Headspace gas chromatography uses headspace gas—from the top or "head" of a sealed container containing a liquid or solid brought to equilibrium—injected directly onto a gas chromatographic column for separation and analysis. In this process, only the most volatile (most readily existing as a vapor) substances make it to the column. The technique is commonly applied to the analysis of polymers, food and beverages, blood alcohol levels, environmental variables, cosmetics, and pharmaceutical ingredients.
