Formation of nonextractable residues of Sulfonamides with organic matter - Mechanisms and Detection by High Resolution Tandem Mass Spectrometry

When sulfonamides reach the soil, sorption to the solid phase is one main process influencing their translocation, biodegradation, and ecotoxicity. After a few weeks of sorption a major part of sulfonamides cannot be recovered from soil by conventional extraction methods. The added sulfonamides thus form “nonextractable residues” (NER). The mechanisms postulated for NER formation are either physical entrapment in organic matter or covalent bond formation. Current approaches to characterize NER of xenobiotics rely mostly on NMR spectroscopy utilizing isotope labeled compounds. Recent soft ionization mass spectrometric studies on organic matter isolates encouraged us to develop a method based on soft ionization high resolution mass spectrometry to study NER formation mechanisms. This method will be applied to identify the mechanisms of NER formation of selected sulfonamides with organic matter isolates.

Funding

Swiss National Science Foundation