曲利本兰分光光度法测定微量亚硝酸根

盐酸介质中,曲利本兰与NO2-反应后发生颜色变化,最大褪色波长位于600 nm,此波长处体系吸光度的降低与溶液中NO2-的浓度成正比,在0.04~1.2 mg/L NO2-范围内符合比耳定律,线性关系良好。方法具有较高的灵敏度,检测限为0.018 mg/L。共存物质的影响研究表明方法选择性好。用于环境水中微量NO2-的测定,结果满意。

Spectrophotometric Determination of Trace Nitrite with Trypan Blue

A new spectrophotometric method for the determination of trace nitrite was studied. The method was based on the reaction of Trypan blue with nitrite in diluted hydrochloric acid medium, which the colour of the solution changed obviously from deep to shallow. The maximum fading wavelength of the absorption band was at 600 nm. The linear range for the determination was 0.04 - 1.2 mg/L NO2-. The detect limit for the nitrite was 0.018 mg/L. The method also had good selectivity, and could be applied to the determination of nitrite in water with samples satisfactory results. The recoveries were 93.5 %- 98.1%.