APPLICATION OF SUPERCRITICAL FLUID EXTRACTION AND CHROMATOGRAPHY TO THE ANALYSIS OF TURMERIC

Supercritical fluid extraction (SFE) and supercritical fluid chromatography (SFC) have been applied to the analysis of turmeric, the rhizomes of the plant Curcuma longa L. Using modified carbon dioxide as the extractant, SFE resulted in the removal of turmerones and other volatile compounds from the sample. Methanol-modified carbon dioxide enabled the extraction of the curcuminoids, and under optimized conditions gave more than 90% recovery of curcumin, the major component. This technique allowed easy separation of the solvent from the extracts. On-line coupling of SFE with SFC using pressure reduction to focus the sample onto the top of the column was carried out for the analysis of turmeric. Fractionation of turmerones and curcuminoids was possible in a single run, and the separation of curcuminoids by SFC was comparable to that done by high performance liquid chromatography (HPLC). This method can potentially be used for the analysis of compounds with highly volatile or aromatic components that are difficult to extract and/or trap. © Oxford University Press 1993.