An Eco‐Friendly Approach for Determination of Lead in Biological Samples after Deep Eutectic Solvent Extraction

Abstract

The present research proposes investigating deep eutectic solvents for extracting Pb from biological samples for further determination by GF AAS. Among the synthesized solvents, the DES obtained from choline chloride and oxalic acid (ChCl : Ox) in a molar ratio 1 : 1 presented the best lead (Pb) extraction efficiency. Subsequently, it was characterized by Fourier Transform Infrared Spectroscopy (FTIR). For extraction, the optimized conditions were: 40 mg of sample, 400 μL of DES (ChCl : Ox) added, and 30 min at 95±5 °C. The supernatant was diluted, and the Pb was determined by GF AAS. The optimized instrumental conditions for Pb determination were 900 °C and 2100 °C, pyrolysis and atomization temperatures, respectively, using Pd as a chemical modifier. The limits of detection and quantification were 0.04 and 0.12 μg g−1, respectively. The method's accuracy was evaluated by analyzing the certificate reference materials, and good agreement was obtained between the determined and certificate values. The greenness of the proposed method was evaluated by green star and eco‐scale metrics. Thus, the proposed method proved simple, efficient, and eco‐friendly for determining Pb in biological samples.