In capillary gas chromatography, injecting as large a volume of sample as possible is an attractive means of reducing the sensitivity limitations. The conventional inlet system is the hot Split/Splitless Inlet, which, when kept at a sufficiently high temperature, allows the sample to evaporate immediately after injection, thereby enabling it to be transferred into the separation column. If, however, the volume of vapor generally caused by excessive quantities of solvent is greater than the capacity of the inlet system, the transfer of the analytes may be severely impeded, if not prevented altogether.
This disadvantage of the conventional hot injection techniques can be circumvented through the use of a GERSTEL Cooled Injection System (CIS), a temperature-programmable split/splitless inlet. The sample is injected into the cold CIS when the split is open. At that time, the temperature is high enough to evaporate the solvent and remove it via the split gas outlet but is also low enough to hold the analytes in the liner of the CIS. The split is then closed and the CIS is heated up to the temperature required for the analytes to be transferred.
The GERSTEL MultiPurposeSampler MPS in conjunction with the GERSTEL MAESTRO software and its integrated Solvent Vent Calculator ensures that the sample is injected at the optimum speed that is appropriate to the solvent being used.