依文思蓝褪色光度法测定亚硝酸根

Spectrophotometric Determination of Trace Nitrite with Evans Blue

研究亚硝酸根与依文思蓝的褪色反应，建立一个简单、灵敏、选择性高的亚硝酸根的测定方法。采用紫外分光光度法测定不同条件下的吸光度。实验表明，当依文思蓝与NO2反应后发生颜色变化，在615nm波长处发生褪色反应，此波长处，吸光度的变化与溶液中N0f的浓度成正比，其线性范围在0～20μgZ5mL，摩尔吸光系数为ε=1．4×10^4L/（mol·cm），相关系数为0．9995。方法具有良好的稳定性和选择性；建立了测定亚硝酸根的新方法；用于环境水样中微量N0f的测定，结果满意。

Spectrophotometric method was used for the determination of trace nitrite in UV-vis by reaction with evans blue. The linear range for the determination is 0～20 μg/25 mL NO2^-. The molar absorptivity of the method ε is 1.4 × 10T^4 L/（mol·cm）. Most of coexistent ions do not interfere the determination of NO2^-,and the selectivity of the method is good. The method has been applied to the determination of nitrite samples with satisfactory results.