Detection of atmospheric gaseous amines and amides by a high-resolution time-of-flight chemical ionization mass spectrometer with protonated ethanol reagent ions
Lei Yao1,Ming-Yi Wang1,a,Xin-Ke Wang1,Yi-Jun Liu1,b,Hang-Fei Chen1,Jun Zheng2,Wei Nie3,4,Ai-Jun Ding3,4,Fu-Hai Geng5,Dong-Fang Wang6,Jian-Min Chen1,Douglas R. Worsnop7,and Lin Wang1,4Lei Yao et al.Lei Yao1,Ming-Yi Wang1,a,Xin-Ke Wang1,Yi-Jun Liu1,b,Hang-Fei Chen1,Jun Zheng2,Wei Nie3,4,Ai-Jun Ding3,4,Fu-Hai Geng5,Dong-Fang Wang6,Jian-Min Chen1,Douglas R. Worsnop7,and Lin Wang1,4
1Shanghai Key Laboratory of Atmospheric Particle Pollution
and Prevention (LAP), Department of Environmental Science
& Engineering, Fudan University, Shanghai 200433, China
2Jiangsu Key Laboratory of Atmospheric Environment Monitoring
and Pollution Control, Nanjing University of Information Science &
Technology, Nanjing 210044, China
3Joint International Research Laboratory of Atmospheric and
Earth System Sciences, School of Atmospheric Science, Nanjing
University, Nanjing 210023, China
4Collaborative Innovation Center of Climate Change, Nanjing 210023, China
5Shanghai Meteorology Bureau, Shanghai 200135, China
6Shanghai Environmental Monitoring Center, Shanghai 200030,
China
7Aerodyne Research, Billerica, MA 01821, USA
anow at: Center for Atmospheric Particle Studies, Carnegie
Mellon University, Pittsburgh, PA 15213, USA
bnow at: Pratt School of Engineering, Duke University, Durham,
NC 27705, USA
1Shanghai Key Laboratory of Atmospheric Particle Pollution
and Prevention (LAP), Department of Environmental Science
& Engineering, Fudan University, Shanghai 200433, China
2Jiangsu Key Laboratory of Atmospheric Environment Monitoring
and Pollution Control, Nanjing University of Information Science &
Technology, Nanjing 210044, China
3Joint International Research Laboratory of Atmospheric and
Earth System Sciences, School of Atmospheric Science, Nanjing
University, Nanjing 210023, China
4Collaborative Innovation Center of Climate Change, Nanjing 210023, China
5Shanghai Meteorology Bureau, Shanghai 200135, China
6Shanghai Environmental Monitoring Center, Shanghai 200030,
China
7Aerodyne Research, Billerica, MA 01821, USA
anow at: Center for Atmospheric Particle Studies, Carnegie
Mellon University, Pittsburgh, PA 15213, USA
bnow at: Pratt School of Engineering, Duke University, Durham,
NC 27705, USA
Received: 07 Jun 2016 – Discussion started: 22 Jun 2016 – Revised: 15 Oct 2016 – Accepted: 03 Nov 2016 – Published: 23 Nov 2016
Abstract. Amines and amides are important atmospheric organic-nitrogen compounds but high time resolution, highly sensitive, and simultaneous ambient measurements of these species are rather sparse. Here, we present the development of a high-resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS) method, utilizing protonated ethanol as reagent ions to simultaneously detect atmospheric gaseous amines (C1 to C6) and amides (C1 to C6). This method possesses sensitivities of 5.6–19.4 Hz pptv−1 for amines and 3.8–38.0 Hz pptv−1 for amides under total reagent ion signals of ∼ 0.32 MHz. Meanwhile, the detection limits were 0.10–0.50 pptv for amines and 0.29–1.95 pptv for amides at 3σ of the background signal for a 1 min integration time. Controlled characterization in the laboratory indicates that relative humidity has significant influences on the detection of amines and amides, whereas the presence of organics has no obvious effects. Ambient measurements of amines and amides utilizing this method were conducted from 25 July to 25 August 2015 in urban Shanghai, China. While the concentrations of amines ranged from a few parts per trillion by volume to hundreds of parts per trillion by volume, concentrations of amides varied from tens of parts per trillion by volume to a few parts per billion by volume. Among the C1- to C6-amines, the C2-amines were the dominant species with concentrations up to 130 pptv. For amides, the C3-amides (up to 8.7 ppb) were the most abundant species. The diurnal and backward trajectory analysis profiles of amides suggest that in addition to the secondary formation of amides in the atmosphere, industrial emissions could be important sources of amides in urban Shanghai. During the campaign, photo-oxidation of amines and amides might be a main loss pathway for them in daytime, and wet deposition was also an important sink.
We present the development of a high-resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS) method, utilizing protonated ethanol as reagent ions to simultaneously detect atmospheric gaseous amines (C1 to C6) and amides (C1 to C6). Deployment of this ethanol HR-ToF-CIMS has been demonstrated in a field campaign in urban Shanghai, China, detecting amines (from a few pptv to hundreds of pptv) and amides (from tens of pptv to a few ppbv).
We present the development of a high-resolution time-of-flight chemical ionization mass...
