基于重氮反应测定亚硝酸根的研究—2.5次微分电分析法测定 NO_2^-

Determination of Nitrite Based on the Diazo-Reaction——Determination of Nitrite by the 2.5th Order Differential Electroanalysis

本文研究了在微酸性介质中,磺胺或对氨基苯乙酮与NO_2^-离子重氮化反应的实验条件。建立了一个灵敏、快速测定NO_2^-的分析方法,大量NO_3^-存在不干扰测定。

The experimental conditions were studied to determine nitrite by the 2.5th order differential electroanalysis at DME based on the diazo-reaction. The quantitative method which determines directly the trace amount of nitrite with sulphanilamide and p-aminoacetopheone was recommended. The shape of the c″-E curve, as expected from theory, consists of two maximum peaks and a minimum one. The peak potentials are about -0.20V and -0.23V(vs, SCE)respectively. For the sulphanilamide system, the linear calibration curve was obtained for 5PPb～1. 3PPm. 1000 times NO_3^- ion for the determination of nitrite does not interfere under the experimental conditions. For the p-aminoacetopheone system, the linear range for the determination of nit rite is found to be 10ppb～1. 2ppm. 2000 times NO_3^- ion does not interfere with the determination of nitrite. The methods are simple, rapid, sensitive and reproducible.