Elemental, Micro, Ultra Trace Analysis

元素、微量、超痕量分析

• 批准号: 0315336
• 负责人: James Holcombe
• 金额: $ 55.5万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-15 至 2007-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0315336&HistoricalAwards=false
• 关键词: Elemental; Micro; Ultra; Trace; Analysis

Professor James Holcombe of the University of Texas Austin is supported by the Analytical and Surface Chemistry Program for research on microanalytical trace elemental analysis. Specifically, two areas are addressed: electrothermal vaporization (ETV) sample introduction into an inductively coupled mass spectrometer (ICPMS) and cold atom atomic absorption solution spectrometry (CAAASS). The idea is to develop analytical methods where the complexity of the matrix will not interfere with the analysis. ETV-ICPMS employs microsamples and places no sample introduction restrictions on the matrix, i.e., samples with high levels of dissolved salts, slurries and solids can all be used without dilution or digestion. Sample throughput rates, transport efficiencies and plasma loading (because of the complex matrix) are problems that are addressed. A low power, graphite-based filament system is being developed in lieu of the classical tube design or metal filament vaporizer. Insuring reproducible transport efficiency of the aerosol from the ETV to the ICP is the motivation behind the use of a microporous graphite tube and methodologies to center the aerosol in the gas flowing to the ICP. The thermal ramp of the ETV provides a crude chromatographic (thermal) separation device to inexpensively assist in discerning and circumventing interferences as well as optimizing the instantaneous signal to noise ratio. Although the proof-of-concept for ETV-ICP time-of-flight mass spectrometry has been demonstrated, this work focuses on the full implications and limitations of the method. Fundamental studies of aerosol dispersion as well as use of mixed gas plasma are also proposed. CAAASS is a novel means of generating atoms at room temperature in solution that was first demonstrated in Sturgeon's laboratory as a tool for sample introduction into an ICP. Holcombe's laboratory will investigate the fundamentals of these very interesting phenomena with the application goal of using the approach for elemental analysis via diode laser atomic absorption in a microchip. Elemental analysis remains a cornerstone in modern research and development. In the biological world, its use range from basic determination of cofactor concentrations to pharmokinetic evaluations of drugs (e.g. platinum in anticarcinogens). Because of their toxicity, many metals remain the focus of bioaccumulations. Water, soil and air analysis remains active since these are often the recirculating source of pollution and show impacts at exceedingly low levels. Basic geological sciences also rely on metals as tracers. While many viable approaches exist for basic ultratrace elemental detection, techniques for dealing with microsamples contained within a complex matrix consumes thousands of hours of effort to design methods, many of which are unique and useful only for the particular application. This research attempts to provide the broader research community with a tool that will most cost-effectively permit research to advance in a number of scientific and medical areas.

德克萨斯大学奥斯汀分校的James Holcombe教授得到了分析和表面化学项目的支持，研究微量元素分析。 具体而言，两个领域的地址：蒸发（ETV）样品引入电感耦合质谱仪（ICPMS）和冷原子吸收溶液光谱法（CAAASS）。 我们的想法是开发分析方法，其中矩阵的复杂性不会干扰分析。 ETV-ICPMS采用微量样品，对基质没有样品引入限制，即，含有高含量溶解盐、浆液和固体的样品都可以在不稀释或消化的情况下使用。 样品通过率、运输效率和血浆装载（由于复杂的基质）是要解决的问题。 正在开发一种低功率、石墨基灯丝系统，以代替经典的管设计或金属灯丝蒸发器。 确保气溶胶从ETV到ICP的可再现传输效率是使用微孔石墨管和方法将气溶胶集中在流向ICP的气体中的动机。 ETV的热斜坡提供了一种粗色谱（热）分离装置，以廉价地帮助识别和规避干扰以及优化瞬时信噪比。 虽然已经证明了ETV-ICP飞行时间质谱的概念验证，但这项工作侧重于该方法的全部含义和局限性。 气溶胶分散的基础研究以及混合气体等离子体的使用也提出了建议。 CAAASS是一种在室温下在溶液中产生原子的新方法，它首先在Sturgeon的实验室中被证明是将样品引入ICP的工具。 Holcombe的实验室将研究这些非常有趣的现象的基本原理，其应用目标是通过微芯片中的二极管激光原子吸收进行元素分析。元素分析仍然是现代研究和开发的基石。 在生物学领域，它的应用范围从辅助因子浓度的基本测定到药物的药代动力学评价（例如抗癌药中的铂）。 由于其毒性，许多金属仍然是生物累积的重点。 对水、土壤和空气的分析仍然很活跃，因为这些往往是再循环的污染源，而且影响程度极低。 基础地质科学也依赖金属作为示踪剂。 虽然存在许多可行的方法用于基本的超痕量元素检测，但用于处理复杂基质中包含的微量样品的技术消耗数千小时的努力来设计方法，其中许多方法是独特的并且仅对特定应用有用。 这项研究试图为更广泛的研究界提供一种工具，以最具成本效益的方式使研究在一些科学和医学领域取得进展。