铌-铬天青S-氯代十六烷基吡啶体系光度法测定铌

SPECTROPHOTOMETRICDETERMINATIONOFNIOBIUMBYTHE REACTION SYSTEM OF Nb(Ⅴ)-CAS-CPC

研究了铌与铬天青Ｓ及氯代十六烷基吡啶的显色反应及其应用。试验表明：在六次甲基四胺盐酸缓冲液中，Ｎｂ（Ⅴ）－ＣＡＳ－ＣＰＣ形定稳定的三元配合物，最大吸收波长为５２０ｎｍ，表观摩尔吸光系数为３４１×１０５Ｌ／ｍｏｌ·ｃｍ。铌浓度在０～０４４μｇ／ｍＬ范围内符合比尔定律，基于此建立测铌的新方法，考察了３０种共存离子的影响，结果表明干扰较少，该方法可用于矿样和合金钢中铌的测定。

The colour-reaction and its application of Nb(Ⅴ) with CAS and CPC have been studied.It was found that a ternary complex was obtained by the reaction between Nb(Ⅴ),CAS and CPC in(CH2)6N4-HCl buffer solution.The complex has a maximum absorption at 520nm with a molar absorptivity of 341×105 L/mol·cm.Beers law is obeyed for Nb(Ⅴ) in the range of 0～044 μg/mL .The effects of 30 foreign ions were sudied and the method is free from most interferences.The method has been applied to the determination of Nb(Ⅴ) in mineral and alloy steel with satisfactory results