{"id":462,"date":"2017-11-14T12:21:57","date_gmt":"2017-11-14T12:21:57","guid":{"rendered":"http:\/\/chemdictionary.org\/?p=462"},"modified":"2017-11-14T12:24:35","modified_gmt":"2017-11-14T12:24:35","slug":"paper-chromatography","status":"publish","type":"post","link":"https:\/\/chemdictionary.org\/paper-chromatography\/","title":{"rendered":"Paper chromatography"},"content":{"rendered":"

Introduction to paper chromatography<\/h2>\n

Paper chromatography is a chromatography technique used to separate mixture of chemical substances into its individual compounds. Paper chromatography is used to teach TLC or other chromatography as it is very similar to TLC.<\/p>\n

<\/h2>\n

Principles of paper chromatography<\/h2>\n

All chromatography follow the same principle. Paper Chromatography consists of two phases: one mobile phase and one contiguous stationery phase. The stationery phase a paper and the mobile gas is solvent. The compound mixture moves along with the mobile phase through stationery phase and separates depending on the different degree of adhesion (on the paper) of each component in the sample or the compound mixture.<\/p>\n

Explanation<\/h3>\n

The stationery phase<\/h3>\n

The paper chromatography is very similar to Thin layer chromatography. Difference is, instead of using a thin layer of silica on metal, it uses a special type of chromatography paper as stationery phase. This paper is made of cellulose. Cellulose is a polymer of simple sugar, glucose.<\/p>\n

\"By<\/p>\n

Cellulose contains -OH group similar to the silica or alumina on the TLC plate.\u00a0The surface of cellulose is thus very polar. So the compounds can form hydrogen bond or can interact by van der waals dispersion forces and dipole dipole forces.<\/p>\n

Process<\/h3>\n

Paper chromatography works in few steps:<\/p>\n

Step 1:<\/strong><\/em>\u00a0A horizontal line is drawn near one end (about 1.5 cm from the bottom edge) of the paper. In figure below 6 is the horizontal line.<\/p>\n

\"By<\/p>\n

Step 2:<\/strong><\/em>\u00a0The sample needs to be separated is placed as a small drop or line on to the paper using capillary tube. Labelling the drop by a pencil with an alphabet or number help to identify the compound later. In figure above 3 and 4 are the drops labelled. The drops are then soaked on the paper and dried.<\/p>\n

Step 3:<\/strong><\/em>\u00a0The paper is then placed into a sealed container with a swallow layer of\u00a0 suitable solvent. The solvent level must be lower than the pencil line or drop on it. The container need to be covered to stop the solvent to evaporate.<\/p>\n

<\/p>\n

Step 4:\u00a0<\/strong><\/em>The solvent rises up the paper chromatography taking each component of the sample with it. The components travel with the solvent depends on three things:<\/p>\n