溴酸钾氧化溴酚蓝催化光度法测定亚硝酸根

Catalytic spectrophotometry for determination of trace nitrite based on catalytic oxidation of bromophenol blue by bromate

以磷酸介质中亚硝酸根催化溴酸钾氧化溴酚蓝为指示反应 ,通过条件选择 ,建立了催化光度法测定痕量亚硝酸根的新方法 .在 90℃恒温水浴中加热反应 1 0min ,测定亚硝酸根的线性范围为 0 .0 1～ 0 .6 0 μg/2 5mL ,测定下限低达 8× 1 0 -11g/mL.所拟定分析方法已直接应用于环境水样中超痕量亚硝酸根的测定 .

A new catalytic method is for determination of trace nitrite. It is based on the catalytic action of nitrite on a new indicative reaction the oxidation deceleration of bromophenol blue by potassium bromate in dilute phosphoric acid. The reaction rate is monitored spectro-photometrically by measuring the absorbency at 600 nm after quenching the reaction with sodium hydroxide. Fixing the reaction time as 10 min, a calibration graph from 0.01 to 0.60 μg / 25 mL of nitrite and a detection limit of 8 ×10 -11 g /mL is obtained. The proposed method has been applied successfully to the determination of trace nitrite in some natural waters.