Study on the Interaction Between Chrysene with Humic Acids Using Fluorescence Spectroscopy

Abstract

The interaction between chrysene with humic acids (HA) was studied by the fluorescence spectroscopy. The results of fluorescence spectra revealed that chrysene could strongly quench the intrinsic fluorescence of HA through a static quenching procedure. The apparent binding constants K and number of binding sites n of chrysene with HA were 2.99 × 10⁵ and 1.0 which were obtained by the fluorescence quenching method. The thermodynamic parameters enthalpy change (ΔH), entropy change (ΔS) were negative, which indicated that the interaction of chrysene with HA was driven mainly by van der Waals forces and hydrogen bonds. The process of interaction was a spontaneous process in which Gibbs free energy change was negative. The results of three-dimensional fluorescence spectra showed that the chrysene entered into the hydrophobic cavities in some domain of HA.

Keywords:

• Chrysene
• fluorescence spectra
• humic acids (HA)
• interaction

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (41471399) and the National Natural Science Foundation for Young Scholars of China (No. 41401262, 41101474), Liaoning doctoral research foundation (201501076) and Scientific research project of Liaoning Provincial Education Department (L2016019).