水中锑的阻抑动力学光度测定法

Determination of Trace Antimony(Ⅲ) in Water by Inhibitory Kinetic Spectrophotometry

目的建立阻抑动力学光度法定量分析痕量锑(Sb)的新方法。方法在pH值为3.0的醋酸钠-盐酸缓冲溶液中,反应温度为100℃时,痕量Sb3+对过氧化氢(H2O2)氧化劳氏青莲褪色有显著的阻抑作用,于波长610nm处测定阻抑体系吸光度值(Ai)和非阻抑体系的吸光度值(A0),并计算lg(Ai/A0)或ΔA(ΔA=Ai-A0)的值。结果Sb3+浓度在0.4～2.8μg/L范围内,与lg(Ai/A0)值呈良好的线性关系,r=0.9980,其检测限为0.4μg/L,回收率为90%～93.3%。结论该法的线性范围广、准确、灵敏,可用于环境水样中总锑含量的测定。

Objective To establish a new inhibitory kinetic spectrophotometry for determination of trace antimony （Sb^30） in watei based on the inhibitory effect of Sb^3＋ on the oxidated discolouration of Lauth＇s violett. Methods In NaAc-HCl buffer solution, pH 3.0 and reaction temperature was 100℃, trace Sb^3＋ produced remarkable inhibitory effect on the oxidated discolottration of Lauth＇s violet. The absorbances of inhibitory and non-inhibitory systems were determined at 610 nm and lg （Ai/A0） or AA （△A =A i-A 0） were calculated. Results The influence of acidity and coexist anion on the determination was discussed, 1g（Ai/Ao） showed a good linear relation with cSb^3＋ in the range of 0.4-2.8μg/L. The detection limit of the present method was 0.4μg/L and the correlation coefficient was 0.998 0. Conclusion The method has a wide linearity range and is accurate, sensitive, suitable for determination of trace Sb^3＋ in the environmental water samples.