26 Jun 2008

Identifying residual solvents

Lab Experiment

Submitted by Joe Fritsch, Pepperdine University
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Description: 
Identifying residual solvents is important in helping students to interpret their NMR spectra and in the preparation of elemental analysis samples.  I have found the NMR work of Gottlieb and Nudelman to be valuable in my research and the teaching lab. The tabular data for many residual solvents in common NMR solvents for both proton and carbon spectra has been extremely valuable. Interpreting an NMR spectrum containing a residual solvent becomes  easier when the chemical shifts and multiplicity for the solvent are known. In addition, purification of such a sample can be aided by knowing the identity of the solvent and matching it to its volatility.
Equipment needs: 
NMR
Evaluation
Evaluation Results: 

My research students are readily able to use the tables of data to rule
out residual solvents in their NMR samples. Every time they collect a
spectrum they have Gottlieb with them and acknowledge which solvents
are in the sample when they bring the spectrum to me to discuss.

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Comments

Hi joe,

Thanks for pointing out that article!  It is quite useful.

Kurt 

Thanks for putting this one up-such a classic. Yet, how often does it get cited? It's taped to the wall in I don't know how many NMR labs. You just don't cite it, though. 

"An NMR sample of 1 showed that it was nearly pure, save for a small peak for residual solvent of crystallization and some stopcock grease.1"

And here's the updated version, Organometallics 2010, 29, 2176–2179. It includes a lot more "inorganic friendly" solvents and impurities more likely to be encountered by the inorganic chemist. 

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