Determination of gold and palladium in environmental samples by FAAS after dispersive liquid–liquid microextraction pretreatment

A new dispersive liquid–liquid microextraction (DLLME) method is proposed for rapid separation, simultaneous extraction and preconcentration of gold and palladium at ultra trace amounts. The extraction of the analytes was performed in the presence of 5-[(E)-(2,6-diaminopyridine-3-yl)diazenyl]-1,3,4-thiadiazole-2-thiol (DAT) as chelating agent. Chloroform and acetone were used as extraction and dispersive solvents, respectively. The variables affecting the complexation and extraction conditions were optimized. The calibration curves were linear in the range of 1.1–85 and 0.9–124 μg L−1 with the detection limits of 0.4 and 0.6 μg L−1, and with the enrichment factors of 94 and 113 for Au and Pd, respectively. The precision (RSD%) was better than 2.4%. The accuracy of the method was verified by analysing the certified standard reference material (CDN–PGMS-10). The results show that the dispersive liquid–liquid microextraction pretreatment is a sensitive, rapid, simple and safe method for the separation/preconcentration of gold and palladium.