苯胺蓝-溴酸钾体系催化分光光度法测定水中痕量亚硝酸盐

Catalytic Spectrophotometric Determination of Trace Amount of Nitrite in Water Using Reaction System of Aniline Blue and Potassium Bromate

摘要: 在硫酸介质中,亚硝酸盐对溴酸钾氧化苯胺蓝褪色反应有明显的催化作用,据此提出了测定痕量亚硝酸盐催化分光光度方法。优化的试验条件如下:① 1.0 mol·L-1硫酸溶液的用量为1.8 mL;② 3×10-4mol·L-1苯胺蓝溶液用量为1.5 mL;③ 0.02 mol·L-1溴酸钾溶液用量为1.1 mL;④ 反应温度为30 ℃。该方法的线性范围分别为0.01~0.2 mg·L-1和0.2~1.0 mg·L-1,检出限(3s/k)为4.6×10-6g·L-1。方法用于水样的分析,回收率在96.0%~104%之间,测定值的相对标准偏差(n=6)在1.6%~2.3%之间。

Abstract: In H2SO4 solution, the oxidative fading reaction of potassium bromate was catalyzed by nitrite. Based on this reaction, a catalytic spectrophotometric method for the determination of trace amount of nitrite was proposed. The optimized conditions were as follows: ① amount of 1.0 mol·L-1 H2SO4 solution: 1.8 mL; ② amount of 3×10-4mol·L-1 aniline blue solution: 1.5 mL; ③ amount of 0.02 mol·L-1 potassium bromate solution: 1.1 mL; ④ temperature of reaction: 30 ℃. The linearity were in the ranges of 0.01-0.2 mg·L-1 and 0.2-1.0 mg·L-1 with detection limit (3s/k) of 4.6×10-6g·L-1. The proposed method was applied to the analysis of water sample, giving values of recovery and RSD′s (n=6) in the ranges of 96.0%-104% and 1.6%-2.3% respectively.