Roxarsone binding to soil-derived dissolved organic matter: Insights from multi-spectroscopic techniques

摘要: The fate and transport of roxarsone (ROX), a widely used organoarsenic feed additive, in soil is significantly influenced by the ubiquitous presence soil-derived dissolved organic matter (DOM). In this study, fluorescence quenching titration two-dimensional correlation spectroscopy (2D-COS) were employed to study ROX binding DOM. Binding mechanisms revealed lifetime measurement Fourier transform infrared (FTIR). Humic- protein-like fluorophores identified excitation-emission matrix synchronous spectra conditional stability constant (log KC) for DOM was found be 5.06, indicating that strongly bound order 2D-COS followed sequence fluorophore ≈ the longer wavelength excited humic-like (L-humic-like) fluorophore > the shorter (S-humic-like) fluorophore. resolved issues with peak overlapping allowed further exploration interaction between Results FTIR demonstrated interacted through hydroxyl, amide II, carboxyl, aliphatic CH, NO2 groups, yielding stable DOM-ROX complexes. strong implies plays an important role environmental soil.