Differentiation of air samples with and without microbial volatile organic compounds by aspiration ion mobility spectrometry and semiconductor sensors

A chemical detector ChemPro100i containing aspiration type ion mobility spectrometry (aspiration IMS), five semiconductor sensors (MOS) and field effect transistor sensor (FET) was used for the detection and monitoring of microbial volatile organic compounds (MVOC). MVOCs were detected from the headspace of glass chambers which contained a specimen of building material in humid conditions. Results regarding particle board as a substrate for mould growth are represented. A specimen kept under sterile conditions was used as a reference. Samples were incubated for 22 days and detector responses as well as air samples introduced into Tenax adsorbent were collected for seven days during the incubation. Air samples were analyzed by thermal desorption gas chromatography mass spectrometry (TD-GC-MS) for identifying the possible MVOCs. MVOC detection was done by comparing the chromatogram peak intensities between the contaminated and the sterile samples. Detector responses were monitored before and after air sampling and data was analyzed by means of multivariate data analysis (MVDA) using SIMCA-P 10.0 software (Umetrics, Umeå, Sweden). Results showed that when incubation proceeded the different samples could be separated by both aspiration IMS combined with sensors and TD-GC-MS and that the results obtained by both methods also had a visible time trend.