Hey guys,
Just had a few quick qs about recrystallisation.
When SWIM had finished his most recent STB on 300g of Mimosa he was left with: fluffy white 'crystal powder' and some fluffy powder with an orangeish tint.
It totalled 2.7g suggesting it was quite impure because it's an unachievable yield. It's important to note that in previous times SWIM had been smoking this white powder, thinking it was pure, because the yield had been approx 0.4 or so percent of the bark total.
SWIM now realises that his technique sucked and is very glad he's sorted out the waste.
---> Anyway.
SWIM recrystalised and the following happened... When the hot naphtha was added to the powder, most of it dissolved fine, but he was left with some stubborn yellowy, sticky substance that wouldn't dissolve. SWIM was able to pour off the naphtha, leaving this substance behind in the jar (he collected it later and examined it, it seemed a bit crystally but there wasn't enough to refine it further).
SWIM then carried on with the freeze precip and has been left with translucent crystals.
----> The weight of this is 1.5g which seems ok, particularly given he lost 50ml of the first pull of naphtha on one of the 100g.
What I would like to know (on behalf of SWIM) is:
- Was it ok to just pour off the naphtha, was that all the impurities from the first product? It was too clumpy to be sucked up with a pipette. This seems to go against Noman's suggestion that you would have crystals on top of slag at the end of the recrystalisation.
- Is 50% of the product a normal amount to lose? Does this show SWIM had a lot of Sodium Hydroxide in his first product. (If so then this may explain SWIM's problems dosing off previous extractions that he thought were good but may well have been 50% impurities).
- Why is the first substance fluffy white powder and then the final clear crystals, is the whiteness literally brought by the NaOH?
- Can translucent crystals still be very impure or is this a sign of purity.
Any thoughts appreciated.