Programmable temperature vaporizer injectors

The TDU equipment (commercially available from Gerstel GmbH, Miilheim an der Ruhr, Germany) is fully automated and connected on-line to a GC equipped with a programmable temperature vaporizer (PTV) injector for simultaneous cryotrapping of the analytes before injection. Another approach for analyte desorption is to place the stir bar in a small volume of a conventional HPLC liquid (or mobile phase) for HPLC analysis. The SBSE stir bars are trademarked as Twisters they can also be purchased from Gerstel. For more detailed information on SBSE technology, the reader is referred to two recent review articles.44 45... 

In SFE-GC coupling, the main fiictor to be considered is the flow rate of the fluid, which increases upon depressurization by a frtctor of about 400. The interfiK es used in SFE-GC are typically based on a split/splitless injector, an on-column injector or a programmable temperature vaporizer (45-57). In principle. 

For sample introduction in HTGC, split, splitless, on-column injection, or combinations of the latter, the programmable temperature vaporizing (PTV) injector are suitable. Howeveq with the exception of cold on-column injection, none of these introduction systems fulfill the requirements of an adequate HTGC injection device and guarantees reliable results. 

When GC is being used, possible contamination of the system (injector and column) with nonvolatile polymeric material is the main issue. One option is to allow direct introduction of a polymer-containing sample (solution), but to confine the polymer to a removable part ( hner ) of the injection system. On some injection systems (specifically programmable-temperature vaporizers, or PTVs), a series of injections may be performed before the quantitative analysis of monomer is jeopardized and the liner needs to be replaced. Such an approach may be acceptable if... 

The PTV injector (programmable temperature vaporizer, also called multimode inlet) with split or splitless operation is based on the systematic work of Vogt (1979), Poy (1981) and Schomburg (1981) (Figures 2.65 and 2.66). In particular, emphasis was placed on the precise and accurate execution of quantitative analyses of complex mixtures with a wide boiling point range (Poy, et al., 1981,... 

---