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 ores (silicate-, oxide-, sulfide-, bismuth- and tellurium-ores) for the determination of gold by electrothermal atomic absorption spectrometry (ETAAS), were studied. Samples of five one-component (Cu, Mo, Ni, Pd and V) and 12 two-component chemical modifiers composed from above five one-component modifiers were compared for their anti-interference effects on the major matrix elements (Al, As, Bi, Ca, Cu, Fe, Mg, Mn, Pb, 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 help of the Ni/V chemical modifier without matrix pre-separation. The relative standard deviation was 3.9% (n=9) for 0.47 mg l−1 gold. The recoveries of added gold (50 mg l−1) were 93–102%. The characteristic mass was 12.8 pg.