Experiment on extraction and separation of chlorophyll

2022-07-19 0 By

Experimental principle: chloroplast pigments dissolved in organic solvents, such as alcohol or acetone (similar phase solution), according to this principle can be extracted from chloroplast pigments, pigment liquid.The solubility of the four pigments in the chromatography solution is different, so with the different diffusion rate of the chromatography solution on the filter paper, the higher the solubility, the faster the diffusion rate, the lower the solubility, the slower the diffusion rate.According to this principle, various pigments are separated.Chloroplast pigment extraction and separation experiments: ① Extraction pigment principle: pigment can be dissolved in alcohol or acetone and other organic solvents, so the use of anhydrous alcohol and other extraction pigment.(2) Principle of separation of pigment: each pigment with the chromatography liquid diffusion rate is different on the filter paper, so as to separate the pigment.High solubility, fast diffusion rate;Low solubility and slow diffusion.The role of each substance: anhydrous ethanol or acetone: extraction of pigment;Chromatography liquid: separation of pigment;Silica: to ground thoroughly;Calcium carbonate: prevents pigment from being destroyed during grinding.④ Results: From top to bottom, the filter paper is: carotene (narrowest), lutein, chlorophyll A (widest), chlorophyll B (second widest), the width of the pigment band is related to the content of pigment.Extended information: Chloroplasts contain green pigments (including chlorophyll A and chlorophyll B) and yellow pigments (including carotene and lutein).They combine with thylakoid membrane proteins to form pigment protein complexes.They have different chemical structures, so their physicochemical properties (such as polarity, absorption spectrum) and their position and role in photosynthesis are also different.These two kinds of pigments are ester compounds, are insoluble in water, but soluble in organic solvents, so it can be extracted with ethanol, propanol and other organic solvents.The extract can be separated by chromatographic analysis.