Determination of Cd in some food and water samples using emulsion liquid-liquid microextraction process with hydrophobic deep eutectic solvent

Abstract

Here, a deep eutectic solvent depending on hydrophobic tetra-n-butylammonium bromide (TBABr) and decanoic acid (DecA) was used for the enrichment and extraction of minute quantities of cadmium heavy metal contained in the samples. In order to maximize Cd recovery in the samples, optimization studies of various extraction conditions were carried out, including the molar ratio and volume of HDES, salt amount, solution pH, vortex and centrifugation time. Although the pH value does not vary much between (2–10) under optimum conditions, the ideal working condition is pH (7), and the volume and molar ratio of HDES are found to be 1000 µL and 1:1 (TBABr: DecA), respectively. At the optimized extraction conditions, detection limit (LOD), quantification limit (LOQ), intra-day/inter-day precision (expressed as relative standard deviation %), and enrichment factor (PF) were observed to be 0.7 µg L^-1, 2.3 µg L^-1, 4.1- 4.4%, and 20, respectively. Cd extraction from certified reference materials (CRMs) was used to assess the method’s accuracy, and the resulting findings were successfully compared with certified values. Finally, the developed procedure was applied to a variety of food, and water samples. The amounts of Cd in the examined vegetable samples were found to be 0.73 ± 0.07 µg/g in spinach, 0.37 ± 0.04 µg/g in celery, and 0.44 ± 0.03 µg/g in leeks.