Headspace - Thermal Desorption: HS-TD
One flexible analytical system offering the ultimate sensitivity for volatile organics in solids, liquid and gases
HS5-TD™
The HS5-TD system brings together two of the most powerful GC introduction techniques: headspace (HS) and thermal desorption (TD). The combined system offers users optimum sensitivity for trace-level organics in solid, liquid and vapour-phase samples; all on one versatile analytical platform.
The HS5-TD comprises a
manually operated, 5-vial headspace unit integrated with Markes’ state-of-the-art fully-functional UNITY 2 thermal desorber.
This
Dynamic Headspace (DHS) system accommodates up to 5 standard (approx. 20 ml) headspace vials in a common heated zone with manual vial selection for the extraction and concentration of VOCs from liquid or solid samples.
This provides a highly cost-effective solution offering greatly enhanced sensitivity over static headspace alone.
The UNITY thermal desorber can also be combined with a third-party equilibrium headspace unit in order to
automate the HS-TD-GC process.
The following equilibrium headspace units can be integrated into Markes HS-TD system:
- G1888 Headspace system for 70 vials (Agilent Technologies)
- G1290 Headspace system (HP7694) for 44 vials (Agilent Technologies)
- HS40 and HS40XL Headspace sampler for 40 vials (Perkin Elmer) (Note: Not compatible with the PE TurboMatrix HS40)
The HS-TD system also incorporates Markes’ world leading UNITY (single tube) or ULTRA-UNITY (100 tube) thermal desorbers, offering cryogen-free, method compliant TD for sorbent tubes or material samples.
Multi-mode versatility
Markes HS-TD system can be operated in the following modes:
- Automated headspace with trap, offering optimum sensitivity for trace organic volatiles in water, soil and other solid/liquid matrices
- Manual or automated thermal desorption of sorbent tubes and direct thermal desorption of materials
- Conventional automated equilibrium headspace
Headspace-trap for trace level detection
HS-TD increases sensitivity by 1 or 2 orders of magnitude relative to static equilibrium HS, but without any of the foaming or aerosol issues that sometimes accompany purge-and-trap methods.
In many cases, it is possible to exhaustively extract all volatiles, leading to the same order of sensitivity as purge & trap analysis but without limitations such as foaming and mist formation.
The chromatogram shows trace level purgeable VOCs in drinking water analysed by conventional HS (bottom) and HS-TD (top).
Applications
The HS-TD has been applied to the detection of ppt levels of odorants in drinking water. The detailed notes can be downloaded here.
TDTS78: Low ppt levels of geosmin, methyl-i-borneol and other odorants in drinking water using headspace – thermal desorption (HS-TD)
TDTS78b: Supplement to TDTS78 - Low ppt levels of odorants in drinking water using headspace – thermal desorption (HS-TD)