Improvement of Sentivity and Speed of the Determination of Trace Elements by High Power Microwave Induced Plasma Atomic Emission Spectrometry

为了建立高功率微波诱导等离子体(MIP)-原子发射光谱分析(AES)新系统，提高微波诱导等离子体(MIP-AES)测定痕量元素的灵敏度和速度，在过去的三年中开展了这项工作。主要研究成果如下：1.针对目前市场上尚无高功率MIP-AES仪器的情况，设计并构建了一套新型的高功率MIP-AES系统。它由新型谐振腔和计算机控制的多元素测定光谱仪系统组成。为了提高响应时间，将计算系统中的电子电路更换为快速工作的电路。2.与普通的低功耗MIP相比，这种高功率氮气N/HP对样品溶液的连续雾化具有很大的容忍度。此外，构建的系统已经被修改为将该分子印迹聚合物与氢化物发生技术相结合作为高效的样品引入。3.随着这种新的…的使用将MIP-AES系统与传统的溶液雾化相结合，测量了背景发射光谱。结果表明，在200-400 nm的光谱范围内观察到了一些典型的分子带发射。此外，还考察了该高功率氮分子印迹聚合物在多个元素的多条发射线上的分析特性。4.为了灵敏地测定砷、锑和硒，将它们与四氢硼酸钠反应生成的气态氢化物顺利地连续输送到分子印迹聚合物中。该方法用于铜、钢中砷、锑、硒的测定，结果满意。在此基础上，建立了多元素同时测定系统，并将其应用于钢的分析中，取得了良好的效果。5.展望本项目的发展前景，新研制的高功率氮气MIP-AES系统应得到更多的检验，并应用于更广泛的实际样品中。如果这一系统能与其他分析技术相结合，化学形态形成可能成为可能，并在环境化学中发挥作用。此外，通过采用超声波雾化、电热蒸发、浆料进样、激光烧蚀、火花&电弧取样和辉光放电等进样方法，可以在很大程度上推广这一技术。较少

This project has been performed over the last three years to establish a new system of high-power micro-wave-induced plasma (MIP)-atomic emission spectrometry (AES) and to improve the sensitivity and speed of MIP-AES determination of trace elements. The results are as follows.1.In this work, a new system of high-power MIP-AES has been designed and constructed as such an instrument is not available in the marketplace. It consists of a new type of resonant cavity and a computer-controlled spectrometer system for the multi-element determination. For the improvement of response time, the electronic circuit in the computing system was replaced with a rapidly working one.2.In contrast with a common low-power MIP, this high-power nitrogen N/HP can have a great tolerance to continuous nebulization of sample solutions. Furthermore, the constructed system has been modified to combine this MIP with a hydride generation technique as a highly efficient sample introduction.3.With the use of this new … More ly constructed MIP-AES system coupled with a conventional solution nebulization, background emission spectra have been measured. As a result, some typical molecular band emissions were observed in the spectral range of 200-400 nm. In addition, analytical characteristics of this high-power nitrogen MIP were examined at many emission lines of a number of elements.4.For the sensitive determination of arsenic, antimony and selenium, their gaseous hydrides generated by the reaction with sodium tetrahydroborate were continuously conveyed into the MIP with no trouble. The hyphenated method has been successfully applied to the determination of arsenic, antimony or selenium in copper metals and steels with satisfactory results. Furthermore, the simultaneous multi-element determination system was developed and it application to steel analysis has been very successful.5.For a future prospect of this project, a newly developed high-power nitrogen MIP-AES system should be more and more examined and applied to the much wider range of practical samples. If this system can be coupled with other analytical techniques, chemical speciation might be possible and useful, for example, in environmental chemistry. In addition, this technique can be extended to a great extent by the use of a number of sample introduction methods, i.e., ultrasonic nebulization, electrothermal vaporization, slurry sample introduction, laser ablation, spark & arc sampling and glow discharge. Less