The chemical and sorptive characteristics of mineral coals extracted from a mine in Lebu (Biobío Region, Chile) and its derivatives were studied. These derivatives were obtained by applying a thermal treatment in an environment with N 2 and CO 2 at different experimental conditions, in order to increase their specific surface. In addition, coals were characterized by using proximal analysis, elementary analysis and petrographic analysis. In order to know their structure and surface, Boehm titration analysis, FTIR infrared spectroscopy, X-ray diffraction and scanning electron microscopy were performed. The surface of the selected carbons was modified by selectively oxidizing it with (NH 4 ) 2 S 4 O 8 and with H 2 O 2 e impregnating with an iron solution for the study with H 2 O 2 In the oxidation of H 2 O 2 , the work was carried out at different pH. The results show a moderate homogeneity between different types of seams studied, whereas when coals are treated with heat or strong oxidants, increases its surface and can be used with analytical applications (v.g. electroanalytical sensors).