Solvent-based de-emulsification dispersive liquid-liquid microextraction of palladium in environmental samples and determination by electrothermal atomic absorption spectrometry.

A new simple, rapid and efficient sample pretreatment technique for simultaneous extraction and preconcentration was developed. In this study, solvent-based de-emulsification dispersive liquid-liquid microextraction (SD-DLLME) was developed for preconcentration and highly sensitive determination of Pd(II) using the electrothermal atomic absorption spectrometry. The extraction of Pd(II) was performed in the presence of Thio-Michler's ketone (TMK) as the complexing agent. After dispersing, when an aliquot of acetonitrile was introduced as a chemical demulsifier into the aqueous bulk, the obtained emulsion cleared into two phases quickly. Therefore, an extra centrifugation step is not needed for phase separation. Several factors that influence the microextraction efficiency and ETAAS signal, such as pH, TMK concentration, counter ion, extraction time, disperser, de-emulsifier solvents and extraction solvents, stirring rate, pyrolysis and atomization temperature were investigated. Under the optimized conditions, the calibration graph was linear over the range of 0.025-0.500 μg L(-1) and relative standard deviation of 3.68% at 0.1 μg L(-1) was obtained (n=7). The limit of detection and the enrichment factor (EF) were obtained 0.007 μg L(-1) and 231, respectively. The obtained results indicated that the developed method is an excellent alternative for the routine analysis in the environmental field.