Thermal desorption of odours on sorbent tubes

UNITY, ULTRA 50:50 & AutoSecure TD – manual and automated desorption of odours trapped on sorbent tubes

Markes thermal desorbers are uniquely tailored to meet the stringent requirements of odour analysis.  With a totally inert, short and uniformly heated flow path, Markes thermal desorbers are compatible with reactive compounds such as mercaptans, amines and oxygenated species which often have very low odour thresholds.  The cryogen-free focusing trap allows selective elimination of unwanted, high-concentration interferents which might otherwise compromise trace detection of the target components.  It also prevents ice plugging or blocking the sample flow path during analysis of humid samples.  Systems offer simultaneous analysis of very volatile and semi-volatile compounds with a unique SecureTD-Q facility (quantitative re-collection of split for repeat analysis and method validation) allowing simple validation of the recovery of all analytes through the system.

For detection of trace level target compounds in a complex sample matrix Markes thermal desorbers offer other major benefits.  Efficient focusing trap design allows rapid desorption and splitless, high resolution capillary GC/MS analysis for ultimate sensitivity. The option of back-pressure regulated electronic pneumatic control of carrier gas through the entire TD-GC(MS) analytical system is also available with some leading brands of GC equipment.  Back pressure-regulated ECC locks retention times independent of gas flow, sorbent or TD parameters/status.  This in turn facilitates mass spectral deconvolution and the generation of databases of key target compounds to automate and enhance the analysis of trace target compounds in the presence of high concentration interferences.

Example applications include:

• Sampling vapours from GM foods to check variances in odour profile 
• Quality control of bulk raw materials 
• Sourcing malodour issues – warehousing, transport containers, etc 
• Plant and crop volatiles 
• Analysing whisky headspace

For part numbers and pricing please contact your local Markes distributor

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

• Brochures - UNITY, ULTRA, Air Server - Thermal Desorption Systems 
• Brochure - TubeTAG sorbent tube informatics
• TDTS 32 – Analysis of sulphur compounds using TD-GC(MS) 
• TDTS 46 - Comparing thermal desorption with carbon disulphide (CS₂) extraction of charcoal for air monitoring methods 
• TDTS 52 – The use of TD-GC(MS) in flavour and fragrance profiling and food analysis 
• TDTS 64 – Simultaneous TD-GC(MS) analysis of volatile and sem-volatile organic compounds