This document discusses high performance thin layer chromatography (HPTLC), comparing it to traditional thin layer chromatography (TLC). HPTLC involves the same principles as TLC but with some key improvements like smaller particle sizes, faster separations, and the ability to perform quantitative analysis using scanning densitometry. The document outlines the basic steps of an HPTLC procedure including sample preparation, selecting the chromatographic layer, pre-washing and pre-conditioning the layer, applying the sample, developing the plate, detecting spots, scanning, and documentation. It also discusses factors that affect the separation like the mobile phase composition and saturated vapor. HPTLC is described as having applications in pharmaceutical analysis, cosmetics analysis, and