基于亚硝化反应分光光度法测定亚硝酸根

本文研究了在酸性介质中吖啶红与亚硝酸根发生亚硝化褪色反应的条件 ,建立了光度法测定亚硝酸根的新方法。最大吸收波长 5 2 5nm处的ΔA与亚硝酸根浓度在 0 0 2 5～ 0 5 μg·mL-1范围内成线性关系。用于水中NO-2 的测定 ,结果满意。

Spectrophotometric Determination of Nitrite Ion with Acridine Red Based on the Nitrosation Reaction

A new spectrophotometric method for the determination of nitrite ion was studied. The method is based on the nitrosation reaction of acridine red with nitrite ion in hydrochloric acid medium. The decolorization of acridine red by the reaction with nitrite was used to spectrophotometric determination at 525 nm. The optimum experimental conditions have been confirmed and 6 mol.L-1 hydrochloric acid is 1.5 mL; 5 x 10(-4) mol.L-1 acridine red is 2.0 mL, the reaction time is 20 min. On the selected conditions, Beer's law is obeyed and the linear range for the determination is 0.025-0.5 microgram.mL-1 NO2-.28 coexistent ions were examined and no serious interference for most of ions was observed. The method has been applied to determine nitrite ion in four water samples with satisfactory results. The relative standard deviation was less than 2.6% for 5 measurements in each water sample. A preliminary relation mechanism is supposed.