J. Debroux G. Aiken G. Amy P. Westerhoff 1999 <p><span>Hydrophobic organic acids (combined humic and fulvic acids), obtained from an Antarctic Lake with predominantly microbially derived organic carbon sources and two US river systems with terrestrial organic carbon sources, were ozonated. Several analyses, including&nbsp;</span>¹³<span>C‐NMR, UV absorbance, fluorescence, hydrophobic/transphilic classification, and potentiometric titrations, were performed before and after ozonation. Ozonation reduced aromatic carbon content, selectively reducing phenolic carbon content. Ozonation of the samples resulted in increased aliphatic, carboxyl, plus acetal and ketal anomeric carbon content and shifted towards less hydrophobic compounds.</span></p> application/pdf 10.1080/01919512.1999.10382893 en Taylor & Francis Ozone-induced changes in natural organic matter (NOM) structure article