Liquid-solid extraction is to use the solvent to achieve the purpose of extraction and separation by using the solvent to have high solubility for the required components in the solid mixture and low solubility for impurities. One method is to soak the solid material in the solvent for a long time to achieve the purpose of extraction, but This method takes a long time, consumes solvent, and the extraction efficiency is not high. The other is the method of Soxhlet extractor, which uses the principle of solvent reflux and siphon to continuously extract the required components in the solid mixture. When extracting When the liquid level of the solvent under reflux in the cylinder exceeds the siphon of the Soxhlet extractor, the solvent in the extraction cylinder flows back into the round-bottomed flask, and siphon occurs. As the temperature rises, the reflux starts again, and the solid matter can be Extracted by pure hot solvent, the solvent is reused, shortening the extraction time, so the extraction efficiency is higher
The Soxhlet extractor is composed of an extraction bottle, an extraction tube, and a condenser. There are siphon and connecting pipes on both sides of the extraction tube. The joints of all parts should be tight and not leaking. When extracting, wrap the sample to be tested in a defatted filter paper bag and put it into the extraction tube. Petroleum ether is added to the extraction bottle, the extraction bottle is heated, the petroleum ether is vaporized, and it rises from the connecting pipe into the condenser, and the condensed liquid drops into the extraction pipe to extract the lipids in the sample. When the petroleum ether liquid level in the extraction tube reaches a certain height, the petroleum ether dissolved in crude fat flows into the extraction bottle through the siphon. The petroleum ether flowing into the extraction bottle will continue to be heated to vaporize, rise, condense, and drip into the extraction tube, and so on, until the extraction is complete.