Protonated acetone ion chemical ionization time-of-flight mass spectrometry for real-time measurement of atmospheric ammonia

作     者：Fengshuo Dong Hang Li Bing Liu Ruidong Liu Keyong Hou Fengshuo Dong;Hang Li;Bing Liu;Ruidong Liu;Keyong Hou

作者机构：Environment Research InstituteShandong UniversityQingdao 266237China Key Laboratory of Separation Science for Analytical ChemistryDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2022年第34卷第4期

页      面：66-74页

核心收录：

学科分类：07[理学] 070602[理学-大气物理学与大气环境] 0706[理学-大气科学] 0703[理学-化学] 

基　　金：partially supported by the National Special Fund for the Development of Major Research Equipment and Instrument(No.2020YFF01014503) NSF of China(No.21874134) Young Taishan Scholars(No.tsqn201909039) 

主　　题：Ammonia(NH_(3)) Chemical ionization mass spectrometer(CIMS) Vacuum ultraviolet(VUV)lamp Single photon ionization Real-time analysis 

摘      要：Ammonia(NH_(3))is ubiquitous in the atmosphere,it can affect the formation of secondary aerosols and particulate matter,and cause soil eutrophication through ***,the use of radioactive primary reagent ion source and the humidity interference on the sensitivity and stability are the two major issues faced by chemical ionization mass spectrometer(CIMS)in the analysis of atmospheric *** this work,a vacuum ultraviolet(VUV)Kr lamp was used to replace the radioactive source,and acetone was ionized under atmospheric pressure to obtain protonated acetone reagent ions to ionize *** ionization source is designed as a separated three-zone structure,and even 90 vol.%high-humidity samples can still be directly analyzed with a sensitivity of sub-ppbv.A signal normalization processing method was designed,and with this new method,the quantitative relative standard deviation(RSD)of the instrument was decreased from 17.5%to9.1%,and the coefficient of determination was increased from 0.8340 to *** humidity correction parameters of the instrument were calculated from different humidity,and the ammonia concentrations obtained under different humidity were converted to its concentration under zero humidity condition with these correction *** analytical time for a single sample is only 60 sec,and the limit of detection(LOD)was 8.59 pptv(signalto-noise ratio S/N=3).The ambient measurement made in Qingdao,China,in January 2021 with this newly designed CIMS,showed that the concentration of ammonia ranged from 1 to 130 ppbv.