Abstract

GAW target compounds the results show that the DQOs for repeatability are met in most cases. However for the deviation from the WCC-VOC reference values the picture is different. For some VOCs the concentrations differed significantly among the different laboratories. In terms of both uncertainty... Show moreGAW target compounds the results show that the DQOs for repeatability are met in most cases. However for the deviation from the WCC-VOC reference values the picture is different. For some VOCs the concentrations differed significantly among the different laboratories. In terms of both uncertainty and repeatability a significant number of atmospherically relevant VOCs (e.g. propane, propylene, isoprene, and benzene) are properly determined by most labs. However, difficulties occur with other important VOCs (e.g. acetylene, i-pentane, toluene). From this subset of VOC results it appears imperative to strengthen harmonization procedures particular with regard to real air samplings. These processes have been initiated and include more frequent intercomparisons also covering ambient air samples, individual performance audits, and a future networkwide calibration standard. Show less