Choosing a stationary phase is the most important step in choosing a column, and should be selected based on the application to be performed. It is recommended to first consult our "Capillary GC Columns, by industry/application" section to determine if we have already identified appropriate columns. For new applications, there is often no existing reference to provide guidance. In these method development instances, one must have some knowledge of the chemistry of the compounds to be analyzed. Phase selection is based on the general chemical principle that "likes dissolves like" and relates to the specific analyte-stationary phase interactions that each group of columns can perform. Choose:
Non-polar GC columns for non-polar compounds (such as alkanes) that contain 1) only carbon and hydrogen atoms, and 2) only single bonds between carbon atoms.
Intermediate polar GC columns for an alternate selectivity of non-polar and/or polar compounds.
Polar GC columns for polar compounds (such as alcohols, amines, carboxylic acids, diols, esters, ethers, ketones, and thiols) that contain 1) primarily carbon and hydrogen atoms, and 2) also some bromine, chlorine, fluorine, nitrogen, oxygen, phosphorus, and/or sulfur atoms.
Highly polar GC columns for polarizable compounds (such as alkenes, alkynes, and aromatic hydrocarbons) that contain 1) only carbon and hydrogen atoms, and 2) some double and/or triple bonds between carbon atoms.
Extremely polar GC columns for additional selectivity of polarizable compounds.
;)
