Routine Processing of a ¹H Spectrum

With the default configuration, seeing the FID after opening a spectrum means that the spectrum has never been processed with iNMR before. You can choose between standard processing, which only requires a few mouse clicks, or custom processing. The palette offers rapid access to the most frequently used functions. Open the palette with the command Tools > Palette. The tooltip (yellow tip) that appears when you hover the mouse over an icon tells you which command it corresponds to. When this manual says to use a command, you are free to choose it from the palette or from a menu or to use the corresponding keyboard shortcut.

To Process a Generic ¹H Spectrum:

  1. Open the file containing the spectrum.
    On the Mac, you can alternatively drag the folder containing the spectrum onto the iNMR icon.
  2. Choose the command Process > FT now.
    This command applies the standard processing automatically. On the Mac it appears when you hold down the alt key. If you prefer custom processing, choose, instead, Process > Fourier Transform. It opens a dialog for setting zero-filling, weighting and other options.
  3. Adjust the amplification, if necessary.
    A double-click inside the plot area changes the amplification so that the tallest peak fits in the window. The plus and minus keys have an intuitive effect on amplification.
  4. Correct the Phase.
    iNMR has already applied a rough automatic correction. If this is not enough, either choose Process > Automatic Phase or correct the phase manually.
  5. Correct the Baseline.
    Choose Process > Baseline Correction and click OK or, to make things faster, click the corresponding icon (slope with a gear).
  6. Calibrate the Frequency axis.
    Right-click the reference peak, choose Reference Scale and enter the correct ppm value.
  7. Define the Integral Regions.
    • Automatically: choose View > Auto-Integrate.
    • With the Integrator tool: drag over each multiplet.
    • Without the tool: select each region with the mouse and press “i” on the keyboard.
  8. To normalize the numerical values:
    Pick the integrator tool; double-click an integral; enter the normalized value.
  9. Pick the Peaks.
    Select the peak-picker tool, click at the desired threshold level and drag over the regions of interest. The threshold should be above the noise and below the peaks you want to detect.
  10. Extract Chemical Shifts and Coupling Constants.
    Choose View > J couplings to open the module called J Manager; select a multiplet and press “e” on the keyboard. To generate a formatted list, click the icon report, in the J Manager.

This is only one possible workflow. Most commands offer alternative methods, shortcuts and advanced options.

Related Topics

About Processing

2-D Processing