Direct Inlet for Headspace Vapours
Multi-purpose direct inlet accessory
The UNITY thermal desorption units for the analysis of single sorbent tubes can be upgraded with a direct inlet accessory, facilitating discontinuous online sampling of headspace vapours above bulk products. Options include carrier gas purge of sealed sample vessels or pulling a fixed flow of air through open sample chambers – for example vessels containing living organisms – microbes, blossom, insects, etc. Vapour-phase odour components are transferred from the sample container directly into the electrically-cooled sorbent focusing trap of the thermal desorption system.
Greatly enhanced sensitivity
Use of UNITY with the Direct Inlet accessory greatly enhances sensitivity relative to conventional headspace – allowing large volumes of vapour to be focused before subsequent analysis. It also allows characterisation of more representative odour profiles (i.e. covering a wider volatility range) because continuous, dynamic extraction of vapours prevents the bias towards more volatile compounds observed with equilibrium headspace methods. Selective elimination of unwanted, high concentration interferences such as water or ethanol is also possible.
Applications
Key application areas include:
- Characterisation of VOC profiles from natural products and manufactured goods - food, flavour, fragrance analysis
- Measurement of residual volatiles in materials
- Monitoring emissions from living organisms - plants, microbes, fungi, insects, etc.
- Monitoring trace VOC pollutants in environmental water and soil samples
- Off-odour/shelf-life testing
- Monitoring organic vapour products from gas phase reactions.
Versatility
The UNITY-Direct Inlet system is compatible with a wide range of sample vessels. It may be used for purging of headspace vapours from smaller, sealed containers (such as reaction vessels or headspace vials) or for pumping vapours from open or compressible containers such as bell jars or gas sampling bags.
For part numbers and pricing please contact your local Markes distributor
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