Why use glass/quartz wool in splitted injection liners?

The injection of a sample is one of the most critical steps in the GC. In split mode, the injection band must be very small especially for early peaks. At the moment of injection we need to evaporate, homogenize and have reproducible splitting in a fraction of a second. Challenge is that at the point of injection, the temperature decrease rapidly because of the evaporation energy. A perfect scenario for non reproducibility.

That’s why we need to help evaporation by increasing heat capacity, Glass wool does that very well as it has high surface and high thermal capacity: Enough energy to minimize temperature drop and.. reproducibility typically is within 1 %. Such a liner is the Precision liner. Glasswool and liners need to be deactivated. Best position for glasswool in split injection is where the tip of the needle just enters the glasswool, see figure.

For components/matrix that interact with glasswool, take a liner without glasswool but with high surface, like a cyclosplitter.