【摘要】 在盐酸介质中,铌(Ⅴ)与桑色素和吐温-80形成多元络合物,其表观摩尔吸光系数为(ε430)=7.90×104L.mol-1.cm-1,相关系数为0.998 8,铌量在0~0.40 mg.L-1范围内符合比耳定律,用丹宁沉淀法分离Fe3+、Al3+、V(Ⅴ)、W(Ⅶ)、Cr(Ⅵ)、Mn2+等干扰离子,应用于地质、合金样品中微量铌的测定,其相对标准偏差≤4.0%(n=8)。更多还原

【Abstract】 A method of spectrophotometric determination of trace amounts of Nb was described.A ternary complex of Nb（Ⅴ） with 3,5,7,2′,4′-pentahydroxyflavone（morin） and Tween 80 was formed in HCl medium.Beer′s law was obeyed in range of Nb（Ⅴ） concentration of 0-0.40 mg·L^-1 with a correlation coefficient of（0.998 8.） Molar absorptivity of the complex was 7.90×10⁴L·mol^-1·cm^-1 at λ_max 430 nm.After separation of interfering Fe（Ⅲ）,Al（Ⅲ）,V（Ⅴ）,W（Ⅶ）,Cr（Ⅵ） and Mn（Ⅱ） by precipitation with tannin,Nb was successfully determined in complicated geological samples and alloy samples,with RSD≤4.0%（n=8）.更多还原