孔雀石绿共振光散射法测定饮用水中痕量BrO_3^-

Determination of trace bromate ion using malachite green as resonance light scattering spectral probe

在pH 3.8的HAc-NaAc缓冲液中,BrO3-氧化I-生成I2,I2与过量的I-反应生成I3-,I3-与孔雀石绿(MG)反应形成缔合微粒,导致体系的共振光散射强度急剧增强,最大共振光散射波长位于465nm处,BrO3-浓度在0～120μg/L范围内有较好线性关系,检出限以3σ计算为3.4ng/mL,据此建立了一种测定微量BrO3-的共振光谱新方法。该法用于饮用水中BrO3-的测定,得到了满意的结果。

A new resonance light scattering（RLS） spectral method was described for the determination of trace bromate ion based on the reaction that bromate ion and excess I-formed I-3 in pH3.8 HAc-NaAc buffer solution.I-3reacted with malachite green to form association particles,which enhanced the RLS intensity greatly.When the concentration of bromate ion was in the range of 0～120μg/L,a good linear relationship was obtained.The resonance light scattering peaked at 465 nm with detection limit（3σ） of 3.4 ng/mL.Hence,a new resonance scattering spectral method which was simple,rapid,highly sensitive was set up.The method had been successfully used to determine the content of bromate ion in drinking water,and the result is satisfactory.