CHROMATOGRAPHY PAPER

CHROMATOGRAPHY PAPER

• Laboratory grade chromatography paper.

(Wikipedia excerpt: ... "Paper chromatography is an analytical method used to separate colored chemicals or substances. It can also be used for colorless chemicals that can be located by a stain or other visualisation method after separation.[1] It is now primarily used as a teaching tool, having been replaced in the laboratory by other chromatography methods such as thin-layer chromatography (TLC).
This analytic method has three components, a mobile phase, stationary phase and a support medium. The mobile phase is a solution that travels up the stationary phase by capillary action. The mobile phase is generally a mixture of non-polar organic solvent, while the stationary phase is polar inorganic solvent water. Here, paper is used to support the stationary phase, water. Polar water molecules are held inside the void space of the cellulose network of the paper. The difference between TLC and paper chromatography is that the stationary phase in TLC is a layer of adsorbent (usually silica gel, or aluminium oxide), and the stationary phase in paper chromatography is less absorbent paper.
A paper chromatography variant, two-dimensional chromatography, involves using two solvents and rotating the paper 90° in between. This is useful for separating complex mixtures of compounds having similar polarity, for example, amino acids.... "