Determination of gold, platinum, palladium and silver in geological samples by inductively coupled plasma atomic emission spectrometry after poly(dithiocarbamate) resin pre-treatment

Abstract

Because of their low natural abundance, gold, platinum, palladium and silver were separated from their geological matrix and pre-concentrated after sample fusion with a lithium borate flux preceeding their determination by inductively coupled plasma atomic emission spectrometry (ICP-AES). The fused samples were dissolved in nitric acid and the solution was treated with a poly(dithiocarbamate) resin to separate analytes from the matrix elements. Chelated elements were determined by ICP-AES after digestion of the resin. The dependence of the resin uptake on pH for both analyte and matrix elements, including iron and silicon, was investigated and the optimum pH ranges were compared for poly(dithiocarbamate), poly-(acrylamidoxime) and 1-(2-pyridylazo)-2-naphthol (PAN)-impregnated XAD-4 resins. Gold, platinum, palladium and silver were determined in a geological standard material.