邻苯三酚红固相萃取光度法测定微量铌  

Solid phase extraction and spectrophotometric determination of micro niobium with pyrogallol red

作　　者：李慧芝[1] 庄海燕[1] 许崇娟[1] 

机构地区：[1]济南大学化学化工学院,山东济南250022

出　　处：《冶金分析》2009年第4期50-53,共4页Metallurgical Analysis

基　　金：山东省自然科学基金资助项目(No.Y2000B09)

摘　　要：在pH6.5的六次甲基四胺-盐酸缓冲介质中,在溴化十六烷基三甲基铵(CTMAB)存在下,邻苯三酚红与铌(Ⅴ)反应生成摩尔比为2∶1的稳定络合物,该络合物可用717型阴离子交换树脂固相萃取柱富集,再通过树脂相测定铌,由此建立了固相分光光度法测定铌的新方法。吸附络合物的树脂相的最大吸收波长为530nm,表观摩尔吸光系数ε=4.35×105L.mol-1.cm-1。铌含量在0.01～0.4μg/mL内符合比尔定律,相关系数r=0.9981。对30余种共存离子进行试验,结果表明大多数常见离子不干扰测定。方法用于合金、钢铁等样品中铌的分析,结果与认定值相吻合,相对标准偏差小于5.0%。A new method for the determination of micro niobium by solid phase extraction spectrophotometry was established. In the presence of CTMAB and hexamethylene tetramine （C6H12 N4）-HCl buffer solution （pH 6.5）, the reaction of pyrogallol red with niobium （Ⅴ） would produce a stable complex （2 ： 1） which could be adsorbed on the 717# anion-exchange resin solid phase extraction column. Then, niobium could be determined with resin solid phase extraction spectrophotometry. The maximum wavelength of resin phase for adsorbing the complex was 530 nm and the apparent molar absorptivity ε was 4.35×10^5 L ·mol^-1 · cm^-1. Beer＇s law was obeyed in the range of 0.01-0.4μg/mL for Nb（Ⅴ ）,and the correlation coefficient r was 0. 998 1. More than 30 co-existing ions were tested and the results showed that most ions had no interference in the determination. The proposed method can be applied to the determination of niobium in alloy and steel samples. Its result was in accordance with the certified value and the relative standard deviation was less than 5.0 %.

关 键 词：固相萃取 邻苯三酚红 铌(Ⅴ) 分光光度法 

分 类 号：TG115.33[金属学及工艺—物理冶金]