BW please see the method I used in post #69 and the final results in post #71.

I never used EA or evaporated anything. It was acetone pulls without any prior defatting to which benzoic acid was added. After each addition of BA, the colour got whiter as is seen in post #71. I am sure a prior defat would have yielded a whiter product.

A thought I have re _Trip_'s larger crystals is that he left the acetone pulls for a few days (post #68 ) after which it would have picked up some water thereby increasing the solubility of bufo benzoate and leading to slower crystallization. Was your acetone dry before the extraction?

My acetone was dried beforehand and kept as dry as possible during extraction. After the pulls, it was dried again. The addition of BA immediately made small chunks of precipitate and after 20 minutes a sheet would cover the bottom of the dish.

I think adding water or not drying your acetone could lead to larger crystals, but may decrease yield. Should not be difficult to test I may give this a go.

I will have more chance to assay in a few week's time. Unfortunately, I think it will be very long before lab test results come in. Our postal system is very poorly run and packages take months to reach their destination, if they ever do. I will try to get hold of some TLC plates in the meantime to do qualitative analysis.