Ricerc@Sapienza

This work is part of an extensive research project aimed at the determination and characterization of bioaerosol with a
multidisciplinary approach. In this context, one of the main objectives of the project has been the development of a
comprehensive analytical method for the determination of different chemical biomarkers of the bioaerosol, by liquid
chromatography coupled with tandem mass spectrometry. The following biomarkers have been considered, and
correlated to specific components of bioaerosol as unambiguous indicators: • ergosterol fungal components •
chlorophylls, phytosterols (stigmasterol and b-sitosterol), -tocoferol vegetable cells and algae • cholesterol animal
cells, vegetable cells and algae. • dipicolinic acid bacterial spores • muramic and meso-2,6-diaminopimelic acid
bacterial cells To verify the method, to find diagnostic ratios and to calculate the appropriate conversion factors, fungal
spores, bacterial cells and spores, and algae of known species, commonly airborne, were analysed. The material was
subjected to freezing and de-freezing cycles, followed by extraction, hydrolysis and purification of the biomarkers. The
chromatographic separation of the bacterial biomarkers was achieved by using a polymeric column, based on
Hydrophilic Liquid Interaction with the electrospray ionization mass spectrometric detection, whereas sterols and
chlorophylls were separated by a reversed phase column, coupled to atmospheric pressure chemical ionization –
tandem mass spectrometer. The optimized method was applied to environmental particulate matter sampled in an
outdoor site. Bacterial and fungal content was compared to the results obtained from the classical direct viable
counting method in the sampled particulate matter