靛蓝二磺酸钠褪色分光光度法测定水中臭氧

Spectrophotometric Determination of Ozone in Water by the Color-Fading Reaction of Sodium Indigo Disulfonate

摘要: 在pH 2.0的磷酸-磷酸氢二钠缓冲溶液中,臭氧可使靛蓝二磺酸钠溶液褪色,且褪色程度与臭氧含量呈线性关系,据此提出了测定水中臭氧的方法。试验结果表明:靛蓝二磺酸钠的最大吸收波长为610 nm,臭氧的质量浓度在0.12~3.0 mg·L-1范围内与吸光度变化值呈线性,表观摩尔吸光率为1.8×104L·mol-1·cm-1。应用此方法测定了水中臭氧的含量,测得相对标准偏差(n=20)在0.6%~2.8%之间。

Abstract: In a H3PO4-Na2HPO4 buffer medium of pH 2.0, fading of color due to the reaction of sodium indigo disulfonate with ozone was observed. It was found that the magnitude of decrease in absorbance measured at 610 nm kept a linear relationship with the concentration of ozone in the range of 0.12-3.0 mg·L-1. Apparent molar absorptivity of the reaction system was found to be 1.8×104L·mol-1·cm-1. Based on these facts, a spectrophotometric method for determination of ozone in water was proposed. Water samples were analyzed by the present method, giving values of RSD′s (n=20) in the range of 0.6% to 2.8%.