Physicochemical and Antioxidant Properties of Humic Acids from Low-Sulfur Kazakhstan Shales.

Autor: Suimbayeva, S. M., Kairbekov, Zh. K., Maloletnev, A. S., Kishibayev, K. O., Dzheldybaeva, I. M.
Zdroj: Coke & Chemistry; Sep2022, Vol. 65 Issue 9, p386-391, 6p
Abstrakt: The structural, chemical, and physicochemical characteristics and antioxidant properties of humic acids isolated from shale in the Kenderlyk and Kiin fields are determined. Negative values of the acids' oxidation are found: –3.62 and –4.06 for Kenderlyk and Kiin shale, respectively. Thus, the shale-based humic acids are reducing agents. IR spectroscopic data show clear absorption bands of hydroxyl, functional, and carbonyl groups. ESR spectroscopy indicates a high content of paramagnetic centers in the humic acids: 9.3 × 1017 and 9.5 × 1017 spin/g for Kenderlyk and Kiin shale, respectively. The paramagnetic centers in the molecular structure of the humic acids indicate that they are promising as antioxidants. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index