Nonextractable residue formation of sulfonamide antimicrobials: new insights from soil incubation experiments.
Soil incubation experiments using (14)C-labelled sulfamethazine were carried out to assess the factors governing its nonextractable residue (NER) formation via nucleophilic addition reactions. Circumstantial evidence on possible mechanisms of NER formation was derived from a selective manipulation of soil samples. The amount of quinones in soil available for nucleophilic addition was a limiting factor as indicated by (i) an (initial) increase of NER formation by adding quinone precursors or enhancing their formation by manganese oxide addition and (ii) a decrease of NER formation by limiting the formation of quinones under anaerobic conditions. A slow NER formation with time under aerobic conditions is likely caused by covalent bonding as well, because no slow NER formation phase was observed under anaerobic conditions.
Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, 8600 Dübendorf, Switzerland; Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zürich, Universitätstrasse 16, 8092 Zürich, Switzerland.
Anna
A
Gulkowska
Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, 8600 Dübendorf, Switzerland.
Basilius
B
Thalmann
Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, 8600 Dübendorf, Switzerland; Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH Zürich, Universitätstrasse 16, 8092 Zürich, Switzerland.
Juliane
J
Hollender
Department Effect-Directed Analysis, UFZ - Helmholtz Centre for Environmental Research, Permoserstrasse 15, 04318 Leipzig, Germany. Electronic address: martin.krauss@ufz.de.
Martin
M
Krauss
D000332:Aerobiosis; D000693:Anaerobiosis; D000890:Anti-Infective Agents / Q000737:chemistry*; D006873:Hydroquinones / Q000737:chemistry; D017895:Manganese Compounds / Q000737:chemistry; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry; D009195:Peroxidase / Q000037:antagonists & inhibitors / Q000378:metabolism; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*; D013418:Sulfamethazine / Q000737:chemistry*
D000890:Anti-Infective Agents; D006873:Hydroquinones; D017895:Manganese Compounds; D010087:Oxides; D012987:Soil; D012989:Soil Pollutants; D013418:Sulfamethazine; C027424:manganese oxide; D009195:Peroxidase; C031927:hydroquinone
Nonextractable residues; Nucleophilic addition; Sequential extraction; Sulfonamide antimicrobials