bp of mixed liquids to determine concentration??

Bumblebee · Mon Apr 04, 2005 7:45 am

I have a question...
I think i found a way to get some piperonal OTC from an compound that is used widely in cosmetics...
If I have a solution consisting of two liquids…. and the boiling points of the pure liquids are known:
1. Hydrocinnamic alcohol – bp: 236°C
and
2. Heliotropine (Piperonal) – bp: 263°C

i believe since the order in the INCI it ist more Heliotropine than Alcohol...
Since I don´t know how much % of them are in the solution, my question is: Is it possible to determine, by the mixed boiling point of the mixture, of how many percent heliotropine and therefore of how many % Hydrocinnamic alcohol it consists?

How is it possible to get the two separated? Fractional vac. distilling isn´t very useful since the to bp´s are to close together, and the column you will have to use has to have such a length that it would become impracticable….

What about oxidizing the cinnamic alcohol to cinnamic aldehyde? So the bp´s would be more different and an irie distillation can take place!

java · Consumer

This may come in handy in the dreaming as isipid bucket of drool over at WD referenced this helpful link, I thought it might be good to have it listed here as dreamers scrounge for information on the most current dream...........java

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Posted - Mar 15 2005 : 5:03:05 PM Show Profile Visit Insipid Bucket of Drool's Homepage Reply with Quote
K-mart.. ROTFLMAO.

Mixtures of liquids when distilled may reach a stage at which the composition of the liquid is the same as that of the vapour, this is known as an azeotropic mixture.

Heterogeneous mixtures do not have uniform composition and properties throughout, while heterogeneous equilibria involves substances that exist in more than one phases (i.e. gas and liquid).

Heterogeneous azeotrope refers more to the later, or simply put, a mixture that exists in more than one phase at a particular concentration and temperature while maintaining similar composition in both phases.

It is interesting to note that azeotropic boiling points are often much lower than the original boiling points of it's component substances.

http://www.chemeng.ed.ac.uk/people/jack/azeotrope/hetero.html
It's better to die on your feet, than live on your knees...............Emiliano Zapata (UH)
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Insipid Bucket of Drool
~Chairman of the Bored~

Posted - Mar 16 2005 : 1:50:22 PM Show Profile Visit Insipid Bucket of Drool's Homepage Reply with Quote
Don't forget homogeneous azeotropes, as SWIM will more commonly encounter these:

http://www.chemeng.ed.ac.uk/people/jack/azeotrope/access.html

capricorn · Mon Apr 04, 2005 8:46 pm

I think bisulfit addition could be quite practical here. Then you only get the bisulfite of the carbonyl compound and can hopefully separate them more easily. Then just convert back to the carbonyl.