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 i n 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.
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