Determination of selenium in cereal and biofortified samples by ICP-OES using an alcohol-based deep eutectic solvent in digestion procedure

The application of deep eutectic solvents (DESs) as green solvents in analytical chemistry has attracted increasing attention. The present study presents a simple, eco-friendly, and cost-effective approach for the extraction of selenium (Se) in food samples. The extraction method utilised alcohol-based DES and inductively coupled plasma optical emission spectrometry (ICP-OES) to determine total Se. Factors affecting the extraction procedure were optimised using the design of experiments. Using the optimal conditions, the limits of detection (LOD) and quantification (LOQ) and linearity of the developed method were 0.0011 µg Se/g, 0.0037 µg Se/g and 0.004–0.20 µg Se/g, respectively. The precision expressed as relative standard deviations (RSDs) was less than 10 %. The accuracy of the method was investigated using certified reference materials (IRMM 804 Rice Flour and NIST SRM 1567b wheat flour), and the results were in close agreement with the certified values (0.038 µg/g and 1.14 µg/g) with percentage recoveries ranging from 89.5 to 106 %. The interday ( %RSD) and Intraday ( %RSD) were 2.8–5.4 % and 4.3–5.9 %, respectively. The greenness of the method was assessed using NEMI, AES, and AGREE metrics tools. When comparing all these tools, they all qualified the proposed method as green.