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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: lllhills on February 23, 2020, 09:22:12 PM

Title: Substitute for Petroleum Ether?
Post by: lllhills on February 23, 2020, 09:22:12 PM

I'm working on an extraction of caffeine from green tea. I'm referencing the procedures here:
http://employees.oneonta.edu/knauerbr/chem226/226expts/226_expt06_pro.pdf

Near the end of the procedure, it says to add Petroleum Ether to the solution. We may not have Petroleum Ether available, so I was wondering what alternatives I could used. I did some research, and found out that Cyclohexane may be a good alternative, but I wasn't sure if it would be safe to add to the solution that is created in the procedures, since we're going to be adding it while it's hot. If Cyclohexane doesn't work, what are some other alternatives I could possible use?

Title: Re: Substitute for Petroleum Ether?
Post by: clarkstill on February 24, 2020, 09:11:25 AM

Hexanes or cyclohexane would be reasonable substitutes for petroleum ether. The procedure seems to use it as an "antisolvent" - to help reduce the solubility of the caffeine in the organic (dichloromethane) solvent, so any non-polar organic hydrocarbon should do the trick.