The Research Of Analytical Methods On The Determination Of Impurities In High-purity Tantalum Niobium Compound By ICP-OES

High-purity tantalum and niobium compounds are the raw material of making capacitor and optical flat etc.. Tantalum and niobium compounds are requested to be more and more pure in order to meet the final product. There are limited reports on analytical method of high-purity tantalum and niobium compounds. Though arc atomic emission spectrometry had been used, because of low sensitivity of partial elements and limitation by standard substance, the applicability of method is poor. Methods have been proposed for the determination of trace impurities in high-purity tantalum niobium pentoxide and potassium fluotantalate etc. by ICP-OES in this paper. The direct method, cation exchange, hydride generation ICP-OES were discussed in order to remove the matrix interference in the trace analysis .The methods can meet the specification of product and economic benefits and social benefits.The matrix was matched to calibration curve in order to remove the matrix interference for the direct determination of impurities in high-purity tantalum pentoxide and potassium fluotantalate, and the operation condition of the instrument was optimized. The limits of detection are 1μg/g for Ca, Mg, Mn, Ti; 2μg/g for B, Cr, Cu; 5μg/g for Al, Fe, Mo, Nb, Ni; 10μg/g for W. The accuracy of the results obtained is confirmed by the determination of trace elements after amatrix standard addition procedure. The method is accurate, rapid and applicable to routine analysis.The direct ICP-OES has been developed for determination of impurities in high-purity niobium pentoxide. The spectral interference by niobium emission at the analytical wavelength and the matrix effect have been studied. The matrix matched to calibration curve and off-peak background corrections were discussed to remove the matrix interference. The limits of detection is 0.5 u g/gfor Mg, Mn, Ti, Zr, Sr; 1 n g/gfor Ag, B, Ca, Fe, Y, Zn; 2 u g/g for Co, Cd, V; 5 u g/gfor Cr, Ga, Hf, Ni; 10 u g/g for Al, Bi, Cu, Mo; 20 u g/g for W, Ta. The standard addition sample test for Ag, Al, B, Fe, Ga, Hf, Mo, Ta, Ti, V, W, Y, Zr confirms that the recovery is 90%-110% in relation to 5 u g/g.The method was developed for determination of impurity elements in high-purity niobium pentoxide by cation exchange ICP-OES. The separation efficiency of niobium matrix and the interference of residual niobium have been tested. The optimized seperation conditions are 4% fluorhydric acid resolving sample and 35mL 4mol/LHNO3 as eluant. The recovery is 82%-115% and RSD is below 10% in relation to 0.2 u g/g-5The method has been proposed for determination of As, Bi, Sb, Se, Sn, Te in high-purity niobium pentoxide by HG-ICP-OES. The matrix interference has been studied. The operation condition has beenoptimized. The LOD is 1 u g/g for As, 0.1 u g/g for Bi, 0.2 u g /g for Se, 3 H g/g for Te. The RSD of below 10%, the discovery of 90%-120% have been obtained as to 2 u g/g.The interference of tantalum, niobium compound has been studied. The spectral interference and non-spectral interference of tantalum niobium compound have been discussed. The reason of producing interference has been discussed and the method of removing interference has been presented.