Sampling, characterisation and analysis of malodours

Abstract The identification of components, which are responsible for the malodour of confinement swine buildings, was performed with manure as the starting product. This is the principal source of the malodours; less important sources are feed, the bodies of the animals and straw For the isolation of the volatile components from the manure two methods available: • - aeration of the manure with N 2 . • extraction of the manure with organic solvents. The second method was used in this study. The extract of the manure was analysed by gas chromatography. The eluted components were smelled by a panel. Components that were — to the judgement of the panel — of importance for the overall odour of the manure, have been identified by mass spectrometry using a GC-MS-computer combination. The following components were identified: indole, skatole, phenol, p -cresol and the aliphatic carboxylic acids C 2 –C 5 . After comparative measurements of the stench components in the ventilation air of 17 swine buildings it was evident that their proportion was constant within reasonable limits. Another comparative investigation was carried out at 20 confinement swine buildings. The concentration of the stench components was determined by gas chromatography and the intensity of the odour of the ventilation air was measured by a panel of 16 persons. Investigation of the stench components of poultry houses has started in the same way as the confinement swine buildings. The volatiles of the manure are to a great extent similar to those of pig manure. The ventilation air also contains the same components in the same proportion, but in a lower concentration.