Sonicator yielding less than standard A/B

[lethalbacon]

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?

 

[Hailstorm]

Once you have extracted DMT using your sonicator, do not discard the bark - process it using the normal A/B and measure how much product you had left behind. That can help narrow the problem down.

If the sonicator does not lyze the bark well, perhaps you'll have to heat the acidic solution up and/or run the sonicator for longer.