title: Supercritical fluid extraction of phenol compounds from olive leaves.
abstract: A clean, highly selective supercritical fluid extraction (SFE) method for the isolation of phenols from olive leaf samples was examined. Total phenol extracts were determined using the Folin-Ciocalteu reagent. Dried, ground, sieved olive leaf samples (30 mg) are subjected to SFE, using carbon dioxide modified with 10% methanol at 334 bar, 100 degrees C (CO(2) density 0.70 g ml(-1)) at a liquid flow-rate of 2 ml min(-1) for 140 min. Diatomaceous earth is used to reduce the void volume of the extraction vessel. The influence of extraction variables such as modifier content, pressure, temperature, flow-rate, extraction time, and collection/elution variables, were studied. Supercritical fluid extracts were screened for acid compounds such as carboxylic acids and phenols using Electrospray-MS (in the negative ionization mode). SFE was found to produce higher phenol recoveries than sonication in liquid solvents such as n-hexane, diethyl ether and ethyl acetate. However, the extraction yield obtained was only 45%, using liquid methanol.
authors.affiliation: Department of Analytical Chemistry, Faculty of Sciences. University of Córdoba, E-14004 Córdoba, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Le Floch
authors.forename: M T
authors.initials: MT
authors.lastname: Tena
authors.forename: A
authors.initials: A
authors.lastname: Ríos
authors.forename: M
authors.initials: M
authors.lastname: Valcárcel