Determination of Nickel, Zinc and Cobalt in Advanced Materials Based on NixCo3 –xO4 and ZnxCo3 –xO4 by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and X-Ray Fluorescence

Abstract

An approach to analysis of advanced sensor materials based on cobalt oxide modified with zinc or nickel oxides is developed using X-ray fluorescence analysis (XRF) and inductively coupled plasma mass spectrometry (ICP-MS). It is shown that determination of Ni, Zn, and Co in novel materials based on cobalt oxide using ICP-MS in solutions is possible, the standard deviation being 0.06, 0.06, and 0.05, respectively. The results of the ICP-MS determination of the elements in solutions are used to certify the results obtained by the XRF method without sample preparation. It is shown that Ni_xCo_{3 –x}O_{4 – δ} samples can be correctly analyzed without decomposition using X-ray fluorescence analysis. The results of the determination match theoretically calculated values for the samples obtained both from nitrates and from oxalates of nickel and cobalt. However, calibration based on the ICP-MS results is necessary for X-ray fluorescence analysis of Zn_xCo_{3 –x}O₄ samples. It is shown that the zinc content in the samples exceeds the theoretical determined value by 10–30% because of incomplete precipitation of cobalt from the solution upon synthesis.