Improving odour management and abatement performance using Olfactory GC-MS

The measurement of odorous emissions is usually assessed either as odour concentrations (OC) by dilution olfactometry or by the chemical analysis of the odorous compounds such as hydrogen sulphide or the separation of complex gas mixture using analytical instrumentation such as gas chromatography. These techniques either provide information on the perceived effect of the emission (olfactory) or characterise the odours in terms of their chemical composition (analytical) but provide limited information on the relationship between odour impact and the chemical composition. The integration of chemical and olfactory techniques using olfactory-gas chromatography allows for the correlation of chemical and sensory measurements via the coupling of an olfactory port to a GC. The incorporation of mass spectrometry (GC-MS-O) enables individual odorants to be separated, identified and characterised according to their intensity and character. GC-MS-O analysis of emissions from poultry sheds has shown that samples vary in terms of their chemical compositions (i.e. different odorants profiles) as well as the different intensities measured and demonstrates the potential benefits that GC-MS-O analysis can offer in identifying key chemical markers for odour management in terms of odorant removal (i.e. receptor impact) and abatement loading due to chemical saturation.