Ergosterol was used as indicator of fungal contamination to assess mould presence on the building materials. Microwave-assisted saponification followed by pentane extraction was used in the sample preparation step. Samples of brick, plaster, concrete and granite were analyzed by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Ergosterol concentrations in laboratory infected samples ranged from 6 to 16 ng g-1, while in samples of naturally occurring materials ranged from 66 to 3020 ng g-1. Limits of detection and of quantitation were 1.7 and 5.5 ng g-1, respectively. Recovery and matrix effect were tested using samples spiked at 100 ng g-1. Mean recovery and mean matrix effect were 65.9 and 111.6%, respectively. Microscopic observations and bioluminescence measurements were carried out for the infected samples to make additional confirmation of fungi presence. The ergosterol concentration determined by HPLC-MS/MS in building materials proved to be a suitable indicator to estimate fungal contamination. The developed method was considerably faster for this aim than bioluminescence measurements and traditionally used culture methods.
ergosterol, building material; microwave extraction; bioluminescence imaging
