Chromatography separates a mixture by causing its components to move at different rates. Chromatography papers are composed of cellulose and are used to separate chemicals for analysis. Column chromatography separates individual chemical compounds from mixtures. In Gas Chromatography (GC), the sample is vaporized, injected into a carrier gas, and passed through liquid in a column for separation. In High-Performance Liquid Chromatography (HPLC), the sample is mixed with a solvent and passed through a column with adsorbent material for separation.