SUPERCRITICAL-FLUID EXTRACTION OF T-RESVERATROL AND OTHER PHENOLICS FROM A SPIKED SOLID

Supercritical fluid extraction of spiked phenolics including gallic ac id, (+)-catechin, (-)-epicatechin, caffeic acid, p-coumaric acid, myri cetin, t-resveratrol, quercetin and salicylic acid from an inert suppo rt using pure CO2 and methanol-carbon dioxide mixtures was studied. Ex traction and collection variables including modifier percentage, extra ction temperature, flow rate, extraction time, trap packing and rinse solvent were optimized. The study revealed that the use of methanol as modifier was mandatory. Only the less hydroxylated compounds such as p-coumaric acid, t-resveratrol and salicylic acid could be quantitativ ely recovered (mean recovery greater than or equal to 95%) from spiked diatomaceous earth. Mean recoveries of more polar phenolic acids and flavonoids such as gallic acid, caffeic acid, catechins and quercetin were between 30% and 70%. Myricetin was not recovered at all.