A simple and rapid GC/MS method for the simultaneous determination of gaseous metabolites

We modified and tuned a commercial model of a gas chromatography/mass spectrometry (GC/MS) instrument to develop a simple and rapid method for the simultaneous quantification of a variety of gas species. Using the developed method with the newly modified instrument, gas species such as H2, N2, O2, CO, NO, CH4, CO2, and N2O, which are common components of microbial metabolism, were accurately identified based on their retention times and/or mass-to-charge ratios (m/z) in less than 2.5 min. By examining the sensitivities and dynamic ranges for the detection of H2, N2, O2, CH4, CO2, and N2O, it was demonstrated that the method developed in this study was sufficient for accurately monitoring the production and the consumption of these gaseous species during microbial metabolism. The utility of the new method was demonstrated by a denitrification study with Pseudomonas aureofaciens ATCC 13985T. This method will be suitable for a variety of applications requiring the identification of gaseous metabolites in microorganisms, microbial communities, and natural ecosystems.