic and scrupulous experimental research, the method about selectivity separation andpreconcentration of scatter elements had been found. After that, the method was contacted with AAS. Thus, a simple and practice method to detect the metals by AAS and GFAAS have been established successfully with high sensitivity. All these work make the methods full of practical and theoretical value.更多还原