锡(Ⅳ)-没食子酸-钒(Ⅳ)体系极谱吸附催化波的研究

Studies on the Polarographic Adsorptive Catalytic Wave of Tin(Ⅳ)\|Gallic Acid(GA)\|Vanadium(Ⅳ) System

在ｐＨ ２．３ 的氯乙酸盐缓冲液中，Ｓｎ（Ⅳ）－没食子酸（ＧＡ）－Ｖ（Ⅳ）体系产生一灵敏的吸附平行催化波，峰电位为－ ０．５０ Ｖ（ｖｓ．ＳＣＥ），二次导数峰高与锡浓度在６．７×１０－ １０～１．７×１０－ ６ ｍ ｏｌ／Ｌ 范围内呈良好线性关系，检测限达３×１０－ １０ ｍ ｏｌ／Ｌ。本文用循环伏安法等电化学方法研究了催化波的性质及电极反应机理。方法已成功地应用于罐头食品中微量锡的测定，结果满意。

In chloracetate buffer solution(pH 2.3), Tin(Ⅳ)\|Gallic acid(GA)\|Vanadium(Ⅳ) system produces a sensitive polarographic adsorptive catalytic wave with peak potential at -0.50 V (vs. SCE). The second\|order derivative peak height is propor\| tional to the concentration of Sn(Ⅳ) over the range from 6.7×10\+\{-10\} mol/L to \{1.7\}×10\+\{-6\} mol/L. The detection limit for Sn(Ⅳ) is as low as 3×10\+\{-10\} mol/L. The properties of the catalytic wave and the electrode process mechanism have been studied by cyclic voltammetry and other electrochemical techniques. The proposed method has been applied to the determination of Sn(Ⅳ) in canned food with satisfactory results.