5
Overview of Internal Configuration
The Internal configuration is one of the three operational configurations of the
4000 GC/MS system. In this configuration, it is possible to collect either electron
ionization or positive chemical ionization (EI or PCI) data. Unlike the External
Ionization configuration, it is possible to collect EI or PCI data during different
time segments of a single chromatographic acquisition. However, it is not
possible to collect Negative Chemical (NCI) data in Internal configuration. In
common with the other configurations, it is possible to perform ion preparation
techniques including Selected Ion Storage (SIS) or with optional software and
equipment, Tandem Mass Spectrometry: (Automated Methods Development
(AMD), MS/MS, MS
n
, and Multiple Reaction Monitoring (MRM). Refer to the 4000
GC/MS Software Operation Manual for on-line help information on setting up
these experiments.
The 4000 GC/MS analyzes the gas-phase ions formed from a sample in terms of
their mass-to-charge (m/z) ratios and their relative abundances in the resulting
spectra. The mass spectrum is a graphical representation of the ion intensities
versus the mass-to charge ratio.
The 4000 GC/MS creates the mass spectrum with an ion trap analyzer. The ion
trap confines the ions within a single region where time-dependent
electromagnetic fields control ion processes.
E.M.
Endcap
Ring Electrode
Transfer
Line Tip
Filament
Endcap
Filament
Electron Gate
Electron Multiplier
H.E.D.
Summary of Contents for 4000 MS
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