Measurement of tropospheric HO_(2) radical using fluorescence assay by gas expansion with low interferences  

作　　者：Yihui Wang Renzhi Hu Pinhua Xie Hao Chen Fengyang Wang Xiaoyan Liu JianGuo Liu Wenqing Liu 

机构地区：[1]School of Enuironmental Science and Optoelectronic Technology,University of Science and Technology of China,Hefei 230026,Anhui,China [2]Key Laboratory of Environmental Optics and Technology,Anhui Institute of optics and Fine Mechanics,ChineseAcademy of Sciences,Hefei 230031,Anhui,China [3]CAS Center for Excellence in Regional Atmospheric Enuvironment,Institute of Urban Enuironment,ChineseAcademy of Sciences,Xiamen 361000,Fujian,China [4]University of Chinese Academy of Sciences,Beijing 100049,Beijing,China [5]College of Mechanical Engineering,Suzhou University of Science and Technology,Suzhou 215009,jiangsu,China [6]College of Pharmacy,Anhui Medical University,Hefei 230032,Anhui,China

出　　处：《Journal of Environmental Sciences》2021年第1期40-50,共11页环境科学学报（英文版）

基　　金：The National Key Research and Development Program of China(Nos.2017YFC0209401,2017YFC0209403);the National Natural Science Foundation of China(Nos.61905003,61805257,91644107,and 61575206);the Natural Science Foundation of Anhui Province(No.2008085J20);the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB05040200)。

摘　　要：An instrument to detect atmospheric HO_(2) radicals using fluorescence assay by gas expansion(FAGE)technique has been developed.HO_(2) is measured by reaction with NO to form OH and subsequent detection of OH by laser-induced fluorescence at low pressure.The system performance has been improved by optimizing the expansion distance and pressure,the influence factors of HO_(2) conversion efficiency are also studied.The interferences of RO_(2) radicals were investigated by determining the conversion efficiency of RO_(2) to OH during the measurement of HO_(2).The dependence of the conversion of HO_(2) on NO concentration was investigated,and low HO_(2) conversion efficiency was selected to realize the ambient HO_(2) measurement,where the conversion efficiency of RO_(2) derived by propane,ethene,isoprene and methanol to OH has been reduced to less than 6%in the atmosphere.Furthermore,no significant interferences from PM_(2.5) and NO were found in the ambient HO_(2) measurement.The detection limits for HO_(2)(S/N=2)are estimated to 4.8×10^5 cm^-3 and 1.1×10^6 cm^-3(ρHO_(2)=20%)under night and noon conditions,with 60 sec signal integration time.The instrument was successfully deployed during STORM-2018 field campaign at Shenzhen graduate school of Peking University.The concentration of atmospheric HOx radical and the good correlation of OH with j(O1D)was obtained here.The diurnal variation of HOx concentration shows that the OH maximum concentration of those days is about 5.3×10^6 cm^-3 appearing around 12:00,while the HO_(2) maximum concentration is about 4.2×10^8 cm^-3 appearing around 13:30.

关 键 词：HO_(2) radical FAGE INTERFERENCE Environmental measurement 

分 类 号：X831[环境科学与工程—环境工程]