1-6 Instrument Description
Inlets
GC interface for EI/CI
The GC interface provides a heated transfer line between the GC (gas
chromatograph) and the ion source. The transfer line ensures even heating
which prevents the sample from condensing in the GC column before it
reaches the ion source.
See also: Chapter 6 The GC Interface and the appropriate operator’s guide
for GC operation details.
GC interface for FI/FD
The GC-FI interface provides a transfer line between the GC (gas
chromatograph) and the FI/FD ion source. The end of the column is positioned
approximately 2 mm from the emitter wire on the FI/FD inner source.
The sensitivity of analytes introduced via the GC can be reduced if the end of
the column is not close to the emitter.
See also: Chapter 9 FI/FD Operation.
Direct insertion (DI) probe
The direct insertion (DI) introduces solid or liquid samples not sufficiently
volatile for injection via the reference inlet, into the ion source. The DI probe
is inserted into the instrument source via the probe insertion lock, which must
be fitted to the instrument prior to using the probe.
See also: Chapter 7 The Direct Insertion Probe.
Direct chemical ionization (DCI) probe
The direct chemical ionization (DCI) probe is used for relatively nonvolatile
samples. Like the DI probe, the DCI probe is inserted into the instrument
source via the probe insertion lock, which must be fitted to the instrument
prior to using the probe. The DCI probe is used with the DCI inner source,
rather than the standard CI inner source. The DCI probe can also be used
with the EI inner source.
See also: Chapter 8 The Direct Chemical Ionization (DCI) Probe.
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