Volatile organic substances in a forest atmosphere.

Qualitative analyses of volatile organic substances were performed at a site in the Eggegebirge in North Rhine-Westfalia (West Germany) were severe spruce damage has been observed in the last decade. Organics were adsorbed on solid sorbents and analysed by thermodesorption GC/MS. About 230 different substances were found, 209 of which were identified. Predominant substance classes were alkylated aromatics, aliphatics and halogenated solvents. Further frequent species included terpenes, ketones, esters, aldehydes and carboxylic acids. The investigations revealed a predominance of substances of anthropogenic origin.