Fourier Transformation

1. Set fn='n' to zerofill your data set. Zero filling improves your digital resolution.
   
2. Set lb, gf, gfs, sb, and sbs to apodize your FID to improve signal/noise, resolution, or the shape of the peaks. Click on main menu, process, to interactively adjust these apodization parameters.
   
3. Type wft to fourier transform your FID into a spectrum. The spectrometer DC offset is automatically subtracted from the FID, the FID is apodized and zero filled.
   

Phasing the Spectrum

• Click on display and phase, adjust phase with mouse:
  • Move the mouse pointer over a peak and in the vertical center of the graphics window.
  • Click the left mouse button. A portion of the spectrum will turn blue between two vertical cursors, and a horizontal cursor will also appear.
  • With the mouse pointer between the vertical cursors, hold down the left mouse button (for coarse control) or right mouse button (for fine control) and slide the mouse to change rp, the zero-order phase parameter. Sliding the mouse pointer above the horizontal cursor increases rp (rotates peaks colckwise), and sliding the mouse below the horizontal cursor decreases rp (rotates peaks counter-clockwise). Release the mouse button when done.
  • Click the middle mouse button to adjust the vertical scale of the spectrum.
  • Move the mouse pointer outside the vertical cursors to another spectral region and click the left mouse button. The phase changes made in step III will be applied to the entire spectrum, and the new spectral region will turn blue.
  • Hold down a mouse button and slide the mouse to change lp, the first-order phase parameter.
  • To exit the phasing mode, click on any button from the menu, such as box.
• Type aph.
• Type rp=x and lp=y to set these phase correction parameters to the value of x and y. Type phase(x) to change the phase of all peaks by the value of x.
  

Setting the spectrum reference

1. Click on main menu, display, interactive. Position the cursors to the left and right of the reference peak. Click on expand.
2. Position the left cursor near the center of the reference peak and type nl.
3. Type rl(valuep) where value = the ppm value of the peak. For instance, type rl(7.26p) to reference the residual protonated chloroform peak to 7.26 ppm.

Baseline Correction

1. Type dc to apply a linear drift correction.
2. Type cz to clear the list of baseline points.
3. Type region to automatically create the list of baseline points.
4. Click on main menu, display, interactive, integral. If there are peaks that are not integrated (i.e., are not bisected by a yellow line), move the mouse pointer to the left of the peak, type z and type the <return> key, move the mouse pointer to the right of the peak, type z and type the <return> key.
5. Type bc to apply a baseline correction.
   

Integration

1. Type dc to apply a linear drift correction.
2. Type cz to clear the list of baseline points.
3. Type region to automatically create the list of baseline points.
4. Click on main menu, display, interactive, integral.
   • If there are peaks that are not integrated (i.e., are not bisected by a yellow line) move the mouse cursor to the left of the peak, type z and type the <return> key, move the mouse pointer to the right of the peak, type z and type the <return> key.
   • If there are integration regions with incorrect starting and ending points, click on main menu, display, interactive, integral, reset. Position the mouse pointer where a new integration limit should be set and click the left mouse button. Position the mouse pointer near an integration limit to be removed, and click the right mouse button.
5. Click on lvl/tlt and adjust the level and tilt of the integrals with the mouse buttons.
6. Type isadj to normalize the total integration to 100. Type ins=new# to change the integral normalization scale to the value of new#.
7. Type vp=12 dpirn to display integral values on the spectrum. Type dli to display a list of integrals.
   

Peak Picking