Odour profiles (comprising volatile organic chemicals) play a major part in our perception of foods, beverages and consumer products.  Given the sensitivitiy of the human nose, it follows that much of the routine industrial quality control and a significant portion of the research carried out in these fields, is focused on ensuring that products are pleasing to the senses as well as being safe to use – i.e. free from both toxic and malodorous compounds.

Analytical thermal desorption (TD) is widely used for food, flavour and fragrance profiling.  It provides sufficient (and selective) concentration enhancement (concentration factors up to 10⁶) to facilitate detailed chemical analysis of odour profiles using standard analytical tools, thus complementing olfactometry.  Analytical TD is compatible with a wide variety of sample matrices and allows selective elimination of unwanted, high concentration interferences such as water, ethanol or acetic acid.  It provides a convenient, automated alternative to conventional sample preparation methods such as solvent extraction, steam distillation or static headspace and combines with laboratory GC, GC-MS, MS or enose technology to provide a complete sample preparation and odour analysis package. 

Markes inert, short flow-path TD systems and related sampling equipment are uniquely adapted to food, flavour and fragrance profiling and are suitable for both research and routine QA/QC applications.  Key products include: 

1. UNITY 2 – Platform thermal desorber for single tagged or untagged tubes (3.5-inch or 4.5-inch). UNITY 2 is a cryogen-free two-stage desorber for single sorbent tubes (pumped or diffusive) and features (SecureTD-Q) quantitative re-collection for repeat analysis.
   
   
2. ULTRA 2 - ULTRA 2 adds to Markes UNITY 2 TD platform to provide automatic desorption of up to 100 industry standard (3.5-inch) or DAAMS (4.5-inch) tubes with or without RFID tags. ULTRA 2 units also have a tag read/write facility.
   
   
3. Direct Inlet for low-cost discontinuous on-line monitoring of vapour profiles as they change with time .
   
   
4. TT24-7 twin-trap technology for continuous on-line monitoring – ideal for monitoring rapid changes in odour profile. 
   
   
5. Series 2 (ULTRA-)UNITY for direct desorption / extraction of volatiles from consumer products such as toothpaste, ointments, spice and packaging film .
   
   
6. Micro-Chamber/Thermal Extractor for odour profiling of bulk materials at ambient or elevated temperatures. 
   
   
7. SPE-tD cartridge for solid-phase extraction of volatile and semi-volatile organics from liquid sample preparations. 
   
   
8. Enhanced data processing tools looking for target compound ‘needles’ in complex chromatographic ‘haystacks’.
   

Markes TD systems can be connected to any make of GC(MS) including systems from Agilent Technologies, Perkin Elmer, Shimadzu, Thermo Electron and Varian.

Available free of charge to all TD users:
Thermal Desorption: A Practical Applications Guide. IV Food, Flavour, Fragrance & Odour Profiling. Click here for further information