Deep eutectic solvent (DES) with silver nanoparticles (Ag-NPs) based assay for analysis of lead (II) in edible oils

This paper presents an application of silver nanoparticles impregnated by Deep Eutectic Solvents (DES) as ultrasonication aided microextraction system for lead (II) determination in edible oils. The paper presents a systematic optimization of method parameters and examples of its application for analysis of real samples. Maximum recovery for lead (II) extraction was obtained for choline chloride and phenol with a 1:2 M ratio. Optimum extraction conditions for 2 g oil sample post-digested solution (10 mL, pH = 2) require 1 mL of Ag-nanoparticles solution (0,1mM) and per each 500 µL of DES and tetrahydrofurane. The limit of detection (LOD) and quantification (LOQ) were 0.28 µg/L and 0.94 µg/L. The developed method covers the entire range of expected levels of lead concentration in oil samples -parts per billion levels to higher ones. This method is many folds faster (only 6.5 min/sample are needed) as well as more sensitive comparing to already reported methods.