PT OC&EC-2026-01

The ACTRIS (Aerosol, Clouds and Trace Gases Research Infrastructure) Centre for Aerosol In-Situ measurements ECAC (European Centre for Aerosol Calibration) completed, in April 2026, the annual inter-laboratory exercise (ILC) for the measurement of Total, Elemental and Organic Carbon (TC, EC, and OC) in particulate matter collected on filters. This exercise was conducted by the European Reference Laboratory for Air Pollution (ERLAP) of the European Commission-Joint Research Centre. The overall scope of this ILC was to determine the comparability and the uncertainty of the TC, OC and EC atmospheric concentration data produced across Europe. This ILC scheme was based on ambient PM2.5 aerosol samples collected on quartz fibre filters at a regional background site in Ispra, Italy. The primary goal was to assess participants’ performance in determining the TC loading and the EC/TC ratio in order to evaluate the accuracy of the instrument response throughout the analytical chain and the optical correction for charring, respectively. Thirty-nine laboratories, with forty-one analyzers in total, participated in this exercise, all - except one - running EUSAAR_2 / Transmittance as their usual thermal-optical protocol with their usual analytical instrument. Participants’ performance was determined in terms of z-scores, a measure of the participants’ bias compared to an assigned value, associated with its standard deviation. Nine outliers and eleven stragglers, and five outliers and twenty-seven stragglers were identified for TC mass loadings and EC/TC ratios, respectively.

CAVALLI Fabrizia;  PUTAUD Jean-Philippe; 

2026-09-30

Publications Office of the European Union

JRC147719

978-92-68-42721-7 (online),   

1831-9424 (online),   

EUR 40828,    OP KJ-01-26-359-EN-N (online),   

https://publications.jrc.ec.europa.eu/repository/handle/JRC147719,   

10.2760/3266552 (online),