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 Large County , Parana State, Brazil, was investigated. After liquid-liquid extracti on of Pd2+ from aqueous solution, pH 2.4, with [5-(4-dimethylaminebenz ylidene)rhodanine] and methyl isobutyl ketone, the back-extraction was performed with 3.0 mol.L-1 sulfuric acid. At pH 2.4, only trace amoun ts of gold(III) and silver(I) were co-extracted with palladium(II). Ho wever, neither Au3+ nor Ag+ interfere with palladium(II) determination by differential pulse polarography using tris(hydroxymethyl)aminometh ane and potassium nitrate, pH 11.0, as supporting electrolyte. The obs erved detection limit was 1.0 mu g(Pd2+).L-1.