Quantitative Determination of Gaseous Alkanes Adsorbed on Filter Paper During PM2.5 Sampling

Atmospheric gaseous alkanes adsorbed onto filter paper during sampling of particulate matter with a diameter less than 2.5 μm (PM2.5) were quantitatively evaluated. Air samples were collected using a high-volume air sampler equipped with a PM2.5 impactor. For the determination of gaseous alkanes adsorbed onto the filter paper, two filter papers were introduced into a air sampler. The PM and gaseous compounds were collected on the upstream filter. Part of the gaseous compounds passed through the upstream filter and were also adsorbed onto the downstream filter. The adsorbed alkanes were eluted using ultrasonication with dichloromethane, and subsequently determined using gas chromatography-mass spectrometry. In this study, the gaseous n-alkanes C13-C30 were determined from the downstream filter, and the adsorption profiles of these gaseous alkanes varied with air sampling volumes. The adsorption and evaporation profiles of the alkanes were also investigated using deuterium alkanes.