Determination of Nitrogen Oxides with Rhodamine B by Fluorescence Quenching Method

NO2 can be transformed into nitrite by the absorption of Rhodamine B solution, which will make fluorescence quenching of Rhodamine B in acidic medium. According to this mechanism, a new method for detecting nitrogen oxides in the air is developed by a fluorescence spectrophotometry. The influence of environmental media and interfering substances in the fluorescence intensity of system was studied. Under the optimal experimental conditions, the decrease of fluorescence intensity varies linearly with the concentration of NO2- over the range of 0.009 ∼ 0.500 μg/ml with a correlation coefficient of 0.9992. The method is simple and has a lower limit of detection than the common methods. It can be a referee for the environmental evaluation.