Cavity Ring-Down Spectroscopy Measurements of Ambient NO3 and N2O5

• 作 者: Hao Wu Jian Chen An-wen Liu Shui-ming Hu Jing-song Zhang
• 机 构: Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technol
• 出 处: 化学物理学报（英文版）
• 发表日期: 2020年1期
• 关键词: Cavity ring-down spectroscopy Nitrate radical Dinitrogen pentoxide Field measure

NO3 and N2O5 are important participants in noctal atmospheric chemical processes,and their concentrations are of great significance in the study of the mechanism of noctal atmospheric chemical reactions.A two-channel diode laser based cavity ring-down spectroscopy (CRDS) instrument was developed to monitor the concentrations of NO3 and N2O5 in the atmosphere.The effective absorption length ratio and the total loss coefficient of the instrument were calibrated using laboratory standard samples.The effective absorption cross section of NO3 at 662 nm was derived.A detection sensitivity of 1.1 pptv NO3 in air was obtained at a time resolution of 1 s.N2O5 was converted to NO3 and detected online in the second CRDS channel.The instrument was used to monitor the concentrations of NO3 and N2O5 in the atmosphere of winter in Hefei in real time.By comparing the concentration changes of pollutants such as nitrogen oxides,ozone,PM2.5 in a rapid air cleaning process,the factors affecting the concentrations of NO3 and N2O5 in the atmosphere were discussed.