Gel permeation chromatography (GPC) is a type of size exclusion chromatography (SEC), which separates the analytes according to size, usually in organic solvents. The technique is often used for the analysis of polymers. As a technique, the SEC was first developed in 1955 by Lathe and Ruthven. The term gel permeation chromatography dates back to JC Moore's The Dow Chemical Company who studied the technique in 1964 and proprietary column technology was licensed by Waters Corporation, which was then commercialized in this technology. A number of manufacturers. It is often required to separate polymers, When characterizing polymers, it is important to take into account the dispersity (Ä) of the molecular weight as well. Polymers can be characterized by various definitions of molecular weight, including number average molecular weight (Mn), weight average molecular weight (Mw) (see Molecular weight distribution) or molecular viscosity weight (Mv). The GPC provides the determination of well as well as other data on the basis of Mv, the Mn, the Mw and the Mz can be determined.