Study of FTIR Analysis Method for Low Concentration Nitric Oxide Standard Gas

With the continuous tightening of environmental protection policies and increasing public awareness of environmental protection, ultra-low emission monitoring of air pollutant will become an inevitable trend in the development of various industries. Therefore, it is urgent to study the method to accurately measure the low concentration of air pollutants. Fourier Transform Infrared Spectroscopy (FTIR) is a popular technique today due to its unique combination of sensitivity, flexibility, robustness and specificity. It is capable of handling solid, liquid and gaseous analytes and has become one of the most widely used analytical instrumentation techniques in science and environmental monitoring. In this paper, A method for analyzing low concentration nitric oxide standard gas was proposed by Fourier transform infrared spectroscopy, and the characteristic infrared absorption wavelength was selected as the quantification region according to the response intensity of nitric oxide infrared absorption value. 51.6μmol/mol nitric oxide standard gas was diluted into different concentrations by the dynamic dilution method, and the detection limit, linear range of the standard curve, and linearity and precision were investigated. The results showed that the FTIR response values of nitric oxide in the range of (10.320～51.6) μmol/mol were linear with the theoretical values, the R² was 0.9999, and the detection limit was about 0.1 μmol/mol, which was of good precision, and it provided a technical reference for carrying out the development and application of the nitric oxide standard gas.