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Hello,

My 1H MAS NMR spectrum comes out with the right spinning side band pointing up and the left one pointing down. Does anyone know what that means?

I am running NMR on a hydroxylated metal oxide material. I use 3us pulse width, 5 sec acquisition time, and my sweep width is 100kHz. Also, I am using a 600 MHz Varian magnet, 5mm rotor, and spinning at 10kHz.

Thank you very much

asked Dec 16 '10 at 07:56

NMRUser61581's gravatar image

NMRUser61581
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updated Dec 16 '10 at 09:57

Evgeny%20Fadeev's gravatar image

Evgeny Fadeev
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Hello, you can post a picture too, if you like. - Evgeny Fadeev (Dec 16 '10 at 10:19)


2 Answers:
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Are these really sidebands, is there only one pair? If so, slow vrot to see if you can get a better sideband manifold and see if these additional sideband pairs also behave in this way. This sounds strange, maybe this is not a true sideband. Make sure by changing vrot.

link

answered Dec 30 '10 at 13:19

bernie%20o%27hare's gravatar image

bernie o'hare
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I am pretty sure that these are side bands because 1) they are symmetrically located around the main peak and 2)they are ~20 kHz apart, matching the ~10 kHz spinning speed. I will try my experiment at a slower spinning speed and see what happens. - NMRUser61581 (Jan 03 '11 at 10:04)

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It would be great if you could post a picture of the spectrum, that might help us identify what's going on. I will say that sometimes sidebands can invert if you're left-shifting your spectrum too much (this adds phase across frequency space in the fourier transform). This is usually not perfectly 180 degrees different though. What are your processing parameters?

link

answered Dec 17 '10 at 15:05

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vanderwaal
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