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 congested 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: