Chromatography is a versatile laboratory technique that separates mixtures by exploiting differences in molecular interactions with a stationary phase while dissolved in a mobile phase. It serves both preparative and analytical purposes, with methods like column, ion-exchange, gel-permeation and more, each chosen based on specific separation needs.​ High-Pressure Liquid Chromatography (HPLC) is a powerful analytical tool utilizing pumps to push a sample mixture through a column packed with an adsorbent material. Components separate based on their interaction with the stationary phase.​ RP-HPLC, prominent in pharmaceuticals, employs a non-polar stationary phase and a moderately polar mobile phase, separating molecules via hydrophobic interactions. Retention time correlates with a molecule's hydrophobic surface area.​