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  PROCESSING YOUR DATA
 

Operations on the NMR spectrum.

Whether you imported transformed and phased data, or did the processing yourself, at this point, you should have a pattern that resembles an NMR spectrum. It may have some residual twist in the baseline. The operations performed on transformed data will remove any remaining baseline distortions, find the chemical-shift positions accurately, and measure the peak areas.

To learn about the basics of spectrum processing (independent of software used), click here.

To access help with a specific NUTS operation, click here.
       
  Phase corrections
 

Due to instrument limitations, the spectrometer cannot begin acquiring data immediately after the rf pulse. Because of this slight delay, each component of the FID will be at a slightly different point in its oscillation when data acquisition is initiated. After Fourier transformation, these variations cause "twists" in the baseline that must be corrected.
   
  To perform phase corrections in NUTS, identify the largest peak in the spectrum. Left-click and line up the crosshairs (purple lines) over the selected peak, as shown below (click here for a larger version). Type p while holding down the mouse button. This selects the pivot point, at which the zero-order correction will be done.
 
   
  To complete the phasing routine in NUTS, type ph to enter. The appearance of the spectrum may change; this can allow it to be redrawn faster during the phasing procedure. Place your mouse over the following figure to compare the Base Level and Phase Level (click here for larger version):
 
   
  Left-click the mouse and move it right and left (for coarse adjustment) or up and down (for fine control) until the baseline on either side of the pivot peak becomes symmetric; this is called a zero-order correction. Observe this process in the spectra below by moving your mouse over the image (click here for larger versions). During this procedure, some peaks may decrease in size or even seem to disappear; they will reappear when you return to the Base Level.
 
   
  Right-click the mouse and move it right and left (for coarse adjustment) or up and down (for fine control) until the baseline becomes even, as demonstrated below (click here for a larger version). This is the first-order correction. Press the return key to go back to the Base Level.