München 2004 – scientific programme
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UP: Umweltphysik
UP 2: Atmosph
äre und Klima I
UP 2.3: Fachvortrag
Monday, March 22, 2004, 14:45–15:00, HS 118
The ECHO project intercomparison of different systems for organic trace gas measurements — •Christoph Holzke1 and intercomparison team ECHO2 — 1Institut fuer Chemie und Dynamik der Geosphaere, Institut II: Troposphaere (ICG-II), Forschungszentrum Juelich, D-52425 Juelich, Germany — 2different paticipating institutes
Despite their importance for atmospheric chemistry, there is still a large uncertainty about the exact amount of biogenic VOC (Volatile Organic Compound) emissions and their contribution to tropospheric chemistry. The analysis of VOCs in ambient air is a difficult task because of the methodical complexity. This is one reason for the uncertainties in the quantification of these emissions. In this paper we present the results of two intercalibration experiments that were conducted as part of the quality assurance within the ECHO project (Emission and Chemical Transformation of Biogenic Volatile Organic Compounds). Since many biogenic VOCs are not stable in gas cylinders as used for round robin tests, the intercalibration experiments were done on site in the laboratory. We set up a permeation source to produce a constant flow of a complex mixture of VOCs with mixing ratios in the range of ppt to ppb. The experiments focussed on the intercomparison of the quantification of specific biogenic VOCs and some of their degradation products. The intercomparison covered the following analytical systems: one on-line GC/FID, two on-line GC/MS, three off-line GC/MS, one off-line GC/FID/MS (off-line sampling on adsorption tubes), and four PTR-MS. The time resolution of the different systems was in the range of 40 minutes to 10 seconds.