Not all historic smells are heritage smells. In order to identify smells worth studying and preserving, we’ve developed a framework that applies heritage guidelines to the recognition of smells with cultural value.
Once a smell is selected, analytical chemistry techniques are used to extract and analyse the volatile organic compounds (VOCs) present in a sample. These are the techniques we are working with:
Volatile organic compounds (VOCs) are extracted from the headspace around an object using solid phase micro extraction (SPME) and analysed with gas chromatography/mass spectrometry.
Carbon sorbent tubes are used to trap VOCs. The samples are then thermally desorbed and analysed using Time-of-flight chromatography/mass spectrometry.
The human experience of the smell complements the chemical information, characterising the odour by describing and evaluating its intensity and hedonic tone (pleasantness/unpleasantness). These are the techniques we are working with:
Human experience of smells is analysed via trained and untrained panels, which record and rate sensory information including odour descriptors, hedonic tone and intensity using European scales.
A GC with a sniffing port enables the analyst to separately sample many odorous compounds present in the sample. Sensory information including odour descriptors, hedonic tone and intensity is recorded during the session.
Documentation of the smell includes chromatograms, compounds lists, descriptors and sensory information scales. Some of this information is combined into odour wheels.
Preserving the smells for the future involves generating a set of data which enable reproduction of the smell and the sensory experience. An interdisciplinary discussion on preserving smells with cultural value is taking place in 2017 at UCL.