Can you please specify what you mean by quantization/quantification? These are different things, but it's unclear in both cases what you actually want.

Of course, the XPS gives me data on the amount of oxygen species I have with respect to the different binding energies they have, so I would like to know if I can distribute them on a plane of oxidized graphene

What you can do is provide percentages of the different carbon species, back in my PhD time this was the reference we built from:

Article Atomic Oxygen on Graphite: Chemical Characterization and The...

An absolute stoichiometry can in principle be calculated by using cross sections/sensitivity factors, but especially when you work with a topping layer this might get distorted results because of the different electron escape path lengths. [That doesn't exclude that a reviewer will demand it nonetheless.]