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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: lespaul on January 10, 2013, 03:38:51 PM

Title: Does ethyl acetate dissolve plastic test tubes?
Post by: lespaul on January 10, 2013, 03:38:51 PM
Does anyone know if ethyl acetate dissolves plastic? namely the plastic in small test tubes (clear)? (ideally glass would be better, but we dont have in stock)

Im running an analysis and need to partition the phases using ethyl acetate. I would hate for the EA to dissolve the plastic and throw off my results. The concentration of EA will be less than 5% with 95% water.

Thanks

Title: Re: Does ethyl acetate dissolve plastic test tubes?
Post by: Dan on January 10, 2013, 04:14:18 PM
It might do, depends on what type of plastic it is. I have seen organic-soluble test tubes before. They were given away to us for free, which we thought was a good deal until we discovered they were soluble in most of the organic solvents we had to hand. Fill one with EtOAc and see what happens.

Title: Re: Does ethyl acetate dissolve plastic test tubes?
Post by: lespaul on January 10, 2013, 04:52:49 PM
Hi Dan, thanks so much!! I placed an order for glass just in case.
Title: Re: Does ethyl acetate dissolve plastic test tubes?
Post by: curiouscat on January 10, 2013, 05:25:03 PM
The concentration of EA will be less than 5% with 95% water.

I'd agree with Dan on this. Except at 5% levels my gut feeling says you'll be fine.

If you do test, I'd be curious to hear.
Title: Re: Does ethyl acetate dissolve plastic test tubes?
Post by: Dan on January 10, 2013, 06:24:28 PM
Except at 5% levels my gut feeling says you'll be fine.

Is it actually possible to dissolve EtOAc in water at a concentration of 5%? 19:1 water/EtOAc is surely biphasic, and where the organic layer contacts the plastic you may have problems.
Title: Re: Does ethyl acetate dissolve plastic test tubes?
Post by: curiouscat on January 10, 2013, 11:27:21 PM
Is it actually possible to dissolve EtOAc in water at a concentration of 5%? 19:1 water/EtOAc is surely biphasic,

Wikipedia reports a Solubility in H2O as 8.3 g/100 mL. That should mean it isn't biphasic. Right?

Or am I mistaking some concept?  :-\

Title: Re: Does ethyl acetate dissolve plastic test tubes?
Post by: Dan on January 11, 2013, 03:14:05 AM
I had no idea it was that soluble, my mistake.
Title: Re: Does ethyl acetate dissolve plastic test tubes?
Post by: curiouscat on January 11, 2013, 03:42:15 AM
I had no idea it was that soluble, my mistake.

Maybe not a mistake. Something's fishy.

e.g. This chart from Sigma Aldrich lists H2O-EtOH as immiscible:

(http://www.sigmaaldrich.com/content/dam/sigma-aldrich/research-essentials/solvents/migrationsolvents1/ethyl_acetate_miscibility.gif)