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Chlorophyll is a natural edible pigment extracted from clover, nettle and dried silkworm sand. The main ingredients are chlorophyll a, chlorophyll b and sodium copper chlorophyllin. Chlorophyll is dark green viscous substance, which is easily soluble in water and various organic solvents. Under neutral or alkaline conditions, the color tone is stable green.
1. Chlorophyll is used for coloring soap, mineral oil, wax and essential oil.
2. Derivatives of chlorophyll or folic acid, such as copper chlorophyllin, sodium iron chlorophyllin, sodium copper chlorophyllin, are used as colorants and deodorizers in food, candy, beverages, toothpaste, etc.
Chlorophyll is divided into chlorophyll a, chlorophyll b, chlorophyll c, chlorophyll d, chlorophyll f, protochlorophyll and bacterial chlorophyll.
1. Extraction
The preparation of chlorophyll extraction is in a semi-dark room, and the room temperature is kept at 25 ℃. The extraction steps are as follows:
(1) Take 1000 grams of fresh green leaves and crush them in a Webster stirrer.
(2) Put 1000 grams of crushed green leaves into acetone with a small amount of calcium carbonate (temperature 20 ℃) for extraction until the filtered and cleaned leaf fragments are colorless.
(3) Put the filtered acetone extract into a funnel containing 1 liter of petroleum ether and 100 mL of acetone, then gently rotate it, and add distilled water until it is layered. Most acetone and water-soluble impurities in the water layer are discarded, leaving only petroleum ether solution.
(4) After the petroleum ether solution is purified again with distilled water, clean it with 200 mL 80% methanol solution containing petroleum ether and 0.01 g oxalic acid for more than 5 times, and finally obtain a yellow-green suspension.
(5) Dry the suspension with anhydrous sodium sulfate, and infiltrate it into a column made of 3 cm thick sucrose powder, and then wash the precipitated pigment with petroleum ether to remove carotenoids, so that it only contains natural chlorophyll.
(6) The sucrose column containing natural chlorophyll is divided into two layers, the green layer has 4-10mm chlorophyll b layer, and the other blue layer is 2-6mm chlorophyll a layer.
(7) Put the part in the middle of the blue layer (about half of the blue layer) into the ether, filter and elute the suspension, wash it with distilled water, dry it with sodium sulfate, and filter it with a vessel to obtain chlorophyll a.
(8) Remove the middle part of the green layer in (6), quickly put it into the ether for filtration and elution, and make chlorophyll b ether solution.
2. Separation
Chromatography is an important method for separation, purification and identification of organic compounds, especially in microanalysis. Pigments in fruits and vegetables mainly include fat-soluble carotene, lutein, chlorophyll and water-soluble anthocyanins. In the extraction experiment, we can use the principle of similar phase solubility to filter out water-soluble anthocyanins, and then use thin layer chromatography, column chromatography, and high performance liquid chromatography to separate carotene, lutein, and chlorophyll. Because the polarity of these three pigments is weakened in turn, we can appropriately select a single organic solvent or a mixed solvent with different proportions as the developing agent and eluent, and determine the best separation conditions.
Chlorophyll is a natural edible pigment extracted from clover, nettle and dried silkworm sand. The main ingredients are chlorophyll a, chlorophyll b and sodium copper chlorophyllin. Chlorophyll is dark green viscous substance, which is easily soluble in water and various organic solvents. Under neutral or alkaline conditions, the color tone is stable green.
1. Chlorophyll is used for coloring soap, mineral oil, wax and essential oil.
2. Derivatives of chlorophyll or folic acid, such as copper chlorophyllin, sodium iron chlorophyllin, sodium copper chlorophyllin, are used as colorants and deodorizers in food, candy, beverages, toothpaste, etc.
Chlorophyll is divided into chlorophyll a, chlorophyll b, chlorophyll c, chlorophyll d, chlorophyll f, protochlorophyll and bacterial chlorophyll.
1. Extraction
The preparation of chlorophyll extraction is in a semi-dark room, and the room temperature is kept at 25 ℃. The extraction steps are as follows:
(1) Take 1000 grams of fresh green leaves and crush them in a Webster stirrer.
(2) Put 1000 grams of crushed green leaves into acetone with a small amount of calcium carbonate (temperature 20 ℃) for extraction until the filtered and cleaned leaf fragments are colorless.
(3) Put the filtered acetone extract into a funnel containing 1 liter of petroleum ether and 100 mL of acetone, then gently rotate it, and add distilled water until it is layered. Most acetone and water-soluble impurities in the water layer are discarded, leaving only petroleum ether solution.
(4) After the petroleum ether solution is purified again with distilled water, clean it with 200 mL 80% methanol solution containing petroleum ether and 0.01 g oxalic acid for more than 5 times, and finally obtain a yellow-green suspension.
(5) Dry the suspension with anhydrous sodium sulfate, and infiltrate it into a column made of 3 cm thick sucrose powder, and then wash the precipitated pigment with petroleum ether to remove carotenoids, so that it only contains natural chlorophyll.
(6) The sucrose column containing natural chlorophyll is divided into two layers, the green layer has 4-10mm chlorophyll b layer, and the other blue layer is 2-6mm chlorophyll a layer.
(7) Put the part in the middle of the blue layer (about half of the blue layer) into the ether, filter and elute the suspension, wash it with distilled water, dry it with sodium sulfate, and filter it with a vessel to obtain chlorophyll a.
(8) Remove the middle part of the green layer in (6), quickly put it into the ether for filtration and elution, and make chlorophyll b ether solution.
2. Separation
Chromatography is an important method for separation, purification and identification of organic compounds, especially in microanalysis. Pigments in fruits and vegetables mainly include fat-soluble carotene, lutein, chlorophyll and water-soluble anthocyanins. In the extraction experiment, we can use the principle of similar phase solubility to filter out water-soluble anthocyanins, and then use thin layer chromatography, column chromatography, and high performance liquid chromatography to separate carotene, lutein, and chlorophyll. Because the polarity of these three pigments is weakened in turn, we can appropriately select a single organic solvent or a mixed solvent with different proportions as the developing agent and eluent, and determine the best separation conditions.
