What principle is chromatography based on?

Chromatography operates on the principle of separation based on differences in affinity for a stationary phase and a mobile phase. In this technique, the mixture to be separated is dissolved in a mobile phase (which could be a liquid or gas) and then passed through a stationary phase (which could be a solid or a liquid supported on a solid).

The components of the mixture interact differently with the stationary phase and the mobile phase due to their unique chemical properties, such as polarity, size, and solubility. Those that have a higher affinity for the stationary phase will move more slowly, while those with a greater affinity for the mobile phase will travel faster. This differential movement causes the components to separate as they move through the system, allowing for their identification and quantification.

This principle is essential in various applications, including separating biological molecules, analyzing environmental samples, and purifying chemical substances.