Chemical state assignment for tin is difficult due to overlapping Sn 3d5/2 values for SnO and SnO2 (see Table 1.). The Auger parameter and Auger spectral shapes may be helpful here (click for post).

Table 1. Sn 3d5/2 binding energy values.

Values from standards taken in this laboratory (MCB, unpublished results):
Sn(0)  - 484.90 eV, 0.59 eV FWHM at 10 eV pass energy, slightly asymmetric peak-shape defined  by LA(1.2,1.5,5).
Air formed oxide on polished Sn metal - 486.77 eV, 1.61 eV FWHM at 10 eV pass energy
ITO (Indium tin oxide) - 486.8 eV