Published in

European Geosciences Union, Atmospheric Measurement Techniques Discussions, 7(8), p. 7239-7302

DOI: 10.5194/amtd-8-7239-2015

Links

Tools

Export citation

Search in Google Scholar

ACTRIS ACSM intercomparison – Part I: Reproducibility of concentration and fragment results from 13 individual Quadrupole Aerosol Chemical Speciation Monitors (Q-ACSM) and consistency with Time-of-Flight ACSM (ToF-ACSM), High Resolution ToF Aerosol Mass Spectrometer (HR-ToF-AMS) and other co-located instruments

This paper is made freely available by the publisher.
This paper is made freely available by the publisher.

Full text: Download

Green circle
Preprint: archiving allowed
Green circle
Postprint: archiving allowed
Green circle
Published version: archiving allowed
Data provided by SHERPA/RoMEO

Abstract

As part of the European ACTRIS project, the first large Quadrupole Aerosol Chemical Speciation Monitor (Q-ACSM) intercomparison study was conducted in the region of Paris for three weeks during the late fall–early winter period (November–December 2013). The first week was dedicated to tuning and calibration of each instrument whereas the second and third were dedicated to side-by-side comparison in ambient conditions with co-located instruments providing independent information on submicron aerosol optical, physical and chemical properties. Near real-time measurements of the major chemical species (organic matter, sulfate, nitrate, ammonium and chloride) in the non-refractory submicron aerosols (NR-PM 1 ) were obtained here from 13 Q-ACSM. The results show that these instruments can produce highly comparable and robust measurements of the NR-PM 1 total mass and its major components. Taking the median of the 13 Q-ACSM as a reference for this study, strong correlations ( r 2 > 0.9) were observed systematically for each individual ACSM across all chemical families except for chloride for which three ACSMs showing weak correlations partly due to the very low concentrations during the study. Reproducibility expanded uncertainties of Q-ACSM concentration measurements were determined using appropriate methodologies defined by the International Standard Organization (ISO 17025) and were found to be of 9, 15, 19, 28 and 36 % for NR-PM 1 , nitrate, organic matter, sulfate and ammonium respectively. However, discrepancies were observed in the relative concentrations of the constituent mass fragments for each chemical component. In particular, significant differences were observed for the organic fragment at mass-to-charge ratio 44, which is a key parameter describing the oxidation state of organic aerosol. Following this first major intercomparison exercise of a large number of ACSMs, detailed intercomparison results are presented as well as a discussion of some recommendations about best calibration practices, standardized data processing and data treatment.