Separation techniques include Chemical separation methods, such as extraction and chromatography, are based on chemical interactions between the mixture’s components, or, to be more precise – the differences in the strengths of the interactions of the different materials in the mixture with another material which is not a part of it. Naturally, these interactions are based on the chemical properties of the materials to be separated.
Two types of surface chromatography in frequent use are paper chromatography and Thin layer chromatography. Paper chromatography, the stationary phase is a thin paper strip made of cellulose, on which a tiny drop of the mixture is applied. The paper is dipped in a liquid such as water or ethanol, which ‘climbs’ up the paper due to the capillary force.