Emulsification liquid-liquid microextraction method based on a deep eutectic solvent for separation and preconcentration of lead from environmental water samples

In this paper, a novel emulsification liquid-liquid microextraction method based on deep eutectic solvents (DESs) for the preconcentration of lead from water samples and its determination by flame atomic absorption spectrometry is described. Purpurin was used as complexing ligand and the Pb(II)-purpurin complexes were extracted and preconcentrated from the aqueous phase using a choline chloride/2-chlorophenol (at a 1:2 molar ratio) based DES as a water-miscible extraction solvent and tetrahydrofuran as an emulsifier solvent. Some analytical parameters affecting the extraction yield were investigated and optimized. Using a 20 mL aqueous sample, the limit of detection and preconcentration factor of the method were 5.93 mu g L-1 and 20, respectively. The accuracy of the method was assessed through the analysis of certified reference surface water (SPS-SW2 Batch 127) and spiked water samples. The certified and obtained values were statistically in good agreement at 95% confidence level. The recovery values of spiked water samples were between 102% and 105%.