The advantages and disadvantages of traditional heating reflux method and Soxhlet extraction method for extracting caffeine from tea were compared.

The advantages and disadvantages of traditional heating reflux method and Soxhlet extraction method for extracting caffeine from tea were compared: the reflux distance was longer and the extraction was more complete.

A common method of extracting compounds from solid substances by heating reflux extraction is to soak the solid with solvent for a long time to leach the required substances, that is, long-time leaching method. This method takes a long time, uses a lot of solvents and is inefficient. Soxhlet extractor is often used for laboratory extraction.

principle

Using the principle of solvent reflux and siphon, solid substances can be extracted with pure solvent every time, so the extraction efficiency is high. Before extraction, solid matter should be ground to increase the submerged area of liquid. Then put the solid matter into the filter paper sleeve and put it into the extraction chamber. Install the instrument.

When the solvent is heated and boiled, the steam rises through the air duct, condenses into liquid and drips into the extractor. When the liquid level exceeds the highest point of the siphon, the siphon phenomenon occurs, and the solution flows back into the flask, so some substances dissolved in the solvent can be extracted. In this way, the soluble substances in the solid are enriched into the flask by solvent reflux and siphon.