|Turner, Charlotta - USDA-ARS-WRRC|
|King, Jerry - LOS ALAMOS NATIONAL LAB|
Submitted to: Journal of Association of Official Analytical Chemists International
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 21, 2003
Publication Date: July 1, 2004
Citation: Turner, C., King, J.W., Mckeon, T.A. 2004. Selected uses of enzymes with critical fluids in analytical chemistry. Journal of Association of Official Analytical Chemists International.2004. 87: 797-810 Interpretive Summary: This manuscript critically reviews the literature on enzyme reactions in supercritical carbon dioxide, which has the solubilizing properties of an organic solvent, the diffusion properties of a gas and is environmentally safe. The applications are especially useful for vegetable oil extraction and conversion, and include analysis, synthesis and processing. We have developed methods using this technology and applied these methods for analysis of oil from castor seed. The coupling of supercritical carbon dioxide as a medium for enzyme reactions represents a safe alternative to traditional chemical conversion and solvent extraction processes.
Technical Abstract: Abstract The use of enzymes coupled with supercritical fluid-based analytical techniques, such as supercritical fluid extraction (SFE), provides a safer environment platform for the analytical chemist and reduces the use of organic solvents. Incorporation of such techniques not only reduces the use of solvent in analytical laboratories, but can lead to overall method simplification and time savings. In this review some of the fundamental aspects of using enzymes in the presence of supercritical fluid media are discussed, particularly the influence of extraction (reaction) pressure, temperature, and water content of the extracting fluid and/or sample matrix. Screening of optimal conditions for conducting reactions in the presence of SF media (SFR) can be readily accomplished on automated serial or parallel SFE instrumentation, including selection of the proper enzyme. Numerous examples are cited, many based on lipase-initiated conversions of lipid substrates, to form analytical useful derivatives for GC, HPLC, or SFC analysis. In certain cases, enzymatic-aided processing of samples can permit the coupling of the extraction, sample preparation, and final analysis steps. The derived methods/techniques find application in nutritional food analysis, assaying of industrial products, and the micro- analysis of specific samples.