摘要
研究了锌 （Ⅱ）-2-（5-溴-2-吡啶偶氮）-5-二乙氨基酚-亚硝酸钠[Zn （Ⅱ）-5-Br-PADAPNaNO2]三元络合物在碳糊电极（CPE）上的电化学行为,并建立了测定痕量锌的方波伏安法（SWV）。实验表明：在pH 5.4的六次甲基四胺-盐酸缓冲溶液中,当5-Br-PADAP浓度为3.0×10^-5 mol/L,NaNO2浓度为5.0×10^-5 mol/L,振幅为0.025V,频率60Hz时,于-0.40V（vs.SCE）富集45s后,以100mV/s的扫速在-0.40~0.60V区间内用SWV进行扫描,Zn （Ⅱ）-5-Br-PADAP-NaNO2络合物在0.292V（vs.SCE）有一灵敏的吸附氧化峰。锌浓度在5.0×10^-9~5.0×10^-6 mol/L范围内与络合物的峰电流Ip呈现良好的线性关系,线性相关系数为0.998 9,检出限为1.7×10^-9 mol/L。方法用于环境水和管网水中痕量锌含量的测定,测得结果与双硫腙光度法测定值基本一致,相对标准偏差（RSD,n=6）为1.9%~2.5%,回收率在97%~105%之间。
The electro-chemical behavior of a ternary complex zinc（Ⅱ）-2-（5-bromo-2-pyridylazo）-5-diethyl- amino phenol-sodium nitrate [Zn（Ⅱ）-5-Br-PADAP-NaNO2] on carbon paste electrode （CPE） was studied, and a method of square wave voltammetry （SWV）for the determination of trace zinc was established. The experiments indicated that, in hexamethylene tetramine-hydrochloric acid buffer solution at pH 5.4, when the concentration of 5-Br-PADAP and NaNO2 was 3.0×10^-5 mol/L and 5.0×10^-5 mol/L respectively with amplitude as 0. 025 V and frequency as 60 Hz, Zn（II）-5-Br-PADAP-NaNO2 complex produced a sensi- tive adsorption oxidation peak at 0. 292 V（vs. SCE） after enrichment of 45 s at -0.40 V（vs. SCE） and scanning in the range of --0.40 V to 0.60 V at the scan rate of 100 mV/s by SWV. The concentration of zinc showed a good linear relationship with the peak current Ip of the complex within the range of 5.0 ×10^-9-5.0×10^-6 mol/L, with linear correlation coefficient of 0. 998 9. The detection limit was 1.7X 10.9 mol/L. The method has been applied to determine trace zinc in environmental water and tap water. The results were consistent with those obtained by dithizone photometric method, and the relative standard deviations （RSDs,n=6） were 1.9%-2.5%. The recoveries were 97%-105%.
出处
《冶金分析》
CAS
CSCD
北大核心
2015年第3期37-41,共5页
Metallurgical Analysis
基金
陕西省科技厅项目(2010JM2017)
陕西省教育厅项目(2010JK925
2012JC26)项目
榆林市科技局项目(Gg09-2-05)
榆林学院(10GK02)项目
关键词
锌
电化学行为
碳糊电极
方波伏安法(SWV)
三元络合物
zinc
electrochemical behavior
carbon paste electrode
square wave voltammetry（SWV）
ternary complex
