title: Reverse micelle formation for acceleration of the supercritical fluid extraction of cholesterol from food samples.
abstract: Reverse micelle formation is presented as a new strategy for improving the extraction of polar species with supercritical (SC) CO2. The addition of a reverse-micelleforming reagent prior to SFE accelerates the quantitative extraction of the analyte. The effect was used to develop a method for the determination of cholesterol in solid foods. The proposed method involves the addition of a microemulsion of a nonionic surfactant (Triton X-100) to the sample and dynamic extraction with SC-CO2 at 383 bar and 40 degrees C for 20-40 min. The method was validated using a certified reference material (NIST-SRM 1845) and was subsequently used to analyze low-cholesterol (whole bread, oat biscuits, orange biscuits) and high-cholesterol foods (semiskimmed and whole milk) with excellent results (RSD < 11% in all instances).
authors.affiliation: Department of Analytical Chemistry, Faculty of Sciences, University of Córdoba, Spain.
authors.forename: M M
authors.initials: MM
authors.lastname: Jiménez-Carmona
authors.forename: M D
authors.initials: MD
authors.lastname: Luque de Castro
mesh_terms: D000818:Animals; D001939:Bread / Q000032:analysis; D002245:Carbon Dioxide / Q000737:chemistry*; D002784:Cholesterol / Q000032:analysis* / Q000302:isolation & purification*; D004655:Emulsions; D005504:Food Analysis; D008823:Micelles; D008892:Milk / Q000737:chemistry; D017830:Octoxynol / Q000737:chemistry*; D011312:Pressure; D012015:Reference Standards; D015203:Reproducibility of Results
chemical_list: D004655:Emulsions; D008823:Micelles; D002245:Carbon Dioxide; D017830:Octoxynol; D002784:Cholesterol