Deep eutectic solvent based ultrasound assisted emulsification microextraction for preconcentration and voltammetric...

A new and simple deep eutectic solvent based ultrasound-assisted emulsification microextraction (DES-UAEME) procedure has been developed for preconcentration and voltammetric determination of aflatoxin B1 (AFB1) in cereal products. The method is based on the acetonitrile-based extraction of AFB1 from homogenized cereal samples followed by a DES-UAEME procedure for subsequent differential pulse voltammetry (DPV) determination in a microcell. A DES composed of choline chloride and urea (ChCl-Ur) was used as the extraction solvent and electrolyte for DPV detection. Various parameters affecting the extraction efficiency of AFB1 were evaluated and optimized. Under optimum conditions the calibration graph was linear in the range of 0.2-80.0 μg L^-1 (R² = 0.9966) and the limit of detection (3S_b) was estimated to be 0.05 μg L^-1. The intra-day and inter-day precision (RSD%) for determination of 5.0 μg L^-1 AFB1 were 3.4% and 3.9%, respectively. The proposed method was also successfully applied for preconcentration and determination of AFB1 in different cereal samples and good relative recoveries were obtained over a range of 94 to 104%.