Paper chromatography Essay Example for Free

Paper chromatography EssayAim to separate and identify of the paints in leaves by cover chromatography commandment of designIn this experiment, a strip of penetrate paper containing a small spot of concentrated chlorophyll pigment is dipped in a mixture of developing outcome, the pigments was carried up the strip as the solvents move up. Since the solvents moved at different rates and pigments had different solubilities in them, the pigments gradually become separated. When the solvent was near the top of the paper, the paper was removed. After that, Rf (Relative preceding) for that substance were calculated. In this experiment, Rf values were used to identify the different substances present in the click extract mixture.Instructions1. 3 leaves of spinach were ground in pestle and mortar by 2 cm3 of extraction solvent2. the developing solvent was added into the change state tube and it just touched the bring down edge of the paper strip.3. The tube was kept stopper to al low it to saturate with the solvent vapour4. Both sides of paper strip were trimmed to make sure that the sides of paper strip didnt touch the sides of the boiling tube5. A light pencil line was ruled 20mm from the lower edge of paper strip6. A capillary tube was dipped into the extract and a small drop of the extract was put in the mediate of the starting line. When it was dried, another drop was added and adding was continued until the spot was quite dark. The spot was kept as small as possible.7. One end of the strip was folded at 90 so that when the paper strip was suspended with a pin from the stopper, the opposite end would just dip into the surface of the solvent.8. The chromatogram was allowed to develop until the solvent front is 2 cm from the upper edge of paper strip.9. The paper strip was taken out and a light pencil line was ruled to sap the solvent front.10. The pigment patches were circled immediately with a pencil.11. The Rf values for the different pigments in the leaf extract were calculated.ResultsThe distance that the solvent travels = 9.3cmRf of the top yellowed spot = 8.9/ 9.3 = 0.96cmRf of the middle orange spot = 6.8/ 9.3 = 0.73cmRf of the bottom bright green spot = 5.7/9.3 = 0.61cmRf of the final green spot = 4.4/9.3 = 0.47cm accordingly the top yellow spot is carotene pigment, the middle orange spot is xanthophyll pigment, the bottom bright green spot is chlorophyll a pigment, and the lowest green spot is chlorophyll b pigment.DiscussionChromatography is an effective method of separating the solutes in a solution. Paper chromatography is the process we used to separate various chemicals set in motion in the pigment, in the case is chlorophyll. The four pigments that being separated were chlorophyll a, chlorophyll b, xanthophyll II, and carotene. These pigments were each separated at a different full point on the paper. This is because of few different factors.First, each pigments has a different mass, and therefore are heavier a nd cannot travel up the paper as far, or as quickly. In this experiment, the heaviest pigment is chlorophyll b as it is the lowest, and the lightest pigment is carotene as it is the top of all pigments.The second factor was the solubility of the pigment. The least oil-soluble pigment should travel up the shortest distance, and the most soluble pigment should travel up the longest distance. In this experiment, the least soluble pigment was chlorophyll b, and the most soluble one was carotene.The third factor was adsorption, that is the energy to attract other substances strongly and hold on their surface. The pigment with the greatest adsorption ability traveled up the shortest distance, and the pigment with the weakest adsorption ability traveled up the longest distance. In this experiment, carotene had the weakest adsorption ability, and chlorophyll b had the greatest adsorption ability.The strip of filter paper should be freely suspended in the test tube, this is because the mov ement of the pigment on the paper in contact or near the glaze over would cause the particles to be attracted to the side such that net charge of the force would be towards the side.The test tube must be stoppered. This is to produce a stark(a) atmosphere in the test tube. Also, it was to prevent the evaporation of the solvent, which is toxic.ConclusionThere were four pigments being separated from chlorophyll, they were chlorophyll b, which is the least soluble, heaviest and have the greatest ability of adsorption, chlorophyll a, xanthophyll II and carotene, which is the most soluble, lightest and have the weakest ability of adsorption.