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The Thermal Desorption Unit TDU 2 is a thermal desorption system with a broad range of applications. It can be used not only for conventional thermal desorption, but also for direct thermal extraction or direct headspace or Solid Phase Micro Extraction SPME injection into the cold Cooled Injection System CIS. The TDU 2 impresses due to its full temperature control and its compact design with no cold or active points along the sample path. The TDU 2 can be combined with additional GERSTEL modules and therefore forms the basis for a multitude of applications. The operation of the TDU 2 can be automated using the MultiPurposeSampler MPS. The system is controlled using the MAESTRO software.

Functional principle of the TDU 2

The TDU 2 offers a variety of possible applications. During conventional thermal desorption, analytes previously enriched on an adsorbent are thermally desorbed in the TDU 2. During direct thermal extraction, analytes from solid or liquid samples are thermally extracted in the TDU 2. In both cases, the analytes are located inside thermal desorption tubes. During direct headspace or SPME injection, analytes are injected through the hot TDU 2 into the cold CIS and are collected there. Both thermal desorption and thermal extraction are performed in accordance with a temperature program. The temperatures and gas flows within the system can be adjusted individually.


The full temperature control enables analytes to be heated gently and prevents unwanted reactions with atmospheric oxygen. The analytes are specifically separated from the sample matrix. The compact design in accordance with the “liner-in-liner” principle prevents the loss or carryover of analytes and reduces the amount of maintenance required. The system can be expanded further at any time. Using thermal extraction, you can analyze substances that cannot be injected into the GC/MS system directly using a syringe. Thanks to the MAESTRO software, controlling the system as a whole is simple and intuitive.


The PYRO option allows the pyrolysis of sold and liquid samples to be performed automatically during thermal desorption in the TDU 2.