Magnetic deep eutectic solvent-carbon nanofiber hybrid for efficient D-μ-SPE and sensitive determination of selenium in fruit juice and drinking water with atomic fluorescence detection.

An environmentally friendly method was developed for Se determination in fruit juice and drinking water based on dispersive micro-solid phase extraction (D-μ-SPE) using a nanohybrid sorbent composed of a magnetic deep eutectic solvent (MDES) and carbon nanofibers (CNFs). The MDES, formed by decanoic acid, lauric acid and dysprosium chloride (1: 1:0.1), was combined with CNFs for efficient retention of Se and magnetic recovery of the dispersed sorption material. Different parameters, including pH, chelating agent concentration, ionic strength, MDES composition, sample volume, and hybrid amount, were optimized. Limit of detection of 0.017 μg L-1, extraction efficiency of 98.5%, and RSD of 1.16% were obtained. Successful application of the method was demonstrated through the analysis of commercial fruit juices of varied matrix composition and water samples (recovery values in the 95-105% range). The proposed method is a simple, efficient, and environmental-friendly alternative (AGREEprep score of 0.53) for Se determination in complex matrices.