Polarographic Determination of Palladium(II) in Rocks After Extraction with [5-(4-Dimethylaminebenzylidene)rhodanine] and Methyl Isobutyl Ketone

A sensitive and selective method for the determination of palladium(II) in mineral veins of quartz, a pegmatite rock from Campo Largo County, Parana State, Brazil, was investigated. After liquid-liquid extraction of Pd 2- from aqueous solution, pH 2.4, with [5-(4-dimethylaminebenzylidene)rhodanine] and methyl isobutyl ketone, the back-extraction was performed with 3.0 mol.L −1 sulfuric acid. At pH 2.4, only trace amounts of gold(III) and silver(I) were co-extracted with palladium(II). However, neither Au 3+ nor Ag + interfere with palladium(II) determination by differential pulse polarography using tris(hydroxymethyl)aminomethane and potassium nitrate, pH 11.0, as supporting electrolyte. The observed detection limit was 1.0 μg(Pd 2+ ).L −1 .