Extraction

In this book extraction is almost always about using an organic solvent such as benzene, DCM, ethyl ether (a.k.a. ether) and hex-ane to remove (extract) product (almost always in oil form) from an aqueous solution. The most basic way to extract is to pour the water solution into a PP container, add some solvent and stir the two as fast as possible for a few minutes. Most equipped labs use a large separatory funnel to shake the two liquids. When using a separatory funnel it is very important to vent the funnel as soon as the stopper is smacked into the top. This is done by immediately inverting the funnel so that the stopcock end is facing upward, opening the stopcock to release the pressure then closing the stopcock. The sep funnel is given a quick shake then vented again. This is repeated a couple more times after which the pressure production will have pretty much ceased. The rule is to then shake for 2 minutes and allow the layers to separate for 10 minutes. And which layer is going to which? Ether and benzene are always on top of water and DCM and hexane are always on the bottom.

Most science papers call for things to be extracted 3 times (3X) with a solvent. Strike feels that this is overkill and that one or two times is usually sufficient. Sometimes one has so much product oil that it forms its own heavy layer (usually at the bottom). There is no need to extract such a large amount with solvent. In such a case one would merely drain the oil from the water or, if using a PP container, decant the water from the oil. The water itself can then be extracted once with solvent and the solvent added to the oil.

Continue reading here: Washing

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  • hagos
    Where is ecstacy extracted from?
    4 years ago