Deep Eutectic Solvent Based Air Assisted Ligandless Emulsification Liquid-Liquid Microextraction for Preconcentration of Some Heavy Metals in Biological and Environmental Samples.

In this study, a deep eutectic solvent (DES) based on air-assisted ligandless emulsification liquid-liquid microextraction method (DES-AA-LL-ELLME) was considered for preconcentration and extraction of some metals (Cd, Ni, Pb and Cu). A 1:1 mixture of the synthesized DES and triethylamine was added as an extractant to extract metal ions in the absence of chelating agent. Tetrahydrofuran as the aprotic solvent provided a turbid state. To disperse the aggregated DES droplets into the aqueous phase, air-assisted was performed. The influence of several effective parameters was monitored. Under optimum conditions, limits of detection were found in the range of 0.31-0.99 µg L-1 with preconcentration factor from 67 to 69. The relative standard deviation (n = 10) was in the range of 2.1%-3.1% for all analytes. This procedure was applied to determine some metals in both biological and environmental samples with appropriate recoveries about 98.7%-106%.