EC Intercomparison of VOC Measurements Between National Reference Laboratories (AQUILA Network)
Between May 2007 and February 2008, cylinders from two mixtures (synthetic and ambient air) circulated amongst 18 AQUILA laboratories to evaluate their performance in the analysis of the 30 volatile organic compounds listed in the directive EC/50/2008.
The concentration for the compared mixtures was of circa 5 and 1 ppb per compound in the synthetic and ambient air mixture, respectively. Laboratories were asked to carry out five independent measurements for each mixture and provide values and associated uncertainties. A full description of the analytical method used by each laboratory and their calculations for the estimation of the
uncertainties was also included in the report.
The results were finally expressed in terms of bias with respect to the reference value and the En number of the measurement. In general, analytical uncertainties were higher for the lower concentration mixture in comparison to the higher one. For the synthetic mixture, half of the laboratories reported overall expanded uncertainties better than 10 %, whilst for the ambient air mixture, the same percentage of laboratories showed only values better than 20 %.
The heaviest hydrocarbons (123, 124 and 135 trimethyl benzene, m,p- xylene, ethyl-benzene and benzene) and those more reactive and lighter (like 1,3 butadiene, isoprene, 1-pentene) were analysed with more difficulty in comparison to the rest of the compounds.
PEREZ BALLESTA Pascual;
2009-01-23
OPOCE
JRC47754
978-92-79-10048-2,
1018-5593,
EUR 23529 EN,
OP LB-NA-23529-EN-C,
https://publications.jrc.ec.europa.eu/repository/handle/JRC47754,
10.2788/11627,
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