Evaluation of the laboratory comparison exercise for SO2, CO, O3, NO and NO2 11th-14th June 2012 Ispra : EC harmonization program for air quality measurements

From the 11th to the 14th of June 2012 in Ispra (IT), six Laboratories of AQUILA (Network of European Air Quality Reference Laboratories) met for a laboratory comparison exercise to evaluate their proficiency in the analysis of inorganic gaseous pollutants covered by European Directive about air quality (SO2, CO, NO, NO2 and O3). The proficiency evaluation, where each participant's bias was compared to two criteria, provides information on the current situation and capabilities to the European Commission and can be used by participants in their quality control system. On the basis of criteria imposed by the European Commission, 92.2% of the results reported by AQUILA laboratories were good both in terms of measured values and reported uncertainties. Another 7.8% of the results had good measured values, but the reported uncertainties were either too high (0.5%) or too small (7.3%). Comparability of results among AQUILA participants at the highest concentration level, excluding outliers, is acceptable in SO2, CO, O3 and NO measurements while NO2 measurement methods showed less satisfactory results.