|
The
requirements of
analytical chemistry have changed dramatically within the last decade.
The important task of sequencing the human genome in its complexity is
one example that was made possible only by the development of new,
faster and more powerful analytical methods.
The most important detection system in analytical chemistry is the mass
spectrometer. However, for mass-spectrometric (MS) analysis coupled with
gas chromatography (GC), liquid chromatography (LC), or capillary
electrophoresis (CE) separation, the ionization of the separated analyte
molecules must be as quantitative as possible. A variety of ionization
methods have to be used for analytes of different molecular weight and
polarity.
For polar compounds, electrospray ionization (ESI) is the gold standard
with respect to mass spectrometric analysis of small molecules and, due
to multiple charging, for large bio-molecules as well. Analytes with
molecular masses up to several thousand daltons (kDa) and of moderate
polarity are advantageously ionized by atmospheric-pressure chemical
ionization (APCI), while atmospheric-pressure photo-ionization (APPI) or
dopant-assisted (DA)-APPI are frequently applied for the ionization of
non-polar substances. Atmospheric-pressure laser ionisation (APLI),
recently developed by us, is outstandingly sensitive for moderately to
non-polar aromatic compounds.
Currently, classical hyphenated MS methods (e.g., GC-EI/CI MS) are
replaced by systems with couple sample preparation and pre-separation
with high-resolution mass spectrometers equipped with atmospheric
pressure ion (API) sources. There are, however, numerous potential
ion-molecule-reactions occurring in the ion source – particularly within
incompletely separated complex samples. This is mainly due to unspecific
ionization processes in typical API sources. This leads to confusing
spectra and often to noticeable ion suppression. For a successful
analysis with a minimum of ion suppression and disruptive ion-molecule
reactions of complex samples (metabolome, proteome, environment samples,
and natural products), there is a need for a) an error-free sampling, b)
an effective on-line sample preparation, c) a powerful pre-separation,
d) optimised ion sources, e) various types of high-resolution mass
spectrometers and f) high-performance data processing systems.
To this end, iGenTrax offers a multipurpose ion-source for various
Bruker- and Agilent-MS systems which allows to realize the following
couplings with an API-MS-system:
|
 |
 |
|
- LC-APLI
-
LC-APCI
-
LC-APPI
-
LC-ESI
-
LC-ESILI (combination
of ESI and APLI) |
-
GC-APLI
-
GC-APCI |
|
