I'm not quite sure how or why this happened, but for some reason the convention for base to use for acid/base extraction is to use NaOH... why? For ghetto chemists, there needs to be a simple way to get the pH right so that the extraction goes properly and you don't extract other things because you raised the pH too high (ie 13+)
sodium carbonate and calcium hydroxide both produce a pH of around 12, which is sufficient yet within two pH points of the pKa of most simple monoamine alkaloids, such as methamphetamine, dmt, psilocin, mdma etc etc.
sodium carbonate is simple enough to use but can be a problem if there is something that prompts the carbonates to form back into carbon dioxide (eg, from a reaction mixture perhaps?) but on the other hand if one took hydrated lime and used it for a base, you would have to first dissolve it in water and settle out any calcium carbonate that probably will be present in domestic 'hydrated lime' as well as the excess from overshooting the right quantity... it only dissolves to the extent of 0.18 g/100 mL but at that rate of dissolution the pH is raised to 12ish... that works out to 1.8g per L to change the pH to 12... 1/4 of a teaspoon.
anyway, could somebee more wise than me explain why one wouldn't want to use sodium carbonate or calcium hydroxide as a base for acid/base extraction? thanks
oh... just remembered - clear ammonia, of course only raises the pH to 12ish as well... What are the criteria for selecting an extraction solvent?
I was thinking that maybe a different base that forms an insoluble salt with some undesirable material in the extract might be helpful in reducing the garbage that comes across into the nonpolar solvent (eg, tannic acid(s), which precipitate in calcium (?) i can't recall if that's correct, i know that lead ions precipitate it too though)