原子荧光测汞仪的研制及多元素原子荧光同时测定方法研究

【作者】 李日升；

【导师】 阎宏涛；

【作者基本信息】 西北大学 ， 分析化学， 2012， 博士

【摘要】 随着全球经济的飞速发展,人口的持续增长,环境日益成为人们极大关注和研究的重要问题。重金属是环境中有毒有害污染物之一,研究建立快速、灵敏、准确的重金属分析检测方法和技术,对于环境监测及保护具有十分重要的意义。原子荧光光谱法具有测定灵敏度高、检出限低,无基体干扰等特点。已应用于As、Sb、Hg等十多种重金属元素的分析测定。本学位论文进行了原子荧光测汞仪和多元素原子荧光同时测定方法的研究。研制成功了高灵敏原子荧光测汞仪,原子荧光固体直接进样装置,提出了双化学蒸气发生系统,研究建立了多元素原子荧光同时测定方法。应用于不同样品中Hg、As、Sb、Se、Pn、Sn、Cd的分析测定,取得了满意结果。本文包括七个部分：1.绪论概述了原子荧光光谱法的发展历史,基本原理,仪器装置及其应用,并对原子荧光光谱法的发展进行了展望。2.高灵敏原子荧光测汞仪的研制采用光纤光束传导,自主设计的暗室原子化系统和金汞齐富集装置,成功地研制了高灵敏原子荧光测汞仪。其主要技术指标已达到(某些指标优于)国内外同类产品的水平。该仪器具有灵敏度高、检出限低、样品前处理简单等优点,实现了液体、固体样品中超痕量汞的直接测定。所采用的光纤传导技术和暗室原子化系统,可有效的减少光传输过程的损失,消除了杂散光的干扰,仪器结构紧凑；采用金汞齐富集装置,有效地消除基体干扰,提高了测定灵敏度。3.原子荧光测汞仪测定水中超痕量的汞采用研制的原子荧光测汞仪,成功地测定了西安涟漪纯净水、自来水和地表水中超痕量汞。线性范围0.005-1.000ng/mL,线性相关系数大于0.999,检出限低于0.5×10-12ng/mL,回收率在95-98%之间。结果表明,本方法是一种快速、准确、高灵敏的水中超痕量汞的测定方法。4.原子荧光测汞仪测定土壤中的汞采用设计的固体样品自动进样器,以原子荧光测汞仪进行了国家标准土壤样品中(GBW07402、GBW07423、GBW07401、GBW07404、GBW07406、GBW07411、GBW07405和GBW07302)痕量Hg的分析测定。线性相关系数大于0.998,检出限低于0.003ng,RSD小于4.0%,回收率为103%。结果表明：本方法提高了样品的分析速度,是一种快速、环保、准确的测定土壤中痕量汞的方法。5.固体进样-原子荧光光谱法同时测定砷和锑首次提出低温热释放直接进样技术,成功地设计出固体直接进样装置。与多通道原子荧光光谱仪在线连接,实现了热释放、吸收、化学蒸气发生、测定、清洗等步骤在线自动完成。固体样品直接进样,进行了土壤和岩石样品中痕量As和Sb的分析测定。以溴化铵为释放剂,实现了低温条件下元素As和Sb的溴化物定量释放,同时测定了样品中痕量As和Sb的含量。检出限分别为0.009和0.004gg/g,最小检出量分别为0.028和0.013μg/g,线性相关系数均大于0.998。6.原子荧光光谱法同时测定砷、锑、硒和汞采用多通道原子荧光光谱仪,进行了中药样品中As、Sb、Se和Hg的同时分析测定。研究优化了实验条件,包括样品预处理条件、化学蒸气发生、原子荧光的测试条件等。As、Sb、Se和Hg同时测定方法的检出限分别为0.051、0.034、0.050和0.0058ng/mL,线性相关系数均大于0.998,精密度RSD均小于1.5%。7.原子荧光光谱法同时测定铅、锡和镉首次提出双化学蒸气发生系统(即以元素Cd和部分Sn化学蒸气生成的体系为系统1,以元素铅和部分Sn化学蒸气生成的体系为系统2),以该双化学蒸气发生系统,采用多通道原子荧光光谱仪,实现了原子荧光光谱法同时测定生物样品中痕量的Pb、Sn和Cd。研究优化了元素Pb、Sn和Cd化学蒸气发生条件和测试条件。方法灵敏度高,无记忆效应,线性相关系数均大于0.996,Pb、Sn和Cd的检出限分别为0.071、0.052和0.0002ng/mL,精密度均小于3.5%。更多还原

