In gas chromatography an analyte (gas phase sample) is transported by a carrier gas (H2, N2, He) through a column. The stationary phase is typically a liquid, sometimes solid, bonded to the inside of the column (gas-liquid vs. gas-solid chromatography). Columns have inner diameters between 0.1-0.5 mm and can be 15 to 100 m long. Samples are injected through a septum into a heated port as either volatile liquids or gases to be rapidly evaporated. The degree to which the analyte (sample) sticks to the stationary phase (column wall) changes how quickly each component moves through the column. The stationary phase is chosen based on the identity of components to be separated. The components exit the column eventually and enter a detector and the response from the detector is displayed as peaks on a computer which can be quantified based on an internal standard which is added to the sample.Temperatures in the column and detector must remain high enough to keep the components in the gas phase.