Dong Y, Lu C
Department of Chemistry, Huaibei Coal Teachers College, Huaibei 235000, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2001 Oct;21(5):710-2.
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.
研究了一种测定亚硝酸根离子的新分光光度法。该方法基于吖啶红与亚硝酸根离子在盐酸介质中的亚硝化反应。利用吖啶红与亚硝酸反应的褪色在525nm处进行分光光度测定。确定了最佳实验条件：6mol·L⁻¹盐酸1.5mL；5×10⁻⁴mol·L⁻¹吖啶红2.0mL，反应时间20min。在选定条件下，符合比尔定律，测定的线性范围为0.025 - 0.5μg·mL⁻¹NO₂⁻。考察了28种共存离子，多数离子无严重干扰。该方法已用于测定四个水样中的亚硝酸根离子，结果令人满意。每个水样进行5次测定，相对标准偏差小于2.6%。推测了初步的反应机理。
