Details zur Publikation

Referenztyp Zeitschriften
DOI / URL Link
Titel (primär) Covalent binding of sulfamethazine to natural and synthetic humic acids: assessing laccase catalysis and covalent bond stability
Autor Gulkowska, A.; Sander, M.; Hollender, J.; Krauss, M.;
Journal / Serie Environmental Science & Technology
Erscheinungsjahr 2013
Department WANA;
Band/Volume 47
Heft 13
Sprache englisch;
POF III (gesamt) T32;
UFZ Querschnittsthemen RU2;
Abstract Sulfonamide antibiotics form stable covalent bonds with quinone moieties in organic matter via nucleophilic addition reactions. In this work, we combined analytical electrochemistry with trace analytics to assess the catalytic role of the oxidoreductase laccase in the binding of sulfamethazine (SMZ) to Leonardite humic acid (LHA) and to four synthetic humic acids (SHAs) polymerized from low molecular weight precursors and to determine the stability of the formed bonds. In the absence of laccase, a significant portion of the added SMZ formed covalent bonds with LHA, but only a very small fraction (<0.4%) of the total quinone moieties in LHA reacted. Increasing absolute, but decreasing relative concentrations of SMZ–LHA covalent bonds with increasing initial SMZ concentration suggested that the quinone moieties in LHA covered a wide distribution in reactivity for the nucleophilic addition of SMZ. Laccase catalyzed the formation of covalent bonds by oxidizing unreactive hydroquinone moieties in LHA to reactive, electrophilic quinone moieties, of which a large fraction (5%) reacted with SMZ. Compared to LHA, the SHA showed enhanced covalent bond formation in the absence of laccase, suggesting a higher reactivity of their quinone moieties toward nucleophilic addition. This work supports that binding to soil organic matter (SOM) is an important process governing the fate, bioactivity, and extractability of sulfonamides in soils.
ID 13892
dauerhafte UFZ-Verlinkung https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=13892
Gulkowska, A., Sander, M., Hollender, J., Krauss, M. (2013):
Covalent binding of sulfamethazine to natural and synthetic humic acids: assessing laccase catalysis and covalent bond stability
Environ. Sci. Technol. 47 (13), 6916 - 6924