COMPARISON OF CHEMICAL MODIFIERS USED FOR THE DETERMINATION OF GOLD IN ORES BY ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROMETRY

The interference effects of major matrix elements, contained in gold o res (silicate-, oxide-, sulfide-, bismuth- and tellurium-ores) for the determination of gold by electrothermal atomic absorption spectrometr y (ETAAS), were studied. Samples of five one-component (Cu, Mo, Ni, Pd and V) and 12 two-component chemical modifiers composed from above fi ve one-component modifiers were compared for their anti-interference e ffects on the major matrix elements (Al, As, Bi, Ca, Cu, Fe, Mg, Mn, P b, Sb, Te and Zn) in gold ores. A chemical-modifier solution composed of 1000 mg l(-1) each of Ni and V showed the best performance. Gold in five decoppered copper oxide ores was determined by ETAAS with the he lp of the Ni/V chemical modifier without matrix pre-separation. The re lative standard deviation was 3.9% (n=9) for 0.47 mg l(-1) gold. The r ecoveries of added gold (50 mg l(-1)) were 93-102%. The characteristic mass was 12.8 pg. (C) 1998 Elsevier Science B.V.