Profiling Specific Volatile Organic Compounds for Mold Detection and Species Identification

Abstract

Mold is found in most indoor environments and is of great concern due to adverse health effects and infrastructure damage it can cause. One key aspect of this growing problem is early detection and localization of mold contamination so appropriate measures can be implemented. In this study, a combination of solid-phase microextraction (SPME), semiquantitative gas chromatography–mass spectroscopy (GC-MS) analysis, and principal component analysis (PCA) of 14 select microbial volatile organic compounds (MVOCs) was used to determine if volatile organic profiling could be used to differentiate between molds grown on various building materials. Briefly, SPME fibers with PDMS/DVB coatings were employed to collect and generate volatile organic profiles of target MVOCs emitted by Aspergillus versicolor and Penicillium chrysogenum when grown on two common building materials. The volatile compound extraction and identification method revealed that P. chrysogenum grown on gypsum and A. versicolor grown on pine produced unique MVOC profiles from one another, which indicated species and substrate differentiation could be made based on the volatile organic profiles. Additionally, the production of dimethyl disulfide (DMDS) and geosmin was found to be specific to P. chrysogenum and A. versicolor, respectively, and therefore could serve as potential biomarkers for screening for the presence of each species. This study suggests profiling select MVOCs is viable for detecting specific hazardous molds when the substrate is known and a streamlined workflow for indoor mold monitoring: initial broad-spectrum GC-MS screening for fungal presence → selected MVOC profiling for species identification → molecular verification of hazardous species.