Basic Overview on Gas Chromatography Columns

Gas chromatography (GC) is a separation technique used to isolate volatile components of a mixture depending on differences in the mode of partitioning between a flowing mobile phase and a stationary phase. Because of its simplicity, sensitivity, and effectiveness, GC has earned its place as one of the most important tools in chemistry. Columns/stationary phases are considered the “heart” or “brain” of the chromatograph and are responsible for the separation process. In the GC system, a sample is vaporized and injected into the head of the separation column packed with a finely divided solid or coated with a film of a liquid. When a sample traverses the column by the flow of an inert gas employed as the mobile phase, its components are separated owing to differences in their interactions with the stationary phase. Upon elution from the column, the separated compounds pass over a detector that generates a signal corresponding to the concentration of the compound. The species present can be qualitatively identified based on the delay in the sample passing through the column. Extensive research has led to improved columns for achieving better separation and resolution. Since the initial development of packed columns, many technological advancements have been made. The capillary column was the first advancement in which stationary phases fabricated by using the latest technology was employed.