In–syringe homogenous liquid–liquid extraction combined with ionic liquid based dispersive liquid–liquid microextraction for the extraction of aflatoxin B1 from edible vegetable oil samples prior to HPLC-FLD analysis

Abstract

Combination of in–syringe homogenous liquid–liquid extraction and ionic liquid based dispersive liquid–liquid microextraction has been employed for the extraction of aflatoxin B1 from edible vegetable oil samples. Firstly, a homogenous solution of oil sample containing the analyte and acetone (1.5 mL) is formed. Then, this homogenous state was broken by adding 100 µL of deionized water and the analyte was extracted into the produced fine droplets of acetone. In the following, acetone phase was taken and mixed with 65 µL of 1–hexyl–3–methylimidazolium tetrachloroferrate magnetic ionic liquid. The mixture was injected to sodium chloride solution (5 %, w/v) by a glass syringe. The ionic liquid droplets were collected by an external magnet and then, they were used for the determination step by high–performance liquid chromatography equipped with fluorescence detector. Under the optimum conditions, low limit of detection (13 ng kg−1) and quantification (44 ng kg−1), wide linear range (44–1 × 106 ng kg−1), acceptable extraction recovery (69 %), and good precision (relative standard deviations ≤ 4.0 %) were obtainable using the proposed method. These results verify the high capability of the proposed method for screening aflatoxin B1 in the various edible vegetable oil samples. Performing the method in syringe barrel provide easy collection of the extraction solvent without the need for centrifugation. Combination of homogenous liquid–liquid extraction with the microextraction procedure leads to obtain sensitive detection limits. The use of ionic liquid removed the necessity of centrifugation for separation of the extractant.