配体竞争络合阴极吸附溶出伏安法测定湖水中铁  

Determination of Iron Complexation in Lake Water by Cathodic Stripping Voltammetry and Ligand Competition

作　　者：董宗木[1] 赵广超[1] 王虎[2] 

机构地区：[1]安徽师范大学环境科学与工程学院,安徽芜湖241003 [2]同济大学海洋与地球科学学院,上海200092

出　　处：《分析科学学报》2013年第1期30-34,共5页Journal of Analytical Science

基　　金：国家自然科学基金(No.20975001);安徽省教育厅基金(No.kj2010B354)

摘　　要：应用2-(2-噻唑偶氮)-对甲酚(TAC)作为络合剂对湖水中铁进行络合吸附形成Fe(TAC)2,在悬汞电极上对水样中Fe(TAC)2进行富集,采用快速线性阴极溶出伏安法获得伏安曲线,实现湖水中游离Fe3+、络合铁和总铁的测定。测定最优化条件是:电解液含5mol/L N-(2-羟2基)哌嗪(EPPS)(pH=8.0),0.1mol/L NaCl,10μmol/LTAC;富集电位为-0.4V;富集时间为8min;扫描速率为10.0V/s。该方法的检出限为0.08nmol/L。加入样品中的TAC和铁形成的复合物的稳定性通过加入另一种竞争络合物EDTA得到α=260,条件稳定常数β′=2.66×1012(mol/L)-2。A simple and precise method was established for determination of iron complexation in lake water by cathodic stripping voltammetry （CSV） with ligand competition using the iron binding ligand 2-（2-thiazolylazo）-p-cresol （TAC）. The sensitivity was improved by employing a fast （10.0 V/s） linear sweep scan waveform on a static mercury drop electrode. The optimized conditions to determine dissolved iron.iron complexation and total iron in lake water by CSV using TAC entails a TAC concentration of 10 /~mol/L,a solution pH of 8.0 with 5 mmol/L 3-[4 （2-hydroxyethyl）-l-piperazinyl] propane sulfonic acid（EPPS） buffer, an adsorption potential of -- 0.4 V, and an adsorption time of 8 min. Under these optimized conditions the limit of detection was 0.08 nmol/L for Fe3＋ exation by TAC （Fe（TAC）2）was calibrated by ligand competition a 260 for a,and 2.66 ×10^12 （mol/L） 2 for the conditional stability constant C galnst （β′）. omplex stability of iron EDTA giving a value of

关 键 词：铁 阴极溶出伏安法 湖水 2-(2-噻唑偶氮)-对甲酚 

分 类 号：O657.15[理学—分析化学]