CHROMATOGRAPHY/PLASMA MASS SPECTROMETRY FOR ULTRA-TRACE ANALYSIS

充分的风险评估和随后的纠正行动将在很大程度上 测量取决于可靠性、敏感度、有效性和低水平 用于样品分析的方法的检测能力。 这些水平现在可以通过层析和等离子质谱仪实现 我们一直在开发的技术，现在正在扩展并添加新的 尺寸。对人类健康的成本加上清洁安全的环境 担忧很容易超过财政负担，并强烈要求国家- 最先进的研究，以开发准确、精确和可靠的分析 具有潜在环境适用性的技术。 这里提出的研究是一种综合的方法，以基本 对络合物分析方法的理解和发展 环境样本。这些样品必然需要两个 可超痕量的分离技术和检测方法 测量。在此期间，已经开始了扩展的协作 项目期。这个项目有四个具体的目标与一般 目标是继续开发痕量分析方法 对环境有害的化合物。A.继续研究金属 物种形成。我们现在建议用应用程序进一步研究 与环境有关的“真实”样本类型，并将涉及广泛的 与狄克逊、沃肖斯基、毕晓普和塔博尔项目的互动。 SFC、微孔LC和胶束LC与电感耦合等离子体质谱联用的新应用 检测将提供关键的物种信息。B.超临界 萃取液(SFE)和痕量水平分析(SFC)。就像现在这样 对于我们的研究来说，保护原始物种的完整性是至关重要的， 我们的目标是研究使用超临界萃取法提取痕量的 各种感兴趣的物种。我们还将研究基本阶段 超临界流体萃取混合溶剂体系的行为。C.电迁移 用于提高分离选择性的分离。我们的目标是继续和 扩大我们对包括毛细管在内的电迁移技术的研究 电泳法与电色谱联用新技术 凭借我们灵敏的等离子质谱学，让无与伦比的 分离效率高，检测下限低。电色谱 是传统液相色谱和毛细管电泳法的混合体，可提供 这两种方法的一些优点是列数显著增加 效率。D.作为元素质谱源的电喷雾。 我们在这个项目中的目标是利用对铬形态的应用 这个问题我们已经研究了好几年了。取决于 电喷雾界面条件下，质谱图可以明显不同 从那些显示广泛聚集的对象到那些显示 从其特征质量的裸露元素到高含量的形态 跟踪级别的信息--而不需要等离子体源。

Adequate risk assessment and subsequent corrective actions will in large measure depend upon the reliability, sensitivity, efficacy and low level detection capabilities of the methods utilized for sample analysis. These levels are now possible with the chromatographic and plasma MS techniques we have been developing and are now extending plus adding new dimensions. Costs to human health plus clean and safe environment concerns easily outweigh the financial burden and strongly mandate state- of -the art research to develop accurate, precise, and robust analytical techniques with potential environmental applicability. The research proposed herein is a comprehensive approach to basic understanding and development of analytical methods for complex environmental samples. These samples, by necessity, require both separation techniques and detection methods capable of ultra-trace measurement. Extended collaborations have begun during this current project period. This project has four specific aims with the general goal to continue development of trace methods of analysis for environmentally hazardous compounds. A. Continue studies of metal speciation. We now propose to do further our studies with applications to environmental relevant "real" sample types and will involve extensive interactions with the projects by Dixon, Warshawsky, Bishop and Tabor. New applications with SFC, microbore LC, and micellar LC with ICP-MS detection will provide critical speciation information. B. Supercritical fluids for extraction (SFE) and trace level analysis (SFC). As it is critical to our studies that the original species integrity be preserved, we aim to study the use of SFE for the extraction of trace levels of various species of interest. We also will study the fundamental phase behavior of mixed solvent systems for SFE. C. Electromigration separations for improved separation selectivity. We aim to continue and expand our studies of Electromigration techniques including capillary electrophoresis (CE) and a new technique, electrochromatography coupled with our sensitive plasma mass spectrometry to allow unparalleled separation efficiency and low detection limits. Electrochromatography is a hybrid of traditional liquid chromatography and CE, which offers some of the advantages of both methods with a dramatic increase in column efficiency. D. Electrospray as a source for elemental mass spectrometry. Our aims in this project are to utilize applications to the Cr speciation problem we have been studying for several years. Depending on the Electrospray interface conditions, markedly different mass spectra can be attained from those showing extensive clustering to those showing the bare element at its characteristic mass to a high amount of speciation information at trace levels - and without the need for the plasma source.