Spectrus: Understanding “Intensity” vs “Integral” values for NMR data in Spectrus

Description
In NMR, intensity and integral represent different numerical measures:

• Intensity is the height of a peak at a specific frequency point (amplitude of the signal).
• Integral is the area under the peak (or multiplet), proportional to the number of nuclei contributing to that signal.

Spectrus displays and uses both, and it is important to know when to rely on each.

Solution

1. Intensity (peak height):
   • Used mainly for:
     • Peak picking.
     • Comparing signal‑to‑noise.
   • Sensitive to:
     • Line broadening.
     • Resolution/processing parameters.
2. Integral (area):
   • Represents the relative number of nuclei contributing to a signal (e.g., relative number of protons).
   • Less sensitive to small shape changes than peak height, provided baseline and phasing are correct.
3. In Spectrus:
   • Ensure that spectra are properly phased and baseline‑corrected before relying on integrals.
   • Use Integral values when:
     • Determining proton counts in multiplets.
     • Comparing relative stoichiometry.
   • Use Intensity values when:
     • Evaluating S/N.
     • Identifying weak vs strong peaks.
4. For quantitative work:
   • Always base your evaluation on integrals, not intensities.
   • Verify integrals against known reference signals (e.g., solvent peak, standard).