2Grebneva O N, Shchetinina N I, Kubrakova I V. Kudinova T inductively coupled plasma atomic emission determination of impurities in high purity niobium and tantalum oxides after separation of the matrix on a polyorgs Ⅶ sorbent[J]. Journal of Analytical Chemistry, 1998,53(1) :79.
3Grebneva O N, Kubrakova I V, Kudinova T F, et al. Direct determination of trace elements in niobium, tantalum and their oxides by inductively coupled plasma atomic emission spectrometry after microwave dissolution[J]. Spectrochimiea Acta, Part B: Atomic Spectroscopy, 1997,52(8) :1151-1159.
