摘要
本文研究了亚硝酸根与中性红显色反应的条件。在0.09～0.4mol/L HCl介质中,亚硝酸根与中性红生成紫蓝色化合物,其最大吸收峰位于535nm处,反应灵敏(∑_(645)nm=7.40×10~3和9.81×10~3L·mol^(-1)·cm^(-1),选择性好。亚硝酸根含量在0～5μg/25ml及5～25μg/25ml范围内遵守比尔定律。本法曾用于水、土壤及蔬菜中微量亚硝酸根的测定获得满意的结果。
A new spectrophotometric method has been developed for the determination of microamounts of NO_2^- based on the color reaction between NO_2^- and neutral red. In 0.09~0.4mol/L HCl medium, NO_2^- reacts with neutral red to form a violet-blue compound having an absorption maximum at 535 nm. A working wavelength of 645 nm was used for the measurement of absorbances. Beer's law was obeyed for 0~5 and 5~25 μg NO_2^-/25 ml with molar absorptivi-ties of 7.4×l03 L·mol-1 ·cm-1 and 9.51 ×103 L·mol-1 ·cm-1, respectively. The Sandell's sensitivity was 0.0062μg/cm2 and 0. 0053μg/cm2, respectively (an absorbance of 0.001 unit).The interferences of 58 foreign ion were examined and it was found that only Fe ( CN ) 64- , S2- , SO32- and S2O32- interfered with the determination of 10 μg of NO_2^-. The method is simple, rapid, highly selective and accurate. The proposed method has been applied to the determination of microamounts of NO_2^- in waters, soils and vegetables and the results obtained are satisfactory.
出处
《蚌埠医学院学报》
CAS
1992年第3期155-159,共5页
Journal of Bengbu Medical College
关键词
中性红
亚硝酸根
分光光度法
neutral red
nitrite
spectrophotometric determination
waters
soils
vegetables
