Gas Chromatographic Columns

In gas chromatography the mobile phase is a gas. Gas chromatographic columns are usually between 1 and 100 meters long. Gas liquid chromatography(GLC): The liquid stationary phase is bonded or adsorbed onto the surface of an open tubular (capillary) column, or onto a packed solid support inside the column. Matching the polarities of the analyte and stationary phase is not an exact science. The two should have similar polarities. The thickness of the stationary phase ranges between 0.1 and 8 µm. The thicker the layer the more volatile the analyte can be.