A Deeper Insight on Silica Gel Chromatography and Thin Layer Chromatography

1. A DEEPER INSIGHT ON SILICA GEL CHROMATOGRAPHY AND THIN LAYER CHROMATOGRAPHY Compounds are mixtures of substances which are not tangible separately but collectively as the compound whole. Separating the substances contained in the compound is called chromatography which is one of the oldest methods to do so. The process of Column Chromatography involves adsorption of the slurry (mixture) in different quantities. The mixture travels upwards and separation is achieved along the way. Silica Gel Column Chromatography involves a glass tube filled with an adsorbent to 1/3 rd of its length. The tube is then introduced into a selective solvent leaving no air space in the tube the arrangement being called a ‘well-packed column’. In this method, the less polar component is washed out first. Additionally, there is a separation affected between the components finishing the procedure of Column chromatography. For the chromatographic separations, the adsorbent is put in a vertical glass column and the blend flows down through the column in the mobile phase. The gravitational power or outside weight is utilized to go the liquid through the column. It gives highly effective outcomes in separating the desired mixture from a blend. The adsorbents, for example, Silica gel and alumina are usually utilized for Column Chromatography.

2. On the other hand, the purpose of Thin Layer Chromatography involves the preparation of a plate of solid adsorbent on which differential adsorption brings about a separation of components of a mixture. The adsorbent used in the TLC process is Silica Gel 400-800 mesh size with or without a binder. The binder employed is usually gypsum that helps the gel to adhere to the plates. For ultraviolet analysis, fluorescence is added to non-colored adsorbent material. The separation of the compounds on the plate is expressed as a retention factor that denotes the distance traveled by the components. Thin Layer Chromatography is used to determine the purity of a substance, identify the components of a compound and observe the progress of a reaction. This is the easiest method available to a chemist to determine how many components are in a compound and how to purify them. The method is used widely in organic chemistry. Silica gel that is mixed with a binder is known as Silica Gel G TLC (gypsum added) while the one with fluorescence is known as Silica Gel GF254.