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Anonymous users2024-02-11Tomatoes contain lycopene and a small amount of B-carotene, both of which are carotenoids. Carotenoids are polyene pigments that are insoluble in water and soluble in fat-soluble organic solvents. In this experiment, the water in the tomato was removed with ethanol, and then the carotenoids were extracted with methylene chloride.
Because methylene chloride is not miscible with water, carotenoids can only be effectively extracted from tissues after water is removed. Depending on the polarity of lycopene and b-carotene, they can be separated by column chromatography. The separation effect can be tested with thin layer chromatography.
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Anonymous users2024-02-10The methods of extracting pigments are: extracting pigments and grinding, preparing filter paper strips, and drawing filtrate lines: uniform, straight, fine, and repeat several times.
In addition to this, there are:
Separation of pigments: Do not allow filtrate lines to touch the chromatography.
Observation and recording: The results on the filter strip from top to bottom are: orange-yellow (carotene), yellow (lutein), blue-green (chlorophyll a), yellow-green (chlorophyll b).
The experimental principle is as follows:
The pigments in chloroplasts can be dissolved in organic solvents acetone or absolute ethanol to extract pigments.
The solubility of each pigment in the chromatography solution is different, and the pigment is separated with the different diffusion rate of the chromatography solution on the filter paper.
The tips are as follows: 1. What are the requirements for blades? Why do you want to remove the petioles and thick time lines?
Green, preferably dark green. Because petioles and veins contain very little pigment.
2. What is the role of silica? What is the effect of not adding silica on the experiment?
In order to make the grinding sufficient. Without the addition of silica, the color of the filtrate and pigment band will be lightened.
3. What is the role of acetone? What can it be used instead? Can it be replaced with water?
Dissolves pigments. It can be replaced with organic solvents such as alcohol, but not with water because the pigment is insoluble in water.
4. What is the role of calcium carbonate? What is the effect of not adding calcium carbonate on the experiment?
Protects the pigment from damage to the pigment in the chloroplast during grinding. Without the addition of calcium carbonate, the filtrate will turn yellow-green or brown.
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Anonymous users2024-02-09Ingredients needed to extract the pigment of steamed vegetables: rice dumplings, vegetables or vegetable leaves, water, cups.
Step 1: Prepare to call your friend a clean scoop.
Step 2: Place the vegetables or leaves of the vegetable pigment to be extracted in the nest, here the leaves are selected.
Step 3: Lick the leaves vigorously and continuously.
Step 4: Pour in a small amount of water when the leaves are paste.
Step 5: Continue to lick, at this time you can clearly see that the water has turned green.
Step 6: Pour out the juice of the cabbage leaves and kernels in a cup.
Step 7: Depending on the amount of water, the shade of pigment varies. The pigment of the vegetable is extracted.
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Anonymous users2024-02-08Pigment extraction method steps:
1. Materials: spinach leaves, calcium carbonate, ethanol, silicon dioxide, mortar;
2. Select leaves: choose fresh and tender spinach leaves, and the amount should not be too much or too little, too much is not easy to grind, too little is too little pigment;
3. Grinding: When grinding, you should pay attention to cutting the leaves into the grinding first, and you must also add an appropriate amount of silica, ethanol and calcium carbonate before grinding;
4. Filtration: Choose a single-layer nylon cloth when filtering, and do not choose filter paper, because the filter paper has small holes and strong adsorption capacity;
5. Making filter paper strips: When making filter paper strips, you must cut off the two corners of one end, and draw a thin line of lead in the pen near the end of the cut corner, which must be thin and straight;
6. Draw a fine line of filtrate: use a capillary straw to draw a line along the thin line on the filter paper strip, and the filtrate must not diffuse; Sold no.
7. Separation of pigments: put the filter paper strip just drawn into the chromatography solution;
8. Drying the filter paper strip: After a period of time, Jiankai takes out the filter paper strip, and through drying, the pigment band on the filter paper strip can be observed after a period of time.
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Anonymous users2024-02-07The principle of pigment extraction: pigments can be dissolved in organic solvents. It is extracted with organic solvents, and then stuffed and then filtered, concentrated under reduced pressure, vacuum dried and refined to obtain the final product.
The solvents used to extract pigments have different choices according to the properties of pigments and the raw materials used, such as water, acid and alkali solutions, and solutions such as ethanol, acetone, alkanes, benzene, etc., oils and carbon dioxide.
Because the solubility of different pigments in organic solvents is different, the solubility of different pigments in the chromatography solution is larger, and the chromatography rises faster, so the four pigments will be separated.
According to chemical properties, chlorophyll is an ester of chlorophyllin, under the action of alkali, it can make its ester bond saponified to generate chlorophyllin salt, which can be soluble in water, but because it retains the structure of mg nucleus, it still retains its original green color.
Among the carotenoids, carotene is an unsaturated hydrocarbon, - carotene hydrolysis can produce 2 molecules of vitamin A, lutein is a diol derived from carotene, can not undergo saponification reaction with alkali, according to this, chlorophyll and carotenoids can be separated.
The principle of pigment extraction in chloroplast is: because the photosynthetic pigment is located on the sac-like structure in the chloroplast, in order to extract it, it is necessary to destroy the leaf epidermis, cell wall, cell membrane, and chloroplast double membrane, so it should be cut and crushed with silica to grind in order to fully extract the pigment. >>>More
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