Firstly, you don't call them peaks, and dont look at the peaks,

One tries to analyse the IR absorption bands, or dip.

Absorption bands less than 500 cm-1 would correspond to possible inorganic bonds between the elements in your material.

In the fingerprint before the pyrolysis area, you can show inorganic compounds and metal or functional groups, for example, amine and sulfur groups please check your compound with