This study was conducted to investigate radiochemiluminescence (RCL) spectra (340–650 nm), kinetics and absorption spectra
of humic acids (HA) after their exposure of γ-radiation (absorbed doses of 1–10 kGy, 60Co) in model systems. The kinetics and spectral distribution of RCL were measured using the single photon counting method
(SPC) and cut-off filters. Absorption spectra (range 240–800 nm) of irradiated solutions indicated that post-radiative degradation/polymerization
processes take place in the HA changing their macromolecule or properties. The intensity of the delayed RCL was nonlinearly
and suggested that complex radical formation mechanisms were still involved in the post-radiative reactions.