Locking and Shimming

Here we look at some of the ways we try to maximize the power of NMR, in processes called locking and shimming.

[@AlphaNumeric123]

Absolutely fantastic teacher. He strikes the balance between making something accessible and--importantly--intuitive while also not watering things down too much or simplifying to the point of distortion. Really has the touch of a professor as opposed to a KZbin educator, which I mean as a compliment. Sub'ed and look forward to looking at more content!

[@Brsawesome]

Hi Jeff, great explanation. Only 400 MHz, is 400 million Hertz (rather than 400 billion Hertz). Keep up the good work!

[@seamus9898]

awesome! best video I've found on lock & shim

[@vanfidel]

Great explanations, thanks. Cracked me up how disgusted you looked about it looking like a UV spectrum.

[@RohitPant04]

Well done, Jeff. This was well presented!

[@ramjayakumarv9934]

Great explanation sir. Thank You.

[@enzolong9085]

Really cannot thank you enough for this explanation sir. Bless you

[@matiafossatti9091]

Great explanation, many thanks, prof. Jeff.

[@jefforvis461]

Thank you, I appreciate it.

[@Pepsimaximo1]

Great explanation, thank you

[@aag7274]

very helpful thanks Jeff

[@alcevallo4631]

Thanks!

[@nowar6697]

Very well explained Jeff Orvis, i think it is 4bn instead of 400bn. lovely lecture

[@JustinKoenigSilica]

400MHz is 400 million...

[@Phosphoenol_pyruvate_CK]

Hi. Please I am wondering how long does it take to acquire a spectra from a sample on standard NMR machines?

[@jefforvis461]

The answer is ... it depends. A standard proton spectrum of a reasonably concentrated sample can be acquired in under a minute. A highly dilute sample that requires over 100 scans can take five minutes. If one were to do a whole suite of experiments on a sample (proton, carbon, DEPT, COSY and so on) at least an hour of time is usually required. The longest experiments we typically see are carbon spectra of samples that have a low solubility in any common deuterated solvent. Those can be overnight runs of thousands of scans to get well defined peaks and a reasonable signal to noise ratio. I hope this helps.

[@Phosphoenol_pyruvate_CK]

Thank you