title: Targeted borate complex formation as followed with electrospray ionization Fourier transform ion cyclotron mass spectrometry: monomolecular model system and polyborate formation.
abstract: Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) was applied to identify boric acid(B degrees)/borate(B-) complexes in a monomolecular model system, composed of aqueous caffeic acid and boric acid/borate solutions in various concentration ratios at pH 9.2. Using negative mode electrospray ionization as a 'soft' ionization technique, clusters of polyborate were detected beside the well-known BL degrees , BL- and BL2- complexes. An algorithm for the detection of boron complexes, based on their accurate mass and isotope patterns, is proposed which enabled the assignment of elemental compositions/structural formulae of boron/ligand complexes. We present experimental evidence of self-oligomerization of up to six borate units with caffeic acid, resulting in stable covalently bound polyborate-polyol complexes.
authors.affiliation: Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Institute of Ecological Chemistry, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany.
authors.forename: Andras
authors.initials: A
authors.lastname: Gaspar
authors.forename: Mourad
authors.initials: M
authors.lastname: Harir
authors.forename: Marianna
authors.initials: M
authors.lastname: Lucio
authors.forename: Norbert
authors.initials: N
authors.lastname: Hertkorn
authors.forename: Philippe
authors.initials: P
authors.lastname: Schmitt-Kopplin
mesh_terms: D001881:Borates / Q000737:chemistry*; D002109:Caffeic Acids / Q000032:analysis; D003373:Coumaric Acids / Q000032:analysis; D017357:Cyclotrons; D005583:Fourier Analysis; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D011108:Polymers / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D001881:Borates; D002109:Caffeic Acids; D003373:Coumaric Acids; D007202:Indicators and Reagents; D011108:Polymers; C004999:ferulic acid; C040048:caffeic acid