Simple Approach Based On Ultrasound-Assisted Emulsification Microextraction For Determination Of β-Sitosterol In Dietary Supplements And Selected Food Products

Abstract

A novel method based on ultrasound-assisted emulsification microextraction (USAEME) was proposed for the determination of β-sitosterol (β-SIT) in dietary supplements and selected food products using liquid chromatography coupled with UV. Mostly, USAEME is used for preconcentration analytes from water samples. The influences on the extraction efficiency were studied. Hexane was used as extraction solvent. Parameters such as volume of extraction solvent, temperature, ionic strength, effect of sonication were checked. Under optimum conditions, β-SIT was quantitatively extracted achieving enrichment factor (EF) equals 97. The limit of detection (LOD) and quantification (LOQ) of the β-SIT for the preconcentration of 5 mL sample volume were 0.013 µg mL−1 and 0.04 µg mL−1, respectively. The calibration curve was linear within the concentration range of 0.04–12.44 µg mL−1. The coefficient of estimation was 0.9979 ± 0.0014. The relative standard deviations were 4.65% (at n = 5, intraday) and 5.21% (at n = 15, interday). Recovery value was 99.84 ± 3.37%. The new prescribed methodology has been applied to determine this phytosterol in supplements, vegetables (broccoli, black olives, romaine lettuce, pea) and fruits (bananas, apples, mandarins, lemons). To the best of our knowledge, this is the first time that USAEME has been applied to isolate β-SIT from methanol samples obtained from real samples.