What’s this sugar-like substance precipitating from my CO2 oil?
I recently started clarifying my winterized/fat-filtered CO2 oil with activated carbon. I have since been finding a sugary precipitate that is first noticeable on the flask of my roto-evaporator (see photo). Where it really becomes noticeable is at the bottom of my beaker or roto-flask after sitting for a few days under vacuum to purge out the last bit of ethanol (see photo of it stuck to the roto-flask). Is this sugar…or?
Some details of my procedure:
I mix 10:1 EtOH:oil with activated carbon at approximately 9g carbon powder per liter of EtOH:oil mixture. This is done at 43C.
I pour a silica/ethanol slurry into a Hochstrom over a 1um filter paper and pull vacuum! to remove the carbon. I then rotavape and purge in a vac oven.
Before using carbon, I’ve never seen this stuff. I’ve been able to remove it from the oil by decanting the oil off of the beaker/flask; the sugary stuff sticks pretty firmly to the bottom (see photo of it stuck to the roto-flask) and I’m able to resuspend in ethanol and collect it onto a 1um filter paper (see photo). I’m pretty certain that it’s not silica because (1) it looks different and (2) a colleague of mine is using the same carbon filtration procedure without silica and finding the same stuff.
Any ideas would be helpful. We are making carts with this oil and I’d love to know whether it’s necessary to remove this stuff versus just mixing it back in.