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I need to dry some solvents like $\text{MeOH, EtOH, and DMSO} $ and I have to take care of purity of the solvents. These solvents are HPLC grade.

I am interested in freezing point and boiling point of these solvents with maximum error of $ \pm 0.5 C$, hence, I do not prefer to add silica gel (or other dehydrating agent) in the flask containing solvent.

What are other ways to dry solvents without putting something in them.

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    $\begingroup$ Drying is a form of purification. Why do suspect that 'putting something in' your solvent is going to disturb the purity beyond the current water content? Have you researched (ie search engine) purification methods for organic solvents? $\endgroup$
    – long
    Commented Jun 15, 2016 at 3:59
  • $\begingroup$ Then still add silica gel. It is not what you think it is. $\endgroup$ Commented Jun 15, 2016 at 4:52
  • $\begingroup$ My concern is, adding say silica gel may cause entry of other impurities in the solvent (some impurity present in the silica gel). $\endgroup$
    – ankit7540
    Commented Jun 15, 2016 at 5:33
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    $\begingroup$ Even distillation is becoming a yesteryear technology. Modern labs are moving towards low-hazard, efficient purification systems like Pure-Solv. A lot depends on the volume you need, but the key is to purify, via whatever route, immediately prior to use. $\endgroup$
    – long
    Commented Jun 15, 2016 at 6:02
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    $\begingroup$ Forget about the silica, use established protocols. Destill your alkanols. Boil methanol over magnesium, ethanol over sodium. Pre-dry DMSO over calcium sulfate or barium oxide, then decant and reflux/destill with calcium hydride at reduced pressure. $\endgroup$ Commented Jun 15, 2016 at 7:01

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There is actually a book on preparing laboratory chemicals you can look up:

"Purification of Laboratory Chemicals" by WLF Armarego and CLL Chai

However, given that all the chemicals you want to dry are extremely hygroscopic, I'm not sure how long they would stay super dry for calibration purposes (and I'm not sure you need super dry solvents for calibration either). If you need it to last, you may need a large dry box.

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I would suggest refractional destilation as a method to isolate your solvents from the impurities. You can also repeat this procedure until you have obtained a desired purity.

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