Determination of As, Cd, Ni, Mn, Fe, Pb, Cu and Co in Waste Water of Zinc Sulfate by ICP-AES after Coprecipitation with Zirconium Hydroxide

A zirconium hydroxide coprecipitation method for the determination of As, Cd, Ni, Mn, Fe, Pb, Cu and Co by inductively coupled plasma atomic emission spectrometry in waste water of feed additive zinc sulfate has been investigated. The coprecipitation conditions, such as the effect of the amount of zirconium solution, the aged time of precipitation, the enrichment factor and the possible matrix ions were examined in detail for the studied elements. It was found that arsenic, cadmium, nickel, manganese, iron, lead, copper and cobalt are coprecipitated quantitatively with zirconium hydroxide at pH 7 with low R.S.D. values of around 1 to 5%. The recovery of all the elements was more than 95%. The detection limits (3s ) of these elements were found in the range from 0.000 6 to 0.0075 μg·mL^-1. The method was successfully applied to the determination of trace elements in some waste water. They were in good agreement with that obtained by the reference ICP-MS method.