INSITU MONITORING OF EXTRACTION AND SEPARATION BEHAVIOR OF LIPIDS WITH SUPERCRITICAL CARBON-DIOXIDE

On-line supercritical fluid extraction system (SFE) with Fourier transform infrared spectroscopy (FTIR) has been developed. Effluent species can be analyzed by FTIR at the same high pressures as for the extraction. An on-line supercritical fluid chromatography system (SFC) has also been developed by modifying the SFE system with adding a separation column in the line between the extractor and the FTIR. These systems were used for the measurements of extraction yields of lipids such as higher fatty acids and DL-alpha-tocopherol and in situ observation of the separation behavior of their mixtures in supercritical carbon dioxide (SC-CO2). The extraction yield was well correlated with a parameter derived from the solubility parameter concept. The separation efficiency was represented by a model introducing several aspects of solvation power of SC-CO2 as well as interaction forces of solute with stationary (silica gel or silver nitrate coated silica gel) and mobile (SC-CO2) phases.