[Simultaneous determination of impurities in K2CrO4 by ICP-AES]

The trace elements, Ca, Mg, Ba, Co, Cd, Cu, Mn, Pb, Sr, Zn, Al, Fe, Ni, Ti, Si and V, in K2CrO4 were simultaneously determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Optimum spectral lines were selected for each analyzed element. The matrix effect was studied and eliminated through matrix matching. The results show that the linear correlations of standard curves are good (R2 = 0.998 6-1.000) under the determined conditions. The recoveries of standard addition are in the range of 83.7%-113.0%, and the relative standard deviations are lower than 9.48% (n = 9). Detection limits of these impurities are in the range of 0.075-2. 625 mg x kg(-1). The method is rapid, simple, accurate and credible, so it can be used for the determination of impurities in K2 CrO4 product. The results also show that there is relatively high content of Ca, Mg, Al and Si in K2 CrO4 product, so the K2 CrO4 product can't be directly used for the ion membrane electrochemical synthesis of chromic anhydride and the product must be taken for further purification.