Determination of microbial volatile organic compounds (MVOCs) by passive sampling onto charcoal sorbents

Passive sampling combined with GC–MS was applied for the detection of microbial volatile organic compounds (MVOCs) emitted by mould cultures. The fungi species Penicillium expansum, Penicillium chrysogenum, Penicillium brevicompactum, Aspergillus fumigatus, Aspergillus versicolor, Aspergillus niger, and Cladosporium cladosporoides were cultivated on dichloran glycerol agar. The emitted volatiles were collected by charcoal-based passive diffusion monitors during the first four weeks of growth. Several alcohols, mainly 2-methyl-1-propanol and 3-methyl-1-butanol, alkenes, ketones, ethers and esters could be identified and quantified after external calibration. Species-specific compounds like 1,3-dimethoxybenzene for A. versicolor could be proposed. Associations between the concentrations of some of the identified MVOCs (e.g. methylfurans and dimethyldisulfide) and indoor mould exposure in dwellings were found in a field study comprising more than 500 dwellings in Leipzig/Germany. It could be concluded that passive sampling onto charcoal adsorbents for the determination of MVOCs is particularly suitable in epidemiological studies with a high number of participants.