Effect of gamma irradiation on properties of soil humic acids.

摘要

The aim of this work was to identify if humic acids are relatively resistant not only to chemical and microbiological factors but to gamma irradiation too. HAs samples were extracted from soil samples (LAS - from O-horizon of Albic Aresonol under pine forest; PUL - from Ap horizon of Haplic Luvisol used for agriculture; TOR - from 0-30 layer of Eutri-Fibric Histosol) and purified by the standard Schnitzer's methods. Samples of HAs were divided into those that have been exposed to gamma radiation and those that have not been exposed to radiation. In the experiment "cobalt bomb" was used with 60Co as the source of gamma rays. Time of irradiation of samples was 1.5 months; the radiation dose was 160 kGy. Irradiated and not irradiated HAs samples were analyzed for: elemental composition, infrared, 13C-NMR CP/MAS solid state and UV-VIS spectra. Obtained results showed that humic acids are resistant to gamma irradiation at the dose of 160 kGy. Elemental composition, UV-VIS, IR and NMR analysis of irradiated HA samples did not differ from comparable HA samples not irradiated. Studies have shown clearly the differrentiation in structure and properties of HAs depending on their source of origin (type of soil).