Use of deep eutectic solvent-based air-assisted emulsification liquid-liquid microextraction of palladium and determination by flame atomic absorption spectrometry in water and environmental samples

A simple, efficient, green, and sensitive enrichment method is presented for the determination of palladium (II) in water and environmental samples using deep eutectic solvent-based air-assisted emulsification liquid– liquid microextraction (DES-AA-ELLME) and flame atomic absorption spectrometry for analysis. In this procedure, the Pd(II) extraction was obtained using 2-hydroxy-3-methoxybenzaldehyde thios-emicarbazone (HMBATSC) a complexing agent, tetrahydro-furan (THF) and choline chloride-phenol as emulsifier, and extraction solvents, respectively. The various analytical parameters, including type and molar ratio of the deep eutectic solvent, pH, amount of ligand, and pulling and pushing of the syringe, were studied and optimized. In the experiments, the optimal conditions, analytical characteristics of the investigated method and the limit of detection (1.2 µg L⁻¹), relative standard deviation (3.6 %), linear range (4 to 500 µg L⁻¹), and preconcentration factor (70) were measured. The accuracy of the DES-AA-ELLME method was confirmed with a certified reference material (NIST SRM 2557 Catalyst). The developed method was satisfactorily applied to real water samples with the standard addition method as well as acid-digested environmental samples.