碳酸盐碱性体系中单宁与Fe(Ⅲ)离子配位稳定常数的分析  

Analysis of Stability Constants of Fe(Ⅲ)–Tannin Complexation in Carbonate Alkali System

作　　者：曹家兴[1] 裴锐南[1] 薛敏华[1] 莫友彬 

机构地区：[1]广西大学化学化工学院,广西南宁530004 [2]广西化工研究院,广西南宁530001

出　　处：《化工技术与开发》2010年第10期10-13,3,共5页Technology & Development of Chemical Industry

摘　　要：在碳酸钠碱性体系中,采用等摩尔递变光度法测定了单宁酸与铁离子形成配合物的组成比为2:1,条件配位稳定常数lgK’=10.22,配合物的最大吸收波长在500 nm;同时采用pH电位滴定法测定单宁酸与铁离子的配位稳定常数lgK=25.54;文中对二者在数值上的差异作了分析,其中配体酸效应系数2?lgαHL=13.1,铁离子水解效应系数lgαFe=2.22。This paper presented the results concerning the determination of the stability constants of the complexes between tannin and Fe（Ⅲ）. The experimental procedure was carried out by UV-vlsible spectrophotometry and pH potenfiometric titration. The formation of tannin to Fe（Ⅲ） was 2：1, the conditional stability constant logK＇ of Fe （Ⅲ）-tannin was 10.22, in the presence of a carbonate buffer at 25 ℃, by the spectrophotometric method. The complexafion constanted log K =25.54 obtained by pH potentiometric titration. The influence from acid effect of tannin and hydrolysis of Fe（Ⅲ） in the alkali carbonate solution had been considered, 2.1ogαHL=13.1 and logαFe=2.22 respectively.

关 键 词：单宁酸 铁离子 PH电位滴定法 紫外可见分光光度法 配位稳定常数 

分 类 号：O641.4[理学—物理化学]