EXTRACTION OF WOOLGREASE WITH SUPERCRITICAL CARBON-DIOXIDE

Supercritical carbon dioxide was used to extract unrefined woolgrease. The resulting product had no color and little odor, resembling high-g rade commercial lanolin. The amounts of woolgrease extracted for fixed volumes of supercritical fluid solvent were measured at 60, 70 and 80 degrees C and at pressures from 200-520 bar. In this study, the high est recoveries were obtained at 80 degrees C and pressures in excess o f 380 bar. Analysis of the extracts by capillary supercritical fluid c hromatography and thin layer chromatography indicated that the composi tion of the extract changed with extraction time. The earliest fractio ns were enriched in cholesterol and contained relatively small amounts of species with higher molecular weight. The results suggest that sup ercritical fluid extraction may be used to obtain an enriched choleste rol fraction from woolgrease.