Chromatogram & Peak calculations

Area

Chromatogram area is calculated only where peaks are located, in particular:

  • Detected peaks, that are within Integrable Range. These regions are highlighted green when you’re editing Integration Method. If such a peak touches non-integrable ranges, then it’s not considered.

  • Manually selected or modified peaks. Even if it’s inside the non-integrable range, the area of this peak gets included in the chromatogram area.

The actual integration of the area is done using Trapezoidal rule.

Peak Area%

Peak Area% = 100 * Peak Area / Chromatogram Area

Peak Retention Time

Retention Time (RT) is taken as the highest point of a peak.

However, Peaksel will never use the boundary point as RT, so if the highest point is at the peak boundary (happens in case of round peaks and shoulders), then the neighbor point is used.

Peak Base, BPM, λmax

If a detector captures spectra (Mass Spec, DAD/PDA), then for every peak we calculate its mean spectrum (available if you double-click on the peak label). The base is the highest point in the mean spectrum.

The Base of the peak corresponds to:

  • Base Peak Mass in case of Mass Spectrometry

  • λmax (the most absorbing wavelength) in case of DAD/PDA

Peak IsManual

If you modify the peak boundaries manually or move the peak or select a new peak with a mouse, it’s considered manually modified. In visualization tables such peaks have IsManual column filled with true.