• Members of the previous forum can retrieve their temporary password here, (login and check your PM).

Tried to purify my spice, not sure about results

Migrated topic.

nigl

Rising Star
So I had some freeze precipitated yellow-lightbrown spice which I wanted to purify and crystallize.

About 1.8g of the product were placed in an erlenmeyer and with 50ml Naphtha (Pentanes, Hexanes, Heptanes) and put on the waterbath at approx. 60 °C. The solution was stirred until more and more yellow product was solved in the liquid. A brown goo didn't go in solution and was filtered off (the filter was washed before with hot naphtha too prevent the product precipitating in the filter). A yellow clear solution was obtained. The dark goo in the previous flask was washed with 20ml hot naphtha again and the combined naphtha solutions were put in a crystallizing dish.

Now I know this is technically not recrystallizing but after letting the solution sit overnight at room temperature there were some very nice 2-4mm crystals visible and also some 1mm diameter orange drops. When all the naphtha has evaporated and only crystals and drops are left I could simply carefully take the crystals and wipe the orange oil with paper. I can't get all of the oil but after that I can do a real recrystallizing step when I have much less oil so that it won't precipitate like it did this time but rather stay in solution.

What do you guys think?
 
It's a good idea to let it slowly cool to room temp before putting it in the freezer! The slower the cooling, the larger and purer are the crystals. You can avoid the freezer altogether and grow large crystals by slow evaporation.

However, filtering is the wrong method here, it's not the way to separate fluids. Did you decant the naphta from the brown goo? Or did you just filter out dust, hairs etc?
 
Back
Top Bottom