Gojoe wrote:So my question is, if I break up the 500 ml pulls, do I still put the full 500mls in the same Mason jar for freezing? Separate jars? If you wait 3 hours between pulls as the Tek recommends, won't some initial solution evaporate before the second and third pulls?
500 ml seems way too much even for that amount you mentioned. You can do more smaller pulls.
No it won't evaporate as long as you keep it in closed container - naphtha or heptane don't evaporate that quickly even if left on air at room temp.
I would not go for 1 lb of bark for starters. Extract something like 50 g first and learn how that works, then scale up slowly.
However, note that we don't discuss large scale operations here.
Gojoe wrote:And once the 500mls is pulled and multiple extractions are done from it, is the base solution now waste product? Or can more NaOH be added for more pulls?
Yes and no.
There is a certain amount of alkaloids in the plant. Adding enough base will convert say 99.95% of them to a free base soluble in the extraction solvent. The first pull will remove say 75% of them, second pull 15%, third pull 3% and so on.
Adding more base and doing more pulls will give little bit more alkaloids, but the returns are quickly diminishing to amounts next to nothing. It's basically scraping the last specks from the bottom of the plate.
Three pulls are usually enough to get most of the alkaloids. Further pulls does no usually worth it.
Depending on the amount of solvent and solution, you may need more pulls, but that depends on several factors - look up A/B extraction or liquid-liquid extraction in any chemistry articles to learn how that works.