Green synergy: a novel deep eutectic solvent in eco-friendly air-assisted solidified floating drop microextraction for ultrasensitive lead determination

Abstract

A novel and green analytical technique was developed to determine lead in water, wastewater, and food samples. A new hydrophobic deep eutectic solvent (HDES) contains 2,2′-(1H-benzo[d]imidazole-1,2-diyl) diphenol (BIP) and 1-dodecanol. This HDES was used as a synergistic solvent for air-assisted solidified floating organic drop microextraction (AA-SFODME). After extraction and preconcentration, lead was quantified using graphite furnace atomic absorption spectrometry (GFAAS). The method demonstrated excellent analytical performance, with a wide linear range of 0.05–950 µg L⁻¹ and an enhancement factor (EF) of 50.0. The limits of detection (LOD) and quantification (LOQ) were 0.02 µg L⁻¹ and 0.06 µg L⁻¹, respectively. The accuracy of this method was confirmed by analyzing certified reference materials (CRMs). Furthermore, the applicability and sustainability of the procedure were evaluated and compared. The Blue Applicability Grade Index (BAGI), the Sample Preparation Metric of Sustainability (SPMS), and the Environmental, Performance, and Practicality Indicator (EPPI) tool scores were 75.0, 8.84, and 81.5, respectively. The results show significant improvement in environmental friendliness compared to previously reported methods for similar sample types.