ABSTRACT 4‐Methylimidazole, a potentially toxic by‐product formed during caramel color production, has raised public health concerns due to its occurrence in beverages. In this study, a simple and efficient analytical method was developed for the trace determination of 4‐methylimidazole in energy drinks using salt‐saturated single‐drop microextraction coupled with gas chromatography–flame ionization detection. The extraction was performed by saturating the aqueous sample with NaCl, Mg(NO 3 ) 2 , and KNO 3 , followed by immersion of a 0.4 µL microdrop of 1‐indanol into the sample solution. This strategy modifies solvent–water phase behavior under salt‐saturated conditions, enabling the use of a polar microdrop in direct‐immersion single‐drop microextraction and extending the applicability of the technique to highly water‐soluble analytes. Key parameters affecting the extraction efficiency, including extraction solvent type and volume, sample volume, stirring speed, extraction time, temperature, and pH, were systematically investigated using a one‐variable‐at‐a‐time approach and optimized by response surface methodology. Under the optimized conditions, the method exhibited linearity over the concentration range of 0.01–80 mg/L, with a detection limit of 1.72 µg/L. An enrichment factor of 83 was achieved, and the total extraction time for each sample was less than 10 min. The reproducibility of the method, expressed as relative standard deviation, was better than 6.1%. The applicability of the proposed method was successfully demonstrated by satisfactory recoveries of 4‐methylimidazole in energy drink samples.
Porki et al. (Sat,) studied this question.