Thermal Desorber TD 3.5+

Offering more for Material Emissions-, Flavor-,
and Air analysis

The Thermal Desorber TD 3.5+ is a flexible automated solution for thermal desorption and thermal extraction. The TD 3.5+ fits on top of any modern GC without the need for additional bench space and it is perfectly suited for the analysis of material and for thermal desorption of sorbent tubes used to sample whole air. The TD 3.5+ handles standard 3.5” tubes, as prescribed in several standard methods, in addition to GERSTEL plus tubes, which hold up to 20 % more sorbent for enhanced break-through volume, improved recovery as well as improved limits of detection.

The TD 3.5+ incorporates the latest advances in thermal desorption technology. Intelligently designed and based on a “Liner-in-Liner” concept it has no valves or transfer lines. The TD 3.5+ is connected directly to the GERSTEL Cooled Injection System (CIS), which serves both as a cryo-focusing trap and as a temperature programmable GC inlet. Active sites are eliminated, reducing the risk of analyte loss, discrimination and memory effects to an absolute minimum.

The TD 3.5+ can be operated in single split, dual split or true splitless mode enabling it to cover the widest range of concentrations, to protect the column from water and contamination and to achieve the lowest possible limits of detection. The TD 3.5+ low-flow split pneumatics provide improved flexibility and performance. For extreme sensitivity, the multi-desorption mode can be selected in MAESTRO.

Techniques supported by TD 3.5+:

  • Thermal desorption of adsorbent tubes used for air sampling
  • Dynamic Headspace (DHS 3.5+) based on standard headspace vials
  • DHS 3.5+ Large based on sample containers up to 1 L volume
  • Thermal extraction of solid samples placed in fritted TD tubes
  • Stir Bar Sorptive Extraction (SBSE) using the GERSTEL Twister®
  • Thermal extraction of liquids placed in µ-vials inside the TD tube

The TD 3.5+ supports manual operation and it can be removed in seconds to enable direct liquid sample introduction into the GERSTEL Cooled Injection System (CIS), a PTV-type universal GC inlet.
When configured with the GERSTEL MultiPurpose Sampler (MPS robotic), up to 40 samples are stored per TD 3.5+ tray in individually sealed sample positions. The system can easily be scaled up by using up to three TD 3.5+ trays per tray holder. The number of tray holders depends on size and configuration of the MPS robotic.

Automated micro-scale chamber

In the DHS L 3.5+, samples are placed in individual inert chambers with a volume of up to 1 Liter at defined temperature and air exchange. Analytes are automatically collected at user-defined intervals followed by thermal desorption in the new TD 3.5+ and GC/MS determination. Emission profiles can be established automatically and automated spiking of standards onto sorbent tubes can be performed for calibration and qualification purposes using the TSS option for MPSrobotic . GERSTEL tubes with up to 20 % more sorbent can be used for improved analyte recovery, higher breakthrough volume, and lower limits of detection.

Samples can be analyzed in one automated sequence using one or more methods. The MAESTRO software combined with the Agilent ChemStation controls the complete process from sample introduction through thermal desorption to GC/MS analysis with one method and one sequence table ensuring efficient and error-free operation.