Modification of chemical and conformational properties of natural organic matter by click chemistry as revealed by ESI-Orbitrap mass spectrometry

摘要: A click reaction is reported here for the first time as a useful technique to control conformational stability of natural organic matter (NOM) suprastructures. Click conjugates were successfully formed between previously butynylated NOM hydrophobic fraction and hydrophilic polyethylene glycol (PEG)-amino chain. The products shown by size exclusion chromatography (HPSEC) hyphenated with Orbitrap mass spectrometry (MS) in electrospray ionization (ESI) (+), while precursors visible ESI (-). Despite their increase molecular weight, HPSEC elution occurred after that precursors, thus showing departure from supramolecular association. This indicates click-conjugated molecules varied cationic character lost capacity accommodate original most abundant product had C16H30O5N4 formula, conjugate butanoic acid, other short-chained (C4-C8) linear unsaturated hydroxylated carboxylic acids. Tandem MS revealed formation triazole rings clicked two fragmentations at ester C-N alkyl-aryl bonds. behavior modified chemistry confirms hydrophobicity ionic charge humic play pivotal role stabilizing intermolecular forces NOM. Moreover, versatility may become decorate variety substrates, order alter chemical properties diversify its applications environment.