Automated Dynamic Headspace DHS is available for the GERSTEL MultiPurpose Sampler MPS. The DHS station efficiently extracts and concentrates VOCs from liquid or solid samples placed in standard Headspace vials (DHS) or in larger sample containers up to 1 L volume (DHSLarge). The sample is thermostated and agitated while the headspace is purged with a controlled flow of inert gas, providing controlled and efficient extraction conditions. Sample temperatures can be selected from 10 °C to 200 °C. Lowering the temperature provides a means of reducing the amount of water vapor released and ultimately retrapped. The DHS station additionally holds a replaceable adsorbent- or sorbent filled tube used for analyte concentration. The temperature of the adsorbent tube during the DHS process can be varied from 20 °C to 70 °C for optimal trapping of the analytes in question.
Adsorbent tubes used are standard GERSTEL Thermal Desorption Unit TDU tubes. Following analyte concentration, the tube is automatically transferred to the TDU for Thermal Desorption and analyte transfer to the GC. Tubes are fitted with individual adapters enabling both automated movement and leak-free sealing during the Dynamic Headspace and Thermal Desorption steps and during storage in the autosampler tray.
Automated Dynamic Headspace DHS combined with sample introduction to a GC or GC/MS system is performed by the MPS and TDU. Up to 98 samples can be processed automatically in one sequence.