These directions assume you have tuned but NOT locked and shimmed on the sample.  If you need more information on these procedure then see the detailed sections for running a ¹H spectra.
 

Commands to type in XWINNMR:

ej and then ij to insert sample.
rsh 5mm.tbi."solvent abbreviation"  or type rsh  to see a list of solvents.
lock "solvent abbreviation" or type lock  to see a list of solvents.
rpar "parameter set name" or type rpar  to see a list of parameters.  Try the wfu_ files first.
eda and then change: (note that the ns, sw, o1p, td and si can be entered by typing the command in lower case then a space then the value)

1. PROSOL (scroll down about 1/2 way to find) to TRUE and right above this item change to your solvent.
2. NS to desired number of scans
3. SW to desired sweep width.  Find with:    max ppm - min ppm = sw
4. O1P to desired center of sweep width.  Find with:  (0.5*sw)  + min ppm = O1P
5. TD to the desired number of points to sample the FID (if TD is changed then make sure to type si  and set the value to 0.5*TD.  Standard 1D 1H spectra are collected with td = 64k, si = 32k with sw = 20 ppm and o1p = 9ppm.
6. For 2-D experiments you will need to consider the F1 and F2 dimensions.

expt will return with the estimated time for the experiment.

Note on changes to SW, TD and NS:  You must always balance resolution and time constraints with signal-to-noise using TD, SW and NS. One can increase the resolution by increasing TD and keeping SW constant or one can keep TD constant and decrease SW.  The former keeps the ppm range the same whereas the latter narrows the ppm range and is most commonly encountered.  So for instance if you decrease SW by 1/2 then you can decrease TD by 1/2 and keep the same resolution and total experiment time as you had before.  Lastly, one can sacrifice resolution by decreasing TD for an increase in signal-to-noise by increasing NS.  For example, with a dilute sample one can decrease TD by 1/2 and increase NS by 2, so one has increased the signal-to-noise ratio at the expense of resolution.  The here is "If you want good signal-to-noise ratios and resolution on dilute spins then time must be available."

Shim your sample by any of the following methods:

1. Manually using the bsmsdisp
2. Manually using the BOSS keyboard
3. Automatically using an autotune procedure by typing tune and clicking on "example bsms"
4. Automatically using gradient shimming (recommended for aqueous samples).  Make sure sample is NOT spinning, type ro to start or stop spinning. Type wsh GSHM y wait a few seconds then type gradshim.  Make sure the drive is x and the user is your account name.  Click on Start Gradient Shimming.  Click OK once the lock stabilizes. For the best results repeat the entire procedure or autoshim with the tune command.

rga resets the gain
a take to the acquisition window
zg starts the run
When finished type ef to apply the exponential window function and transform the data.
apk to automatically phase or manually phase as described in the XWINNMR document.
manually integrate the spectra
pscal preg to scale all peaks to the largest in the defined plot region
cy 10 to make the tallest peak in the plot region 10 cm tall.  A value of 0 will scale as displayed in the screen.
setmi to set threshold for peak picking.  Make sure the y-axis units are cm, change by clicking the YU button on the left panel of buttons.
To print ppm or Hz values for peaks type these commands or use the edg window:

plabels yes so peaks will be printed (use no to turn off)
plunit Hz so peaks are printed in Hz (can also use ppm) [found in the edplabels item]
plcolor blue to make peak labels easier to see in preview (black and red are acceptable) [found in the edplabels item]

expand region then type dpl1 and return to all questions
view to preview of your spectra as it will be plotted
plot to send preview to plotter

If you want to run another experiment on the same sample type iexpno to increment the experiment number the experiment number while keeping the same file name.

 

Back to NMR page | Back to Department page