Natural deep eutectic solvent as an efficient extractant for fast and ligandless vortex-assisted dispersive liquid–liquid microextraction of thallium

Abstract

A hydrophobic natural deep eutectic solvent (NADES) composed of lauric acid, thymol, and camphor at a molar ratio of 1:3:1 was utilized for the first time as an extractant for the dispersive liquid–liquid microextraction of Tl(I) in water samples. Excellent extraction efficiency was achieved by adding 500 µL of NADES into a water sample of pH 11–12, followed by vortex mixing for 30 s at 500 rpm to avoid the use of any dispersing and chelating agents. The concentration of Tl(I) in the NADES phase was measured by flame atomic absorption spectrometry (FAAS) after ethanolic dilution. The limits of detection and quantification were found to be 9 μg L⁻¹ and 31 μg L⁻¹, respectively. The applicability of the proposed method was confirmed by the analytical recoveries (97–106 %) obtained from the analysis of spiked samples of tap, bottled, and surface waters, while reproducibility, expressed as RSD, was below 9 %. The Blue Applicability Grade Index (BAGI) and Click Analytical Chemistry Index (CACI) were used to evaluate the practical utility of the method. The greenness assessment using the AGREE, AGREEprep and MoGAPI metric tools showed that the method complies with the principles of Green Analytical Chemistry.