EasySpin forum

Double integration of experimental spectra for the purpose of spin quantitation should be used with great care. It is crucial that the calibration samples and the sample with the unknown concentration have the same spectra. This is because the double integral of a spectrum is not only proportional to the concentration, but also to the transition probabilities which vary with g values etc.

For proper quantitation, acquire your unknown sample and your calibration sample, simulate both of them, and compare the weights (Sys.weight) needed in the simulation to match the absolute intensities.