title: In situ monitoring of atmospheric nitrous acid based on multi-pumping flow system and liquid waveguide capillary cell.
abstract: In the last four decades, various techniques including spectroscopic, wet chemical and mass spectrometric methods, have been developed and applied for the detection of ambient nitrous acid (HONO). We developed a HONO detection system based on long path photometry which consists of three independent modules i.e., sampling module, fluid propulsion module and detection module. In the propulsion module, solenoid pumps are applied. With solenoid pumps the pulsed flow can be computer controlled both in terms of pump stroke volume and pulse frequency, which enables the attainment of a very stable flow rate. In the detection module, a customized Liquid Waveguide Capillary Cell (LWCC) is used. The customized LWCC pre-sets the optical fiber in-coupling with the liquid wave guide, providing the option of fast startup and easy maintenance of the absorption photometry. In summer 2014, our system was deployed in a comprehensive campaign at a rural site in the North China Plain. More than one month of high quality HONO data spanning from the limit of detection to 5ppb were collected. Intercomparison of our system with another established system from Forschungszentrum Juelich is presented and discussed. In conclusion, our instrument achieved a detection limit of 10pptV within 2min and a measurement uncertainty of 7%, which is well suited for investigation of the HONO budget from urban to rural conditions in China.
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China. Electronic address: y.h.liu@pku.edu.cn.
authors.forename: Yuhan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China. Electronic address: k.lu@pku.edu.cn.
authors.forename: Keding
authors.initials: K
authors.lastname: Lu
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
authors.forename: Huabin
authors.initials: H
authors.lastname: Dong
authors.affiliation: Institute of Energy and Climate Research: Troposphere (IEK-8), Forschungszentrum Juelich GmbH, Juelich, Germany.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Cheng
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Zou
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
authors.forename: Yusheng
authors.initials: Y
authors.lastname: Wu
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China.
authors.forename: Xingang
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China. Electronic address: yhzhang@pku.edu.cn.
authors.forename: Yuanhang
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D001272:Atmosphere / Q000737:chemistry*; D002681:China; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods*; D057230:Limit of Detection; D009608:Nitrous Acid / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D009608:Nitrous Acid
keywords: Atmospheric chemistry; Field campaign; HONO; Photometry