Experiment Chromatography : Using The Concentration Of Compounds And Helps Identify The Substances Within It

1417 Words6 Pages
Chromatography Different types of Chromatography Paper chromatography Paper chromatography is a method of testing the purity of compounds and helps identify the substances within it. Using the paper chromatography is a useful and simple technique as it is relatively quick and requires small quantities of material. Paper chromatography separates colours, this also happens in the thin layer chromatography. Using the paper chromatography method, substances the distribution between stationary phase and a mobile phase. Stationary phase usually requires a piece of high quality filter paper. As for the mobile phase, this develops the solution as it travels up the stationary phase, this will be carrying the samples with it. The components within…show more content…
The mobile phase the slowly rises up the TLC plate by the capillary action. Whilst the solvent is pasted the spot that was applied, a balance is then recognised between the components of mixtures as the molecules of a component which is then adsorbed on the solid and the molecules which are in a solution. However, the components within the solubility will then differ and the strength of their adsorption to the adsorbent and some components will then be carried upwards on the plate than others. When the solvent has reached to the top of the plate, it is then removed from the chamber, it is then dried up and the components is separated and it is visible on the TLC plate. Most of the times the colours are easily visualized but sometimes there aren’t as many colours on it therefore, a UV lamp is used to detect the plates. Gas Chromatography Gas chromatography is a method that separates the components of a solution and measuring the relative quantities. The useful technique of gas chromatography is for chemicals that do not decompose at high temperatures and when a very small quantity of sample (micrograms) is available. Gas chromatography uses are limited as the decomposition temperature of components within a mixture and the composition of the column; columns cannot withstand temperatures that are above 250-350 ¬oC. By doing a gas chromatography, a sample is heated as well as being vaporized at the injection port. Through the column,
Open Document