title: Chemical characteristics of size-resolved aerosols in winter in Beijing.
abstract: Size-resolved aerosols were continuously collected by a Nano Sampler for 13 days at an urban site in Beijing during winter 2012 to measure the chemical composition of ambient aerosol particles. Data collected by the Nano Sampler and an ACSM (Aerodyne Aerosol Chemical Speciation Monitor) were compared. Between the data sets, similar trends and strong correlations were observed, demonstrating the validity of the Nano Sampler. PM₁₀ and PM₂.₅ concentrations during the measurement were 150.5 ± 96.0 μg/m³ (mean ± standard variation) and 106.9 ± 71.6 μg/m³, respectively. The PM₂.₅/PM₁₀ ratio was 0.70 ± 0.10, indicating that PM₂.₅ dominated PM₁₀. The aerosol size distributions showed that three size bins of 0.5-1, 1-2.5 and 2.5-10 μm contributed 21.8%, 23.3% and 26.0% to the total mass concentration (TMC), respectively. OM (organic matter) and SIA (secondary ionic aerosol, mainly SO₄(2-), NO₃(-) and NH₄(+)) were major components of PM₂.₅. Secondary compounds (SIA and secondary organic carbon) accounted for half of TMC (about 49.8%) in PM₂.₅, and suggested that secondary aerosols significantly contributed to the serious particulate matter pollution observed in winter. Coal burning, biomass combustion, vehicle emissions and SIA were found to be the main sources of PM₂.₅. Mass concentrations of water-soluble ions and undetected materials, as well as their fractions in TMC, strikingly increased with deteriorating particle pollution conditions, while OM and EC (elemental carbon) exhibited different variations, with mass concentrations slightly increasing but fractions in TMC decreasing.
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China; College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
authors.forename: Kang
authors.initials: K
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Qu
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Han
authors.affiliation: Environmental Science Center, University of Augsburg, Augsburg 86159, Germany.
authors.forename: Jianwei
authors.initials: J
authors.lastname: Gu
authors.affiliation: School of Foreign Languages, China University of Political Science and Law, Beijing 100088, China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
authors.forename: Yele
authors.initials: Y
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Jiang
authors.affiliation: School of Chemistry, Beijing Normal University, Beijing 100875, China.
authors.forename: Ziqi
authors.initials: Z
authors.lastname: Gao
authors.affiliation: College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
authors.forename: Min
authors.initials: M
authors.lastname: Hu
authors.affiliation: College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
authors.forename: Yuanhang
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
authors.forename: Keding
authors.initials: K
authors.lastname: Lu
authors.affiliation: Multiphase Chemistry Department, Max Planck Institute for Chemistry, Mainz 55128, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Nordmann
authors.affiliation: College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
authors.forename: Yafang
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: Laboratory of Atmospheric Environment and Pollution Control Engineering, Graduate School of Natural Science & Technology, Kanazawa University, Kanazawa 9201167, Japan.
authors.forename: Li
authors.initials: L
authors.lastname: Hou
authors.affiliation: Laboratory of Atmospheric Environment and Pollution Control Engineering, Graduate School of Natural Science & Technology, Kanazawa University, Kanazawa 9201167, Japan.
authors.forename: Hui
authors.initials: H
authors.lastname: Ge
authors.affiliation: Laboratory of Atmospheric Environment and Pollution Control Engineering, Graduate School of Natural Science & Technology, Kanazawa University, Kanazawa 9201167, Japan.
authors.forename: Masami
authors.initials: M
authors.lastname: Furuuchi
authors.affiliation: Laboratory of Atmospheric Environment and Pollution Control Engineering, Graduate School of Natural Science & Technology, Kanazawa University, Kanazawa 9201167, Japan.
authors.forename: Mitsuhiko
authors.initials: M
authors.lastname: Hata
authors.affiliation: State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, China. Electronic address: liuxingang@bnu.edu.cn.
authors.forename: Xingang
authors.initials: X
authors.lastname: Liu
mesh_terms: D000336:Aerosols; D000393:Air Pollutants / Q000737:chemistry*; D002681:China; D052638:Particulate Matter / Q000737:chemistry*; D012621:Seasons; D013997:Time Factors
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D052638:Particulate Matter
keywords: Aerosol; Beijing; Chemical characteristics; Size distribution