The second ACTRIS inter-comparison (2016) for Aerosol Chemical Speciation Monitors (ACSM): Calibration protocols and instrument performance evaluations.
Creators: name: Freney, Evelyn
name: Yunjiang Zhang
name: Croteau, Philip
name: Amodeo, Tanguy
name: Williams, Leah
name: Truong, François
name: Jean-Eudes Petit
name: Sciare, Jean
name: Sarda-Esteve, Roland
name: Bonnaire, Nicolas
name: Arumae, Tarvo
name: Aurela, Minna
name: Bougiatioti, Aikaterini
name: Mihalopoulos, Nikolaos
name: Coz, Esther
name: Artinano, Begoña
name: Crenn, Vincent
name: Elste, Thomas
name: Liine Heikkinen
name: Poulain, Laurent
name: Wiedensohler, Alfred
name: Herrmann, Hartmut
name: Priestman, Max
name: Alastuey, Andres
name: Stavroulas, Iasonas
name: Tobler, Anna
name: Vasilescu, Jeni
name: Zanca, Nicola
name: Canagaratna, Manjula
name: Carbone, Claudio
name: Flentje, Harald
name: Green, David
name: Maasikmets, Marek
name: Luminita Marmureanu
name: Minguillon, Maria Cruz
name: Prevot, Andre S.H.
name: Gros, Valerie
name: Jayne, John
name: Favez, Olivier
Publisher: name: Taylor & Francis
Year: 2019
Subjects: subject: Biochemistry
subject: Space Science
subject: Neuroscience
subject: Biotechnology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: FOS: Chemical sciences
subject: Science Policy
subject: Plant Biology
subject: FOS: Biological sciences
subject: FOS: Biological sciences

description: This work describes results obtained from the 2016 Aerosol Chemical Speciation Monitor (ACSM) intercomparison exercise performed at the Aerosol Chemical Monitor Calibration Centre (ACMCC, France). Fifteen quadrupole ACSMs (Q_ACSM) from the European Research Infrastructure for the observation of Aerosols, Clouds and Trace gases (ACTRIS) network were calibrated using a new procedure that acquires calibration data under the same operating conditions as those used during sampling and hence gets information representative of instrument performance. The new calibration procedure notably resulted in a decrease in the spread of the measured sulphate mass concentrations, improving the reproducibility of inorganic species measurements between ACSMs as well as the consistency with co-located independent instruments. Tested calibration procedures also allowed for the investigation of artefacts in individual instruments, such as the overestimation of <i>m/z</i> 44 from organic aerosol. This effect was quantified by the <i>m/z</i> (mass-to-charge) 44 to nitrate ratio measured during ammonium nitrate calibrations, with values ranging from 0.03 up to 0.26, showing that it can be significant for some instruments. The fragmentation table correction previously proposed to account for this artefact was applied to the measurements acquired during this study. For some instruments (those with high artefacts), this fragmentation table adjustment led to an “overcorrection” of the <i>f44</i> (<i>m/z</i> 44/Org) signal. This correction based on measurements made with pure NH<sub>4</sub>NO<sub>3</sub>, assumes that the magnitude of the artefact is independent of chemical composition. Using data acquired at different NH<sub>4</sub>NO<sub>3</sub> mixing ratios (from solutions of NH<sub>4</sub>NO<sub>3</sub> and (NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub>) we observe that the magnitude of the artefact varies as a function of composition. Here we applied an updated correction, dependent on the ambient NO<sub>3</sub> mass fraction, which resulted in an improved agreement in organic signal among instruments. This work illustrates the benefits of integrating new calibration procedures and artefact corrections, but also highlights the benefits of these intercomparison exercises to continue to improve our knowledge of how these instruments operate, and assist us in interpreting atmospheric chemistry.