UNITY, ULTRA 50:50 & AutoSecure for direct desorption of materials 

Direct thermal desorption of materials offers a labour-saving and fully-automated alternative to conventional GC sample preparation methods.  Many different types of material can be weighed directly into an empty thermal desorption tube or tube liner and extracted using heat and a flow of carrier gas.  Volatile and semi-volatile compounds stripped from the sample are selectively concentrated in the UNITY focusing trap while unwanted volatiles (water, ethanol, acetic acid, etc.) are purged to vent.  Sample matrix materials remain behind in the sample tube.  The focusing trap is subsequently heated rapidly in a reverse flow of carrier gas to inject odour components into the analyser in a narrow, concentrated band of vapour, free of volatile or matrix interferences.  

Repeat analysis with reduced split to increase sensitivity

Original analysis







Direct desorption of a leaf - SecureTD-Q allows re-collected sample
to be re-analysed with decreased split ratio to enhance sensitivity.


Markes TD systems are ideally suited to both Research & Development plus routine QA/QC of raw materials and manufactured products.  All systems feature an inert flow path for compatibility with reactive compounds, splitless operation for optimum sensitivity and SecureTD-Q – quantitative re-collection for repeat analysis and validation of analyte recovery through the analytical system. 

Click on UNITY, ULTRA 50:50 and AutoSecure for more details of the Markes range of thermal desorption systems.

Applications include a wide range of relatively homogeneous materials:

• Fragrance in soap powder 
• Essential oils in ointments and creams
• Quality control of dried spice or food preparations
• Odour profiling of dried coffee or cocoa powder
• Residual solvents in printed packaging film

Direct thermal desorption facilitates both exhaustive extraction (e.g. of residual solvents) and representative profiling/characterisation of odours.

For part numbers and pricing please contact your local Markes distributor or visit our on-line shop.

Relevant technical support publications from Markes International can be automatically downloaded from this web site (registration required). Examples include: 

• Brochure - UNITY, ULTRA, Air Server - Thermal Desorption Systems
• Product Sheet - ULTRA 50:50
• TDTS 9 – Monitoring materials and processes for trace level volatile organic compounds 
• TDTS 23 – Utilising multiple desorption methods on UNITY to analyse dry food stuffs 
• TDTS 52 – The use of TD-GC(-MS) in flavour and fragrance profiling and food analysis
  

Back to Food, Flavour & Fragrance home page