Simple 1D processing in vnmr

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Revision as of 23:36, 3 March 2008 (edit) Sudipta Majumdar (Talk | contribs) (→Fine-tuning phasing) ← Previous diff		Revision as of 23:38, 3 March 2008 (edit) (undo) Sudipta Majumdar (Talk | contribs) (→Apply baseline correction) Next diff →
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	'''Main menu'''->'''DispMenu'''->'''Interactive'''		'''Main menu'''->'''DispMenu'''->'''Interactive'''
		+	Push second button from the left (it will be either '''Full Integral''', '''No Integral''' or '''Part Integral''')
	[[Category:vnmr tutorials]]		[[Category:vnmr tutorials]]

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Revision as of 23:38, 3 March 2008

Contents 1 Open file 2 Apply simple FT 3 Phase the spectrum 3.1 Autophasing 3.2 Manual phasing 3.3 Fine-tuning phasing 4 Apply baseline correction

Open file

Open file (type in vnmr command line):

rt('file_name')

rt - retrieve, file name does not have to have .fid attached

Apply simple FT

Apply simple processing:

ft f full vsadj

ft - apply Fourier tranform
f - show full 1D spectral window
full - stretch spectrum on full screen

Phase the spectrum

Autophasing

Try automatic phasing

aph

Manual phasing

If autophasing fails, you have to phase manually.

Click on Main Menu(top row of buttons)->DispMenu(bottom row of buttons->Interactive(bottom row)->Phase(bottom row)

Move cursor to the left part of spectrum, click and hold left mouse button.

Drag mouse up or down to make peaks in left part appear phased, release left mouse button.

Move cursor to the right part of spectrum click and hold right mouse button.Drag mouse up or down to make whole spectrum well phased.

Now hit Return(bottom row of buttons on the right)

If you still see huge baseline distortion - it is possible that phase parameters lp(left phase) and rp(right phase) are too large. You can check what they are by typing:

lp?
rp?

Normally they should not exceed ~360 (?)

If rp or lp are too large - reset them:

lp=0 rp=0

Then repeat manual phasing procedure shown above.

Fine-tuning phasing

This part is relevant if peaks that you want to phase are less intense then the major peaks in spectrum.

Adjust vs(vertical scale) so that you can see peaks of interest.

One way to do it is to type:

vs=vs*5

Here vs is multiplied by 5 (use other number if you want)

You might want to repeat above multiplication by scrolling up and pressing 'Enter' until you clearly see the low intensity peaks that need to be phased

Now repeat manual phasing procedure so that baseline around very intense peaks looks symmetric and low intensity signals are phased too.

Apply baseline correction

Main menu->DispMenu->Interactive

Push second button from the left (it will be either Full Integral, No Integral or Part Integral)