Tuesday 20 November 2012

Problems finding 99% ethanol/isopropanol

Something as simple as adding salt  can separate  phases.  








In Canada it's hard to find cool stuff...plain and simple. You can't buy liquid nitrogen or dry ice from ice cream stores like in the states, and it's more difficult to find concentrated alcohols at the local pharmacy (the max I've seen is about 70%), but for the sake of this project there is a way to get around it, and all you need is your standard rubbing alcohol, non-iodized salt and a clean glass jar. Salting out is a well known method for extracting and concentrating organic molecules like protein purification, but this can be applied to isopropanol and ethanol as well. Just pour your diluted alcohol mixture into a clean glass jar, pour salt (how much depends on the amount of water present in your diluted alcohol solution). the salt molecules have more affinity for water than organic molecules since they are very polar in terms of charge distribution. The salt sort of kicks out the alcohol into its own phase where the alcohol will float to the top and then you can take the layer with a turkey baster and there you'll have 99.9% pure alcohol! But if you can get your hands on something with 99% purity, it's probably better.

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