The high mass resolution of IONICON’s PTR-TOFMS series can now be complemented by a fast gas chromatographic pre-separation step. This new fastGC add-on augments your data with another dimension of chemical information, allowing to separate isomeric compounds, while maintaining fast spectral runs.
In a gas chromatographic (GC) column, compounds are separated in retention time according to their chemical properties. In contrast to classical GC, spectral runs in less than one minute are possible with the IONICON fastGC module, providing near real-time data. The fastGC is an add-on for IONICON PTR-TOF systems and uses the same sample inlet. The fastGC mode can be activated when required while not affecting the regular PTR-TOF operation otherwise. It can also be used to eliminate the influence of high concentrations of matrix compounds, e.g. ethanol in beverages, and to study fragmentation and interferences.
The main hardware parts of the IONICON fastGC are: a resistively heated column, a pneumatically operated 10-port valve, two mass flow controllers and the fastGC Inlet. The setup is configured in a way that it can be switched between two states: the OFF- and ON state. During the OFF state the column is connected to the off-gas and the sampling loop is constantly flushed (with 10-20 sscm flow) by the same sample gas connected to the PTR-TOF inlet.
What makes the fastGC “fast”?
The duration of a GC analysis is limited by the last compound eluting the column. This can be sped up by heating the column following defined temperature ramps. With typical ramp speeds of 30°C/minute in conventional GC systems this results in run-times of several ten minutes. Moreover, the column and its surrounding oven need to cool down before the next run can be initiated.
IONICON’s fastGC system uses columns of approx. 10 m, but the key to fast spectral runs is the innovative heating system: the metallic column is resistively heated, keeping the thermal mass at a minimum. This allows for fast heating rates of >15°C/second (1200°C/minute) AND cooling rates of >10°C/second allowing spectral runs in < 1 min.
Integration and Usability
The fastGC control software allows changing parameters, configuring temperature ramps, and to initiate (also repeated) fastGC runs. The software is tightly interconnected with the PTR-TOF operation software to synchronize fastGC runs and data acquisition.