钼催化-共振瑞利散射光谱法测定痕量溴酸根

Resonance Rayleigh Scattering Determination of Trace Bromate in Drinking Water Using Polyvinyl Alcohol-Boric Acid-iodine System

在盐酸介质及硼酸存在条件下,Mo（VI）催化溴酸根离子氧化I-形成I2,I2与硼酸及聚乙烯醇（PVA）反应形成蓝绿色络合物,在670nm处有一个最大吸收峰,在369nm处有一个最大共振瑞利散射峰。在选定的条件下,其吸光度和共振瑞利散射强度随着溴酸根浓度增大而线性增强,由此建立了光度法和共振瑞利散射法测定饮用水中溴酸根的新方法。BrO-3质量浓度分别在0.1-2μg/L和1-30μg/L与共振瑞利散射强度增大值ΔI和吸光度增大值ΔA呈线性关系,检出限分别为0.05μg/L和0.5μg/L。采用共振瑞利散射光谱法测定饮用水中的溴酸根,得到了满意的结果。

In hydrochloric acid medium containing boric acid, Mo（VI） catalyzed bromate oxidation ofiodine ion to form iodine, and then it reacted with polyvinyl alcohol to form blue green complex. Itexhibited a maximum absorption peak at 670 nm, and a maximum resonance scattering peak at 369nm.In the selected conditions, there was a good linear relationship between the absorbance and resonanceRayleigh scattering intensity and the concentration of a certain range of bromate. Therefore, two newmethods of determination of bromate were put forward in drinking water with spectrophotometry andresonance Rayleigh scattering. By using the spectroph0tometric method, the regression equation was AA---- 0.086pr --0.013, the linear range was from 1 to 30 μg/L, with a detection limit of 0.5 μg/L. Byusing the resonance Rayleigh scattering method, the regression equation was AI =406.44pro ＋36.36,the linear range was from 0.1 to 2 μg/L, with a detection limit of 0.05μg/L. Bromate in drinking waterwas determined by using resonance Rayleigh scattering method with satisfactory results.