Simultaneous determination of seven impurities in high-purity cobalt oxide by ICP-AES after matrix separation using 1-nitroso-2-naphthol as a precipitant

摘要

A method was developed for the simultaneous determination of seven trace impurities (Cd, Mn, Pb, Zn, Cu, Fe and Ni) in high-purity cobalt oxide by ICP-AES. The matrix effect was eliminated by precipitation with 1-nitroso-2-naphthol. The matrix effect of cobalt on the absorptions of trace impurities, the effects of reaction time. pH value, dosage of precipitant on the formation of cobalt-1-nitroso-2-naphthol complex, the effects of hydrochloric acid on the stability of this complex and masking of elements were studied. Recoveries of the impurities in spiked sample are from 90 percent to 110 percent with a precision of 1.1 percent-5.0 percent RSD. The detection limits of the seven elements are in the range of 0.01-0.24mug/ g. The method can be applied to the analysis of high-purity cobalt metal, cobalt oxide and other cobalt cobalt compounds.