title: Development of coupled ultrasound-assisted and reversed-phase dispersive liquid-liquid microextraction before high-performance liquid chromatography for the sensitive determination of vitamin A and vitamin E in oil samples.
abstract: A new approach based on the ultrasound-assisted reversed-phase dispersive liquid-liquid microextraction technique is developed for the extraction and determination of vitamin A and vitamin E from oil matrices before high-performance liquid chromatography analysis. A methodology based on the full factorial design is carried out to choose the significant parameters. Then the significant factors affecting the extraction efficiency including pH, volume of extraction solvent, and volume of disperser solvent are optimized using a Box-Behnken design. After analyzing the results obtained, the optimum conditions were: pH 4.5, 80-20 μL of the ethanol/water solvent mixture as extraction solvent, 110 μL of 1,4-dioxane as the disperser solvent, and a sonication time of 10 min. For validation of the developed method, the linear dynamic range, repeatability, limit of detection, and recoveries were obtained under the optimum conditions. The detection limits of the method were 1.6 and 2.3 ng/mL for vitamin A and vitamin E, respectively. The extraction recovery percentages for the studied drugs were above 91%, with acceptable relative standard deviation. The proposed methodology was successfully applied for the determination of the vitamins in different oil samples.
authors.affiliation: Faculty of chemistry, University of Shahrood, Shahrood, Iran.
authors.forename: Nasser
authors.initials: N
authors.lastname: Goudarzi
authors.affiliation: Faculty of chemistry, University of Shahrood, Shahrood, Iran.
authors.forename: Sahar
authors.initials: S
authors.lastname: Farsimadan
authors.affiliation: Faculty of chemistry, University of Shahrood, Shahrood, Iran.
authors.forename: Mansour
authors.initials: M
authors.lastname: Arab Chamjangali
authors.affiliation: Faculty of chemistry, University of Shahrood, Shahrood, Iran.
authors.forename: Ghadam Ali
authors.initials: GA
authors.lastname: Bagherian
keywords: Box-Behnken design; Microextraction; Olive oil; Vitamin A; Vitamin E