Reversed-phase single drop microextraction followed by high-performance liquid chromatography with fluorescence detection for the quantification of synthetic phenolic antioxidants in edible oil samples

Abstract

The reversed-phase mode of single drop microextraction has been used as a preparation method for the extraction of some phenolic antioxidants from edible oil samples. Butylated hydroxyl anisole, tert-butylhydroquinone and butylated hydroxytoluene were employed as target compounds for this study. High-performance liquid chromatography followed by fluorescence detection was applied for final determination of target compounds. The most interesting feature of this study is the application of a disposable insulin syringe with some modification for microextraction procedure that efficiently improved the volume and stability of the solvent microdrop. Different parameters such as the type and volume of solvent, sample stirring rate, extraction temperature, and time were investigated and optimized. Analytical performances of the method were evaluated under optimized conditions. Under the optimal conditions, relative standard deviations were between 4.4 and 10.2%. Linear dynamic ranges were 20-10 000 to 2-1000 μg/g (depending on the analytes). Detection limits were 5-670 ng/g. Finally, the proposed method was successfully used for quantification of the antioxidants in some edible oil samples prepared from market. Relative recoveries were achieved from 88 to 111%. The proposed method had a simplicity of operation, low cost, and successful application for real samples.

Current sample preparation methods and analytical techniques for the determination of synthetic antioxidants in edible oils

“…With the increasing awareness of health, the analysis of synthetic antioxidants in edible oils has attracted more and more attention, and various analytical methods have been developed. Considering the relatively low concentration of synthetic antioxidants and the complex matrix in various edible oils, establishing an efficient sample preparation method to eliminate the irrelevant interferents is vital for the subsequent detection [10]. Selection of the appropriate analytical techniques for detection is also critical for successful quantify of the content of synthetic oxidants in edible oils.…”

“…FLD offers higher sensitivity and lower detection limit in comparison with the UV detector [16]. Farajmand et al established a method based on SDME coupled with HPLC-FID for quantifying BHA, BHT, and TBHQ in the blended oil samples [45]. They choose 270 nm and 350 nm as the excitation and emission wavelength, respectively.…”

“…, Farajmand et al successfully used reversed-phase SDME (RP-SDME) followed by RP-HPLC to determine the content of BHA, BHT, and TBHQ in blended oil[10]. In detail, polar solvent (ACN/EtOH) mixture was transferred into the modified insulin syringe, which was then immersed in the stirring oil sample atF I G U R E 3 (A) General setup of reversed-phase SDME (RP-SDME).…”

Simultaneous determination of furfural and its degradation products, furoic acid and maleic acid, in transformer oil by the reversed‐phase vortex‐assisted liquid–liquid microextraction followed by high‐performance liquid chromatography

“…Farajmand et al. measured the synthetic phenolic antioxidants in edible oil samples oil by RP single‐drop microextraction (RP‐SDME) and HPLC with fluorescence detection using acetonitrile/ethyl alcohol (50:50, v/v) mixture as extractant. Mercedes et al.…”

“…LLME has been widely applied to the pretreatment of organic matter in water, however it is rarely used for tracing organic matter in oil matrix. Farajmand et al [15] measured the synthetic phenolic antioxidants in edible oil samples oil by RP single-drop microextraction (RP-SDME) and HPLC with fluorescence detection using acetonitrile/ethyl alcohol (50:50, v/v) mixture as extractant. Mercedes et al [16] measured the phenolic compounds in olive oil by LLME-UHPLC-MS using methanol/water (4:1, v/v) mixture as extractant.…”