Extraction and preconcentration of Aflatoxin M1 based on deep eutectic solvents from cheese samples

Abstract

Introduction: Mycotoxins are one of the natural compounds produced by fungies. Aflatoxins are the most important group of mycotoxins. Among the aflatoxins, aflatoxin B1 and its hydroxylated metabolite including AFM1 is more important other ones. Expression of purpose: The main goal of this study was the development of a ternary phase extraction system combined with deep eutectic solvent-based dispersive liquid–liquid microextraction for the extraction of aflatoxin M1 from cheese samples prior to its determination by HPLC-FLD. Method: For this purpose, 1 g of cheese sample was transferred into a glass test tube and then 2 mL of deionized water, 2.1 mL of acetonitrile, and 1 mL of n-hexane were added on the sample with an appropriate amount of sodium chloride. The obtained mixture was vortexed and then centrifuged. Then, the middle phase (acetonitrile) was removed and mixed with 64 µL of DEAC-carvacrol DES and the obtained mixture was dispersed into 5 mL deionized water with a glass syringe. The obtained cloudy solution was centrifuged and the sedimented phase was analyzed by the determination system. Results: Under optimal conditions, limits of detection and quantification were 0.74 and 2.5 ng kg–1, respectively. The obtained extraction recovery and enrichment factor were 94% and 94, respectively. Also, intra– (n=6) and inter–day (n=4) precisions were equal to 5.3% and 8.6% at a concentration of 5 ng kg-1, respectively. Discussion and conclusion: According to the results, this method can be used as an applicable method for extraction, preconcentration, and determination of AFM1 in cheese samples. Several cheese samples were analyzed and AFMs was found on them in the range of 48.2-196 ng/kg.