Hello please advise on how to use Soxhlet's extractor exactly or some reference to the instructions I am dealing with extracting different plants in solvent alcohol or gasoline in advance Thank you for some advice Petr B.
Dear Mr. Peter,
Optical physicists say it is either very easy or, on the contrary, very difficult. The same can be said in extraction chemistry. The practice of enzymology at the Faculty of Science is the most difficult and expensive practitioner of the whole study and in large part is devoted to extraction. Many scientists have spent their life trying to extract and crystallize substances from plant and animal materials. On the other hand, simple extraction can be done easily by simply inserting the plant material into the solvent container. Such a procedure would be called batch extraction. In the case of quantitative extraction of 100% of the content of the substance, counter-current or charge-counter extraction can be used, as is used for example in leather tanning. Its description is indicated here .
From a practical point of view, the Soxhlet extractor stands somewhere on the border of the batch and column extraction. It is characterized by the recycling of the solvent, which takes place by distillation and re-condensation on the cooler over the charcoal cartridge. Some qualitative factors influencing extraction on the soxlethal have been described qualitatively in another answer , but I do not pay attention to the half-time mode in which the right Soxhlet works. The right Soxhlet has a tube that ensures that the cartridge is gradually filled with a condensing solvent and when it is completely filled, the drain tube is overheated and the contents of the cartridge are emptied into the warming flask. I could now refer you to resources that you would be able to study the extraction duration and its parameters. For these resources, you can make an idea of this for the practice of useless syllable "Chemical Engineering, Chapter Extraction" (see ), Freely available on the Internet. However, you would have to test the constants for the calculation experimentally.
So you do not avoid attempts (and mistakes), whether math or without it. If you want to extrapolate to the Americas, that is without mathematics, do the following: Let's say you have Soxhlet with a five-liter volume of the extraction vessel. Sprinkle into a patron about a kilo of plant material comminuted in grains of a maximum of 5mm (the seeds must be crushed even if they are like poppy seeds) or slices with a thickness of max. 3mm. Pour as much solvent as possible so that the material is overlapped, but do not turn the solvent into the bottom of the sox-bottle (you will need about four liters of solvent). Close Soxhlet and let it swell for a few hours at room temperature. Then add a little more solvent so that the bottling tube is overflowed and the solution flows into the lower container. The plant material should now be flushed and its volume should be increased. Drugs swell in different ways - wood only a few percent, about three times, some fruits even more than five times. It is in your interest to use that amount so the bulk drug will fill the cartridge about 90%. The drug usually absorbs a considerable amount of solvent, and therefore, the amount of the drug is much smaller than 4L. Now take a fresh dose of fresh solvent and pour the cartridge one more time just below the edge (now there is a drug in it, so the solvent will not fit any more). Allow two more hours to leach at room temperature, then turn on the extractor for low power (ie heating and cooler). When boiling in the bottom vessel, the condensing extract soon overflows the bottling tube so that the remainder of the solvent runs into the bottom vessel. Increase the extractor's performance to the working value (ie, the highest one at which it works smoothly), stay with it, watch the filling of the distillate and count the number of times it turns. When the extractor turns four times, extraction should be done roughly. This is the point in which most of the people do not pay to waste energy and to harass the drug by further heating to conquer the remaining about 3% of soluble substances remaining in the cake. You should now be the owner of between 2-7 liters of extract, to which more than 90% of the substances that can be obtained from the herbal drug by the solvent are transferred to the extraction.
Gasoline, of course, can not be used amateurally for extraction for food purposes. When extracting, be careful that the condenser really has condensed all of your solvents, and alcohol or even gas vapors have not escaped to the environment. Take personal care of the extraction and always use a sufficient amount of solvent to avoid the drying of the heating container. Always work with gasoline only outside in fresh air. Do not eat, drink alcohol or spirits in a larger quantity than small, do not smoke and do not handle with open fire. Legal Addition: I hereby waive any liability for damage to property and property caused by explosion of alcohol or gasoline.