Ionization Techniques; Electron Impact Ionization - Waters GCT Premier Operator's Manual

When the pusher electrode is operated at a repetition frequency of 25 kHz, a
full spectrum is recorded every 40 µs. Each spectrum is summed in the
Embedded PC (EPC) memory until the completed, histogrammed, spectrum is
transferred to the MassLynx PC.

Ionization techniques

Electron Impact ionization

During EI operation, the sample enters the EI inner source via the GC
interface, the solids probe, the DCI probe, or the reference inlet reservoir. The
outer source is heated to vaporize the sample and the resulting gas molecules
are ionized during collision with high-energy electrons, which are released
from a heated filament. The electrons are drawn towards the trap in the
source. The instrument extracts ions from the inner source ion chamber and
introduces them into the analyzer by the ion repeller and the focusing lenses.
See also: Tuning the instrument for EI on page 3-19.
Ionization techniques G-3