Hey guys, figured I'd post this in the advanced chemistry section given that the average forum user does not have access to sonicators. Hope you can give me some insight.
I have a batch of bark that I can consistently get 1.3% yields out of, but with a sonicator I'm struggling to break 0.6%. My procedure is as follows:
-Add 150g powdered MHRB to 500ml acidic solution, ~3.5pH
-Sonicate using 500w sonicator and 1/2" probe for 15 minutes
-Vacuum filter, rinse with 100ml water and filter again
-Repeat first three steps and combine, as my separatory funnel holds ~1300ml
-Basify using NaOH to ~12pH, heat to 60 degrees C to speed up separation of solvent
-5 30ml pulls with naphtha and freeze precipitate, testing shows no additional alkaloids available after 5 pulls.
Since I haven't had any issues with emulsions, I have replaced the "turning flask end over end" method with an overhead stirrer, which runs continuously for 5 minutes per pull. Given that after 5 pulls yields don't increase, I don't think this is the issue. The only other thing I can think of would be that I may need to add a stirplate to the sonicator.
Anyone want to chime in on what I'm doing wrong?