Characterization of supercritical fluid extracts from raw wool by TLC-FID and CC-MS

Extraction selectivity of whole wool wax from raw wool by using ethanol-modified carbon dioxide at constant pressure (100 bar) and temperature (60degreesC) was studied. A kinetic study was carried out to optimize the percentage of ethanol and the extraction time. The modified carbon dioxide was decompressed in ethanol as a collection solvent, leading to the formation of two different fractions as a function of their solubility. Qualitative and quantitative analyses of the lipid classes present in the collected fractions were performed by TLC coupled to an automated FID system (TLC-FID). Moreover, a detailed structural comparison was carried out between the aliphatic high-molecular-mass esters and the steryl ester patterns by means of subambient pressure GC-MS in both the El and the ammonia positive Cl modes. Considerable differences in the lipid composition of the two wool wax fractions collected were observed by TLC-FlD and GC-MS.