摘要
研究并建立了砷锑钨三元杂多酸体系导数示波极谱测定微量砷的新方法。在硫酸（１．０ｍｏｌ／Ｌ）－丙酮（２５％）溶液中，于５０℃，Ａｓ（Ｖ）和Ｓｂ（Ⅲ）及Ｗ（Ⅵ）形成具有电活性的砷锑钨三元杂多酸；在硫酸（０．４ ｍｏｌ／Ｌ）－丙酮（１０％）介质中，于－０． ３７ Ｖ（ｖｓ ＳＣＥ）产生一灵敏的还原峰，灵敏度比同类方法提高 １０倍。其二次导数电流峰高（ｉｐｎ）与砷量在 ５． ３ × １０－９～５． ３×１０－７ｍｏｌ／Ｌ范围内呈线性关系。相关系数（ｒ）和检出限分别为０．９９９８和２．８×１０－９ｍｏｌ／ＬＡｓ（Ｖ）。已用于高温合金（经蒸馏分离）和饮用水样（不须分离）中微、痕量砷的测定，结果满意。文中还详细研究了该杂多酸的电化学行为、络合性、电流特性和电极反应机理．
A new derivative oscillopolarographic method based on the arsenic(V )-antimony (Ⅲ)-tungsten(Ⅵ) ternary heteropoly acid system for the determination of trace arsenic has been initially studied and suggested in this paper. In the medium of sulfuric acid (1. 0 mol/L) containing acetone(25%), arsenic(V) reacted with antimony(Ⅲ) and tungsten (Ⅵ) in the temperature of 50℃ to form an electroactive ternary heteropoly acid, and then a sensitive reduction peak current appeared at-0. 37 V (vs. SCE) in the medium of sulfuric acid (0. 4 mol/L) containing acetone (10%). The sensitivity was increased about 10 times compared with that of the methods of the same kind. The second derivative current peak height (ipn) was proportional to the concentration of arsenic (V ) in the range of 5. 3 X 10-9-5. 3 X 10-7 mol/L. The correlation coefficient(r) and the detection limit were 0. 9998 and 2. 8 X 10-9 mol/L As(V ), respectively. The proposed method has been applied to determine the micro and/or trace amounts of arsenic in superalloy (after separation) and in drinking water (without separation) with satisfactory results. Moreover, the electrochemical behavior, the complexity, the current character and the electrode reaction mechanism of this heteropoly acid were investigated in details.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
1998年第6期742-747,共6页
Chinese Journal of Analytical Chemistry
基金
国家自然科学基金
关键词
三元
示波极谱
砷锑钨杂多酸
砷
测定
分析
Ternary heteropoly acid of arsenic (V)-antimony (Ⅲ)-tungsten (Ⅵ), complex adsorptive wave, oscillopolarography, electrode reaction
