[jbays1973]

Greetings:

First off I would like to say thank you to Scooby Snacks for the assistance with my question.  It was very clear and I was able to explain and demonstrate this to some of my co-workers who also had the question.  

Now I have a new question.  I am preparing to conduct some personal research on fatty acids from archaeological materials.  The procedure has a step where following the extraction of residues from the sample the extraction solvents are vaporized, and then the water removed to produce dry lipids.  This is where a problem comes.....the method uses an azeotropic mixture with Benzene to vaporize the remaining water with vaporized Benzene.  The organic chemist on my committee has said that this method is not widely used these days due to Benzene's flamability.  What other ways can I produce dry lipids once the extraction solvent is removed.  

By the way, following this dry lipids will be put into solution with methanol and HCl to yield methyl esters.  Can anyone help?

muchas gracias

[Mr Amino]

I use azeotropic evaporation of benzene to dry samples all the time.  It is common practice in organic chemistry.  However, benzene is used less nowadays because of its toxicity, not its flammability.  There are so many things that are highly flammable, i cant believe an organic chemist would say they dont use benzene due to its flammability.  You should use benzene if the method calls for it.