Methodological issues in GC-MS determination of particle-bound PAHs in time resolved wood burning emission samples

Abstract

PAHs are products of incomplete combustion. One of their major sources are residential and commercial heating. To reduce emissions a detailed understanding of the formation of PAHs during the combustion process is necessary. In this study the emissions from small scale heating devices typical for the Austrian Market measured with a 5 min time resolution are looked at to investigate the influence of fuel, stove and combustion phase on the particulate PAH emission. The most dominant feature for all combustions is the increase of concentrations after the reload of the fuel. This feature is independent of fuel and stove. After the reload the concentration is generally constantly decreasing for log wood but for softwood briquettes a small peak in the end is visible. In general, the change of emission during the combustion is mainly influenced by the combustion conditions and not by fuel or stove type. The stove type and the fuel have effects on the total emissions. Looking at beech as fuel, stove 2 with an automatic primary and secondary air supply regulation has lower emissions than stove 1. When softwood briquettes are used the emissions are the lowest. The trend over time for PM10 and OC is similar, but differs from VOC and EC. Additionally, some methodological issues like the influence of the solvent on the extractability or the long-term stability of deep frozen filters related to the measurement of particulate PAHs on quartz fibre filters using an ultrasonic extraction and GC-MS analysis are investigated.