Ultrasound-assisted supramolecular dispersive liquid-liquid microextraction based on solidification of floating organic drops for preconcentration of palladium in water and road dust samples

A novel ultrasonic-assisted supramolecular dispersive liquid-liquid microextraction based on solidification of a floating organic droplet (UASMDLLME-SFO) was proposed for the microextraction of Pd(II) prior to its determination by flame atomic absorption spectrometry (FAAS). A supramolecular solvent made up of reverse micelles of 1-dodecanol in tetrahydrofuran (THF) was injected into the aqueous sample solution. Reverse micelle coacervates were produced in situ through self-assembly processes. Sonication accelerated mass transfer of the target analyte into the supramolecular solvent phase. Some parameters such as type and volume of the extraction solvent pH, volume of the disperser solvent, ultrasound extraction time, reagent concentration, and salt concentration were investigated. Under optimum conditions, a detection limit 0.63 pg L-1 with preconcentration factor of 93 and the relative standard deviation (RSD, n = 10) 3.2% were achieved. The accuracy of the method was confirmed by analyses using the geological standard reference materials (GBW07291peridotite). The recoveries of the analytes in water and road dust samples were in the range of 96-104%. (C) 2015 Elsevier B.V. All rights reserved.