【Abstract】 As theworld economy was rapid developed and the population grew, the attention focused today on the environment. And the heavy metal pollution was a source of environmental contamination. The research on rapid, sensitive and accurate determination of heavy metal was very important for environment.Atomic fluorescence spectrometry (AFS) is famous for its high sensitivity, low detection limit and little memory effect, which is used for determination of As, Sb, Hg and so on. Trend for the development of modern AFS, the author studied the atomic fluorescence mercury analyzer and multi-elements analysis methods. The high sensitive atomic fluorescence mercury analyzer and solid sampling device have been designed and developed, dual chemical vapor generation system and atomic fluorescence multi-elements analysis methods have been studied.The dissertation includes the following seven chapters:1. IntroductionThis chapter presented the history of the development, basic principles, equipment and structure, and the application of atomic fluorescence techniques. The author reviewed the development tendency for AFS was also presented.2Research on high sensitive atomic fluorescence mercury analyzerBy fiber optic technology, self-designed darkroom atomic device and gold amalgamation enrichment devices, the author developed the atomic fluorescence mercury analyzer. The results indicated the instrument’s main technical parameters had already reached the level of the congener domestic and foreign products, and some of technical parameters were better than them. And it has high sensitivity, low detection limit and simple sample pretreatment for direct analysis of liquid and solid samples. The author developed the fiber optic technology and the darkroom to the atomic fluorescence instrument for the first time, reduced effectively the loss of light propagation in air, descended the interference of the external light and made it compact in the design. With the application of enrichment devices, it effectively not only eliminated matrix interference, but also increased the sensitivity of determination.3. Determination of ultra trace mercury by atomic fluorescence mercury analyzer in waterBy the atomic fluorescence mercury analyzer, the author successfully determined ultra trace mercury in pure water, tap water and ground water. Linear range was0.005-1.000ng/mL, the Correlation coefficient(r) was more than0.999, detection limit is less than0.5x10-12ng/mL, and the recovery was from95%to98%. Thus, it was a rapid, accurate and high sensitive method of ultra trace mercury analysis in water.4. Direct determination of mercury in soil by atomic fluorescence mercury analyzerBy the fluorescence mercury analyzer, the author designed automatic injector for solid samples to achieve direct solid sampling, and successfully detected Hg in different soil samples (GBW07402、GBW07423、GBW07401、GBW07404、GBW07406、GBW07411、 GBW07405and GBW07302). The Correlation coefficient (r) was more than0.998, the detection limit is less than0.003ng, the relative standard deviation (R.S.D.) was less than4.0%and the recovery was103%. The method increased the speed of sample analysis and reduced the cost of determination, which was very rapid, accurate for ultra trace mercury analysis in soil.5. Solid sampling-simultaneous determination of arsenic and antimony by AFSThe author first proposed the low-temperature heat release for solid samples for AFS. The solid sampling device was designed, and connected to multi-channel atomic fluorescence spectrometer successfully. The steps were online operated that release, absorption, chemical vapor generation, determination and purge. According to volatile characteristics of the elements halide of AFS measurement, the author added NH4Br into solid samples for reducing the heat release temperature, and achieved rapid and quantitative release target elements at low temperature. The author succeeded in direct solid sampling and simultaneous determination of trace As and Sb in soil and rock. The detection limit of As and Sb was respectively0.009and0.004μg/g, the least detection concentration was respectively0.028and0.013, and the Correlation coefficient (r) was all more than0.998.6. Simultaneous determination of arsenic, antimony, selenium and mercury by AFSThe author studied and optimized experimental conditions of simultaneous determination of As, Sb, Se and Hg by multi-channel atomic fluorescence spectrometer, including sample preparation, chemical vapor generation and atomic fluorescence detection. The author achieved to determinate simultaneously As, Sb, Se and Hg in traditional Chinese medicine by AFS. The detection limit of As, Sb, Se and Hg was respectively0.051、0.034、0.050and0.0058ng/mL, the Correlation coefficient (r) was all more than0.998, and the relative standard deviation (R.S.D.) was all less than1.5%.7. Simultaneous determination of lead, tin and cadmium by AFSThe author proposed dual chemical vapor generation system for the first time for AFS (The system1included Cd and part of the Sn chemical vapor generation, and the system2 included Pb and part of the Sn chemical vapor generation). The author achieved to determinate simultaneously Pb, Sn and Cd in biological samples by dual chemical vapor generation system chemical and multi-channel atomic fluorescence spectrometer. And the experimental conditions of simultaneous determination of Pb, Sn and Cd were studied and optimized. The method had high sensitivity and little memory effect. The Correlation coefficient (r) was all more than0.996, the relative standard deviation (R.S.D.) was all less than3.5%, and detection limit of Pb, Sn and Cd was respectively0.071、0.052and0.0002ng/mL.更多还原