Type of Document Master's Thesis Author Brannegan, Daniel Robert URN etd-03302000-20440044 Title Analysis of Ethoxyquin and its Oxidation Products using Supercritical Fluid Extraction and High Performance Liquid Chromatography with Chemiluminescent Nitrogen Detection Degree Master of Science Department Chemistry Advisory Committee
Advisor Name Title Taylor, Larry T. Committee Chair Glanville, James O. Committee Member McNair, Harold M. Committee Member Keywords
- Beef Fat
Date of Defense 2000-03-10 Availability unrestricted AbstractEthoxyquin is an antioxidant commonly used to preserve vitamins and lipids in various food products and animal feeds. The extraction and determination of ethoxyquin is becoming increasingly important as products, which are labeled as "natural" are becoming more common. The present method of determination only ensures that ethoxyquin values are below 10-20 parts per million. Therefore, advances are needed in methods of extraction and analysis in order to lower the detection limits in various products.
The first part of this research investigates the use of supercritical fluids in the extraction of ethoxyquin from lean beef and beef fat. Supercritical fluids offer the advantages of safety, time, expense, and selectivity over liquid extractions. Three fluids were examined: carbon dioxide, trifluoromethane, and 1,1,1,2-tetrafluoroethane. Carbon dioxide appeared to react with ethoxyquin during the extraction. Methanol modified hydrofluorocarbons provided more complete extractions over pure hydrofluorocarbon fluids. Methanol modified 1,1,1,2-tetrafluoroethane was used in the extraction of ethoxyquin from lean beef and beef fat, and provided a quantitative extraction at the 0.5 ppm level.
The second part of this research centered on the separation and quantitation of the oxidation products of ethoxyquin through the use of high pressure liquid chromatography with chemiluminescence nitrogen detection (HPLC/CLND). When ethoxyquin is oxidized, the resulting products also exhibit antioxidative properties. While these oxidation products are known, no effort has been made to separate and quantify them in real or clean samples. HPLC/CLND allows all nitrogen containing compounds to be quantified without a known standard. This method is of extreme interest in the case of ethoxyquin oxidation products, or other types of metabolites, where standards are difficult to obtain or are unstable. HPLC/CLND allowed a separation of ethoxyquin and four of its oxidation products to be detected, thus making future studies of the antioxidant behavior of ethoxyquin feasible.
Filename Size Approximate Download Time (Hours:Minutes:Seconds)
28.8 Modem 56K Modem ISDN (64 Kb) ISDN (128 Kb) Higher-speed Access Theses316_doc.pdf 790.94 Kb 00:03:39 00:01:52 00:01:38 00:00:49 00:00:04
If you have questions or technical problems, please Contact DLA.