ICP-AES法测定高温合金中钽的研究

研究了采用ICP-AES法测定高温合金中钽的谱线选择、基体及合金元素的干扰、钽标准溶液的配制以及样品处理对测定结果的影响。确定了240.063 nm作为钽的分析线,在此波长下,高温合金中大量镍、铬、钨、钼、铝、钛、铌等元素不干扰测定,铁、钴的背景影响采用基体匹配办法克服。为了防止钽的水解,钽的标准溶液适宜用氢氟酸和草酸铵介质。溶样时,滴加氢氟酸处理样品可得到稳定结果,此外,采用适宜比例的硝酸和盐酸混合酸溶样后,硫酸冒烟处理也可以得到稳定结果。方法已用于高温合金中钽的测定,相对标准偏差为0.42%~0.97

Study on determination of tantalum in superalloys by ICP-AES

A method for the determination of tantalum in superalloys by ICP-AES was established.By studying on the selection of wavelength,the interference of matrix and coexistent elements,the preparation of tantalum standard solution,and the effect of sample preparation on the results,the experimental conditions were optimized.240.063 nm was selected as the analytical spectral line for tantalum,and Ni,Cr,W,Mo,Al,Ti and Nb did not interfere with the determination of tantalum.The effect originating from the background signal of Fe and Co could be eliminated through matrix matching.If tantalum standard solution was prepared in hydrofluoric acid or ammonium oxalate medium,the hydrolyzation of tantalum could be prevented.Two dissolution manners would be prone to get stable results.One was to add some hydrofluoric acid in drip during dissolving sample and the other was to add sulphuric acid and heat to fumes of SO_3 after dissolution of sample with mixture of HNO_3-HCl.The method has been directly used in the determination of tantalum in superalloys with the RSDs in the range of 0.42%-0.97%.