Journal cover Journal topic
Atmospheric Measurement Techniques An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 3.668 IF 3.668
  • IF 5-year value: 3.707 IF 5-year
  • CiteScore value: 6.3 CiteScore
  • SNIP value: 1.383 SNIP 1.383
  • IPP value: 3.75 IPP 3.75
  • SJR value: 1.525 SJR 1.525
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 77 Scimago H
    index 77
  • h5-index value: 49 h5-index 49
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

  04 May 2020

04 May 2020

Review status
This preprint is currently under review for the journal AMT.

An inter-laboratory comparison of aerosol in organic ion measurements by Ion Chromatography: implications for aerosol pH estimate

Jingsha Xu1, Shaojie Song2, Roy M. Harrison1, Congbo Song1, Lianfang Wei3, Qiang Zhang4, Yele Sun3, Lu Lei3, Chao Zhang5, Xiaohong Yao5,6, Dihui Chen5, Weijun Li7, Miaomiao Wu7, Hezhong Tian8, Lining Luo8, Shengrui Tong9, Weiran Li9, Junling Wang10, Guoliang Shi11, Yanqi Huangfu11, Yingze Tian11, Baozhu Ge3, Shaoli Su12, Chao Peng12, Yang Chen12, Fumo Yang13, Aleksandra Mihajlidi-Zelić14, Dragana Đorđević14, Stefan J. Swift15, Imogen Andrews15, Jacqueline F. Hamilton15, Ye Sun16, Agung Kramawijaya1, Jinxiu Han1, Supattarachai Saksakulkrai1, Clarissa Baldo1, Siqi Hou1, Feixue Zheng17, Kaspar R. Daellenbach17, Chao Yan17, Yongchun Liu17, Markku Kulmala17, Pingqing Fu4, and Zongbo Shi1 Jingsha Xu et al.
  • 1School of Geography Earth and Environmental Science, University of Birmingham, Birmingham, B152TT, UK
  • 2School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
  • 3State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China
  • 4Institute of Surface-Earth System Science, Tianjin University, Tianjin, 300072, China
  • 5Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Environment and Ecology, Ministry of Education of China, Ocean University of China, Qingdao 266100, China
  • 6Laboratory for Marine Ecology and Environmental Sciences, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China
  • 7Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou, 310027, China
  • 8Center for Atmospheric Environmental Studies, Beijing Normal University, Beijing, 100875, China
  • 9State Key Laboratory of Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
  • 10School of Environment, Tsinghua University, Beijing, 100084, China
  • 11State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, Center for Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China
  • 12Research Center for Atmospheric Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, 26400714, China
  • 13Department of Environmental Science and Engineering, Sichuan University, Chengdu, 610065, China
  • 14Centre of Excellence in Environmental Chemistry and Engineering – ICTM, University of Belgrade 12, Njegoševa (Studentskitrg 14–16), Belgrade, Serbia
  • 15Department of Chemistry, University of York, York, YO10 5DD, UK
  • 16School of Space and Environment, Beihang University, Beijing, 100191, China
  • 17Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China

Abstract. Water soluble inorganic ions such as ammonium, nitrate, and sulfate are major components of fine aerosols in the atmosphere and are widely used in the estimation of aerosol acidity. However, different experimental practices and instrumentation may lead to uncertainties in ion concentrations. Here, an inter-comparison experiment was conducted in 10 different laboratories (labs) to investigate the consistency of inorganic ion concentrations and resultant aerosol acidity estimates using the same set of aerosol filter samples. The results mostly exhibited good agreement for major ions Cl, SO42−, NO3, NH4+ and K+. However, F, Mg2+ and Ca2+ were observed with more variations across the different labs. The Aerosol Chemical Speciation Monitor (ACSM) data of non-refractory SO42−, NO3, NH4+ generally correlated very well with the filter analysis based data in our study, but the absolute concentrations differ by up to 42 %. Cl from the two methods are correlated but the concentration differ by more than 3 times. The analyses of certified reference materials (CRMs) generally showed good recovery of all ions in all the labs, the majority of which ranged between 90 % and 110 %. Better agreements were found for Cl, SO42−, NO3, NH4+ and K+ across the labs after their concentrations were corrected with CRM recoveries; the coefficient of variation (CV) of Cl, SO42−, NO3, NH4+ and K+ decreased 1.7 %, 3.4 %, 3.4 %, 1.2 % and 2.6 %, respectively, after CRM correction. We found that the ratio of anion to cation equivalent concentrations (AE/CE) is not a good indicator for aerosol acidity estimates, as the results in different labs did not agree well with each other. Ion balance (anions – cations) calculated from SO42−, NO3 and NH4+ gave more consistent results, because of their relatively large concentrations and good agreement among different labs. In situ aerosol pH calculated from the ISORROPIA-II thermodynamic equilibrium model with measured ion and ammonia concentrations showed a similar trend and good agreement across the 10 labs. Our results indicate that although there are important uncertainties in aerosol ion concentration measurements, the estimated aerosol pH from the ISORROPIA-II model is more consistent.

Jingsha Xu et al.

Interactive discussion

Status: final response (author comments only)
Status: final response (author comments only)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment

Jingsha Xu et al.

Jingsha Xu et al.


Total article views: 346 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
250 85 11 346 7 8
  • HTML: 250
  • PDF: 85
  • XML: 11
  • Total: 346
  • BibTeX: 7
  • EndNote: 8
Views and downloads (calculated since 04 May 2020)
Cumulative views and downloads (calculated since 04 May 2020)

Viewed (geographical distribution)

Total article views: 302 (including HTML, PDF, and XML) Thereof 302 with geography defined and 0 with unknown origin.
Country # Views %
  • 1



No saved metrics found.


No discussed metrics found.
Latest update: 08 Aug 2020
Publications Copernicus
Short summary
An inter-laboratory comparison exercise was conducted for the first time to examine the difference of water-soluble inorganic ions (WSII) measured by 10 labs using Ion Chromatography and by 2 online Aerosol Chemical Speciation Monitor method. Major ions including SO42−, NO3, NH4+ agreed well in 10 IC labs, and correlated well with ACSM. WSII inter-lab variability strongly affected aerosol acidity results based on ion balance, but aerosol pH computed by ISORROPIA-II were very similar.
An inter-laboratory comparison exercise was conducted for the first time to examine the...