What does chromatography primarily separate?

Chromatography is a technique widely used in chemistry and biology to separate components of a mixture based on their different interactions with a stationary phase and a mobile phase. When a mixture is applied to the column or medium, different components move at different rates, allowing them to be separated from one another.

In this process, various factors such as molecular size, solubility, and adsorption affinity come into play, leading to the effective separation of the individual components within the mixture. This is particularly useful for analyzing complex mixtures in a wide range of applications, from pharmaceuticals to environmental science.

Other options, while they may involve separation processes in some contexts, do not capture the specificity of what chromatography does. For instance, separating solids from liquids is more characteristic of filtration, and separating different types of gases or radicals from compounds involves other analytical techniques. Thus, the primary function of chromatography is indeed the separation of components of a mixture, confirming the choice as the most accurate answer.