Aldona Łowińska-Kluge

Microwave-Assisted Extraction Combined with HPLC-MS/MS for Diagnosis of Fungal Contamination in Building Materials

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.

A comprehensive study on the risk of biocorrosion of building materials

The fungal genera are known for their high ability to biodeteriorate construction materials. Weight loss and release of calcium are observed when materials, especially concrete, are exposed to fungi. The paper presents the procedures enabling to assess the risk of biocorrosion of buildings at various stages of its development. The presented results lead to selection of effective analytical methodology for this propose. The study was conducted on materials commonly used as construction materials such as granite, ceramic, concrete and plaster. Surfaces of the tested samples were fouled by three selected fungal genera. Changes in properties of the materials due to interaction of fungi have been studied with the use of ergosterol content measurements, microscopic picturing, bioluminescence imaging, measurements of pH and X-ray spectroscopy analysis. Particular attention was paid to propose an appropriate method of estimating the effect of fungi on the surface of building materials using advanced analytical techniques.