Transformation of 2,4,6-trimethylphenol and furfuryl alcohol, photosensitised by Aldrich humic acids subject to different filtration procedures

► Assessment of the photochemical activity of particles in Aldrich humic acids. ► Low to negligible probe transformation photosensitised by particles. ► 10% particle contribution to mass, organic carbon and radiation absorption. ► Negligible fluorescence of Aldrich humic acid particles. ► Hydrophobic particle core 1O2 activity is likely enhanced by absence of water.