Extracting And Washing
Some people find these two important operations complex and confusing, when they are actually quite simple. You extract good substance from impure mixtures. You wash impurities from good material.
Solid — Liquid Extracting. This is not done too often, but if you have ever made tea or coffee you should be able to do this, as it is basically the same thing.
Liquid — Liquid Extracting. This requires a separatory funnel and two liquids (solutions) that must be insoluble in each other. The liquids must form two layers in the funnel or washing or extracting cannot be performed. Solids (crystals, etc.) need to be dissolved in a solvent, and that solvent must be insoluble in the extracting or washing liquid. Never throw away any layer until you are sure that it does not contain product.
Using The Funnel. Add the liquid to be extracted or washed to your funnel; if you forgot to close the valve your liquid is now on your shoes. Add the extractor or washer carefully to the mixture. Install the funnel stopper and invert so that the stem points to the roof; make sure one of your hands is holding the stopper securely inward. Most of these liquids fizz when mixed with the extractor, creating pressures that must be bled off through the valve as follows. Swirl or shake once very gently while still pointing the stem at the roof, then open the valve to bleed or "burp" the pressure. Close the valve and shake twice, then burp the funnel. Keep increasing the shaking between burps until you can shake the living hell out of the mixture for long periods, as this is the type of agitation necessary to extract or wash.
Continue reading here: Drying
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