Principle of water extraction and alcohol precipitation

The principle of water extraction and alcohol precipitation method is as follows:

Water extraction and alcohol precipitation is an extraction method of traditional Chinese medicine, which is mainly used to remove impurities in traditional Chinese medicine and improve the clarity and purity of liquid medicine. The principle of this method is to use the solubility difference of different substances in ethanol and water and the precipitation of impurities by ethanol to achieve the purpose of separating and purifying drugs.

Specifically, the water extraction and alcohol precipitation method includes the following steps:

1, soaking

It takes several hours to several days to soak Chinese herbal medicine in water, depending on the kind of Chinese herbal medicine. In the process of soaking, the soluble components in Chinese herbal medicines will gradually dissolve in water.

Step 2 fry

Decoct the soaked Chinese herbal medicines in water for 1-2 hours. In the process of decoction, the soluble components in Chinese herbal medicines will be further dissolved in water, while impurities will gradually precipitate.

Step 3: Filter.

The boiled liquid medicine is filtered to remove solid impurities.

4, alcohol precipitation

Add a certain amount of ethanol to the filtered liquid medicine to mix the ethanol with water. The addition of ethanol will make the soluble components in the liquid medicine dissolve in ethanol, while the impurities will precipitate due to the decrease of solubility.

5, let stand

The liquid medicine after alcohol precipitation is allowed to stand for a period of time to fully precipitate impurities.

6. Pour out the supernatant

After standing, the supernatant was poured out to remove the impurities deposited below.

7. Recover ethanol

Distilling the dumped supernatant, and recovering the ethanol in it to obtain a more pure drug extract.

The advantage of water extraction and alcohol precipitation method is that it can effectively remove impurities from Chinese herbal medicines and improve the clarity and purity of liquid medicine. At the same time, this method is simple and low cost, so it is widely used in the extraction of traditional Chinese medicine. However, the water extraction and alcohol precipitation method also has some disadvantages, such as the possible loss of some effective components, and the precipitation method is not effective for some impurities with high polarity.

In a word, water extraction and alcohol precipitation are common methods for extracting traditional Chinese medicine, which can effectively remove impurities and improve the purity of liquid medicine. In actual operation, we should choose suitable operating conditions according to the nature and needs of different medicinal materials to achieve the best extraction effect. At the same time, with the development of science and technology and the emergence of new extraction technology, the application of water extraction and alcohol precipitation in the field of Chinese medicine extraction will be improved and perfected.