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Douglas Raynie, Research Associate Professor
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Phone: (605) 688-4549
Fax: Fax: (605) 688-6364
E mail: E mail Dr. Douglas Raynie
Education
B.A., 1981, Augustana College
M.S., 1983, South Dakota State University
Ph.D., 1990, Brigham Young University
External Funding
FDA, USDA
Research Interests
analytical separations, supercritical fluid chemistry
Topics
sample preparation strategies for bio-based materials; bio-processing in supercritical fluids
Research Description
At elevated temperatures and pressures (i.e., above the critical point) compounds become supercritical fluids and possess properties intermediate between gases and liquids. These fluids dissolve solutes, yet have gas-like diffusivity and surface tension. Importantly, these properties can be varied as a function of temperature and pressure. Resulting chemical processes in supercritical fluids can have advantages of being faster and more selective, with minimal use of hazardous organic solvents. Our research involves two related application areas of supercritical fluids.
Analytical Separations. Virtually all laboratory samples require some type of separation prior to analysis. We are interested in analytical sample preparation (i.e., extraction) and high resolution chromatography methods. In the extraction area, we use supercritical fluid extraction (SFE) and a related technique, accelerated solvent extraction, for the isolation of selected organic compounds from a variety of sample types. Areas of active interest include fundamental studies of the extraction of solid samples, the isolation of additives (antimicrobials and growth hormone) from animal feeds and tissues, and the determination of chemical contaminants that may migrate into foods during cooking. Our interests in high-resolution chromatography are in the use of supercritical fluid chromatography and high-temperature liquid chromatography for the characterization of complex samples.
Bioprocessing and Related Processes. Distillers dried grain with solubles (DDGS) is the residual matter from the ethanol fermentation of corn. We have used large-scale SFE to isolate the lipophilic portion of DDGS for characterization. DDGS is also used for the fermentation of an important biodegradable polymer, polyhydroxyalkanotes, and we are using SFE to isolate the polymer from the fermentation broth. We are using other supercritical fluid processes to hydrolyze the cellulose from biomass to important chemicals (e.g., simple sugars), to impart properties of interest (e.g., density reduction) to polymers, leather, and other products.
Publications
D. E. Raynie, "Modern Extraction Techniques," Anal. Chem. 76, 4659-4664 (2004).
D. E. Raynie, "A Fundamental Understanding of the Chemical Extraction Process," Encyclopedia of Separation Science, I. D. Wilson, T. R. Adlard, C. F. Poole, and M. Cooke (eds.), Academic Press (2000).
D. E. Raynie, "Meeting the Natural Products Challenge with Supercritical Fluids," ACS Symp. Ser. 670, 68-75 (1997).
S. H. Page, D. E. Raynie, S. R. Goates, M. L. Lee, D. J. Dixon, and K. P. Johnston, "Predictability and Effect of Phase Behavior of CO2/Propylene Carbonate in Supercritical Fluid Chromatography," J. Microcol. Sep. 3, 355-369 (1991).
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