Temperature-controlled liquid-liquid microextraction using a biocompatible hydrophobic deep eutectic solvent for microextraction of palladium from catalytic converter and road dust samples prior to ETAAS determination

A simple method based on temperature-controlled liquid-liquid microextraction (TC-LLME) using a novel hydrophobic deep eutectic solvent (DES) was developed for preconcentration of palladium. Deep eutectic solvent based on phenyl salicylate (salol) and DL-menthol (1:1) was used as the extraction solvent. The control of temperature enhanced the dispersion of deep eutectic solvent and a homogeneous solution was made. Upon cooling the solution in an ice bath, a cloudy solution was formed. Afterwards, the mixture was centrifuged and the sediment phase was analyzed by Electrothermal Atomic Absorption Spectroscopy (ETAAS). To improve the extraction efficiency, the main parameters were optimized. Under the optimized extraction conditions, the limit of detection (LOD) and limit of quantification (LOQ) were 0.03 mu g L-1 and 0.10 mu g L-1 respectively. Preconcentration factor was obtained 191. The precision, expressed as the relative standard deviation (RSD, n = 10), found to be 4.6%. Finally, the method was an effective procedure for the determination of palladium in water, catalytic converter and road dust samples with acceptable extraction recoveries of 95.1% to 100.4%. The obtained results confirmed the ability of the developed method in the different samples.