Description: Das Projekt "Analysis of volatile non-methane hydrocarbons in air: improvement and harmonisation of the canister sampling and analysis" wird vom Umweltbundesamt gefördert und von Fraunhofer-Gesellschaft zur Förderung der Angewandten Forschung, Fraunhofer-Institut für Atmosphärische Umweltforschung durchgeführt. Objective: The AMOHA project aimed at improvement of NMHC measurement techniques based on sampling ambient air in stainless steel canisters. The project consisted of RTD and intercomparison parts. In the RTD part each step of the sampling and analysis procedure has been investigated, problem areas have been identified and recommendations for the best measurement practice had to be made. In the intercomparison part the analytical proficiency of up to 15 European laboratories has been tested in four annual intercomparisons of increasing complexity. Work programme: Procedures for cleaning canisters, sampling of ambient air, sample preconditioning, separation of individual NMHC compounds, their identification and quantification, preparation of stable standards and testing of NMHC gas mixtures have been investigated in the RTD part. In the intercomparison part we carried out four NMHC intercomparisons using synthetic 4 component, 30 component, 30 component plus pressurised ambient air test samples in the 1st, 2nd, and 3rd intercomparisons, respectively, and ambient air measurements in the 4th intercomparison. The results of each intercomparison were discussed at a workshop in order to obtain feedback on the measurement problems of the participants and to demonstrate that the problems can be overcome. The improved measurement practice has been described in standard operating procedures (SOPs). General Information: Accurate measurements of non-methane hydrocarbons (NMHCs) in ambient air are one of the major prerequisites to designing measures for the control of ozone precursor emissions and monitoring the efficiency of this control. NMHC measurements in ambient air are difficult because a large number of individual substances (30 and more) have to be identified and quantified at mixing ratios of usually less than 1 ppbv (10-9 volume ratio) in the presence of interfering substances. Previous intercomparisons in Europe and North America showed large differences between laboratories when measuring NMHCs in synthetic test and ambient air samples. Achievements: Currently used electropolished stainless steel canisters proved to be superior for NMHC measurements to silica lined and aluminium canisters, although the latter might offer advantages when other more polar volatile organic compounds are to be measured. Aluminium high-pressure cylinders performed better in terms of NMHC stability for pressurised ambient air sample than stainless steel high-pressure cylinders. Reactions of ozone with NMHCs in the ambient air sample influenced only the most reactive NMHCs (butadiene and isoprene), because of rapid destruction of ozone within the sampling pump and the canister. Several preconditioning procedures (drying and CO2 removal) were successfully tested. ... Prime Contractor: Fraunhofer-Gesellschaft zur Förderung der Angewandten Forschung, Fraunhofer-Institut für Atmosphärische Umweltforschung; Garmisch-Partenkirchen; Germany.
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Aluminiumoxid ? Butadien ? Alken ? Ozon ? Ozonwert ? Tierhaltungsanlage ? Aluminium ? Siliziumdioxid ? Ozonvorläufer ? VOC ? Außenluft ? Isopren ? Gasgemisch ? Kohlendioxid ? Materialprüfung ? Messtechnik ? Methan ? Probenaufbereitung ? Edelstahl ? NMVOC ? EU-Länder ? Volumenmessung ? Ozonschicht ? Stichprobe ? Umweltforschung ? Emission ? Analysegerät ? Reinigungsmittel ? Stoff ? Analyseverfahren ? Amerika ? Europa ? Angewandte Wissenschaft ? Luftprobe ? Probenahme ? Schadstoff ? Laboruntersuchung ? Beste verfügbare Techniken ? Chemische Reaktion ? Workshop ? Standardisierung ? On-Line-Betrieb ? Schadstoffnachweis ? Eignungsfeststellung ?
Region: Bayern
Bounding box: 12.53381° .. 12.53381° x 47.795° .. 47.795°
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 1996-10-01 - 2000-09-30
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