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Question & Answers About Roto Evaporator

2018-05-09 16:54:00
Summary :We have discussed many topics about roto evaporator in previous article, today we would like to sum up some typical questions from the Internet about rotary flask evaporator, and list several recommend answers for your reference.

We have discussed many topics about roto evaporator in previous article, for instance, how to use a roto evaporator, how to install a rotary flask evaporator, how to maintain a rotary flask evaporator, and roto evaporator cannabis extraction method, etc.. Today we would like to sum up some typical questions from the Internet about rotary flask evaporator, and list several recommended answers for your reference.

rotary flask evaporator

roto evaporator

Question: How do I evaporate water and ethanol using a roto evaporator?

Background: I found my rotary flask evaporator was very slow(4 hours to evaporate 500mL solution) when I’m trying to evaporate ethanol and water, which also contain milk protein. How can I optimise the rotary flask evaporator?

Answer A: You could shift the temperature for quicker evaporation. However, since you have casein rich proteins in the solution, it doesn't seem wierd at all that you take all that time to evaporate the solution (loads of hydrogen bonding!). Beware, however, not to denaturate your protein (if it is indeed your goal!) by increasing the temperature.

Answer B: I would like to recommend a vacuum pump to further lower pressure and offering high pumping capacity. Even without elevating temperature all the solution can be evaporated. Pump it with a vacuum pump which can attain pressure lower than vapour pressure of the solution which you want to evaporate.

Answer C: First you need to determine the percentage of the ethanol inside. After several time, the composition left in the flask will be different; so that you might adding 5 more degree from the boiling point of the mixture.

Question: Are there alternatives to Nitrogen drying for evaporating chloroform from lipids?

Background: I am following a protocol for extracting lipids from liver tissue for a cholesterol assay. The protocol calls for adding a 2:1 chloroform:methanol mixture, homogenizing, and rotating at 4C overnight. The next day, KH2PO4 is added and the mixture is split into three phases. The lower phase contains the lipids as well as chloroform, which must then be evaporated by drying in a stream of nitrogen.

I do not have access to inert gas, so I was looking for an alternative to this step. I read somewhere that an air stream can be used if butylated hydroxytoluene is added to prevent oxidation. I don't have access to a speed vac either. Could I just evaporate the chloroform in the hood for a few hours without compromising the samples?

Answer A: A roto evaporator could solve your problem(40°C maximum temperature of the bath).

Answer B: If you are going to measure only cholesterol, you don't need a speedvac, rotary flask evaporator or even nitrogen stream. Just add 0.1% of butyl hydroxytoluene to your samples, and let them evaporate overnight in a fume hood. It works perfectly, and the samples will not suffer. But you can do that if you are planning to quantify cholesterol only. Do not even bother to measure fatty acids, phospholipid composition or other lipid species. It won't work.

Answer C: Even if you don't have a SpeedVac or roto evaporator, you can simply use a regular vacuum pump to strip off the solvent. What you need is a clean rubber hose , a vent and a glass trap immersed in ice cold water

Above information is collected from Internet, please inform us if anything relates to infringement. If you are in need of roto evaporator or vacuum pump, please kindly send your inquiry to

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