ABSTRACT
Gas chromatography-mass spectrometry (GC-MS) continues to play a pivotal role in environmental analysis of pollutants despite the increasing use of liquid chromatography-MS by most research groups. This is because of the high separation efficiency of GC and the wide range of mass analyzers that it can be coupled to simplify analysis of pollutants in complex environmental matrices. The first stage in GC-MS is sample introduction. It is important to note that a good injection technique should not compromise the separation efficiency and should not induce a change in the sample composition. The column is the heart of the GC because separation takes place there. Earlier on, packed columns were used, but their use has since been discontinued because of their lower resolution when applied to the analysis of many compounds. Low-pressure GC uses a short microbore column at the injector side, connected to a zero-dead volume connector to a short megabore column to be used with higher gas velocities.
