Swims been doing stb on pre-powered bark with great results. The solvent in his current extraction was brown instead of the usual piss yellow, so he plans to do a "mini a/b" on the collected solvent in hopes for some clean spice. 200 mL of solvent is collected. Does he add the solvent to acidified water, and then basify it? He's also not to sure about volume to be using..

SWIY could probably just salt it out with vinegar then separate evaporate the until it no longer smell of vinegar. (all explain in detailed in Q21Q21's tek)

Hopefully the brown is not micro-emulsions of lye-bark or other alkaloids, if it isn't the resultant product will be from yellow to brownish-yellow and be pure freebase spice which could be redissolved in naptha and recrystallized or made into a vinegar tincture. SWIM's recent test found no difference between smoking 20mg of solid crystallized freebase DMT and 20mg of gooey DMT freebase evaporated from a tincture.

If the resultant product is very brown then basifying again and pulling with naptha would be the best bet to make sure of the purity.

Good luck!

Did the salt step. Got some tan water and it's evaporating now. Can swim go straight to heptane re-x or does he need to clean with sodium carbonate to clean it up first?

If the naptha is brown at all, sodium carbonate, if its yellow or clear then straight to heptane will likely be fine, though you could do a wash anyway

just make sure to add the sodium carbonate to the water before adding it too the naptha or they could be some loss.