Rotovap Question


#1

What temperature do I distill a winterized mixture at in in a rotovap. I’ve been going 70°C


#2

Distill in a rotovap? A rotovap purpose is to recover your solvent and leave the “goodness” back in the work flask.


#3

I do 50C


#4

Yeah, but that uses distillation as the method of separating. You distill off the alcohol, or so I thought.

Edit: back to post. It depends on your cooler and vac depth. You can go as high as 70c if you have the cooling capacity in the condenser. Otherwise it depends in how much your pump pulls at different temps. I go by what the condensation looks like in the condenser with how much etho drips out of the vac pump. I stay at 58c with vac at 20-40 torr.


#5

I do 70C


#6

I always thought spd as distillation. Rotovap as evaporation.

I do a 48c bath temp, -23hg vac pull, and 50-60 f h2o


#7

I typically run as hot and spin as fast as my chiller can handle. When I was doing more consulting I always found that clients were scared to turn up the heat and rotation. This can cost you valuable time during EtOH recovery that most labs just can’t afford. My recommendation is always to turn the temperature and rotation as fast as your chiller can handle.


#8

Depends on the compound your thinking of…because your distilling alcohol in the roto


#9

@PotHeadInASpaceSuit is right the process in a rotovap is distillation
Can t blame him :grinning:


#10

-10°c chiller, 30°c water bath


#11

Hi

I suggest that you could use spd that will be better.

I am manager terry from China manufacturer that has been specializing in producbig rotovap, chiller, spd, molecular distillation and so on.

If you could dm in this forum, the price will be still better.

Welcome your dm


#12

Hi

I am manager terry from China manufacturer that has been specializing in producbig rotovap, chiller, spd, molecular distillation and so on.

If you could dm in this forum, the price will be still better.

Welcome your dm and inquiry.


#13

It depends on what the final product will be. For distillate, 70-80°C can be done for maximizing effiency if your chiller can keep up. For isolate or shatters, the lower the temperature the better to minimize decarboxylation.


#14

It’s a distillation apparatus all it does that’s different is it spins out your mixture for faster recovery times and less residence time. None the less it still has all the parts of a regular distillation apparatus. A condenser, a boiling flask, a receiving flask, vacuum port, a water in and a water out -on the condenser- . Again all it does is spin it out.


#15

by spin it out, you mean thin it out right?

Thin film evaporator.

if spinning faster = a thicker film, it is not a win.

Correct velocity depends on viscosity.

If faster is always better, why can I turn it down?


#16

i usually do 68rpm to 89rpm @ 70C


#17

54C / 125 rmp


#18

I run at 85C, but to be honest that overwhelms the condenser and a good amount ends up in the cold trap. You know you are going too hot if the pump is shooting out alcohol haha