title: Molecular structure of fulvic acids by electrospray with quadrupole time-of-flight mass spectrometry.
abstract: Characterisation of the molecular structure of aquatic fulvic acids (FA) has been performed using a quadrupole time-of-flight (Q-TOF) mass spectrometer equipped with an electrospray ionisation interface. Molecular masses centred around 450 Da and sinusoidal spectral distributions have been obtained for all fulvic acids. Tandem mass spectrometry (MS/MS) experiments showed losses of 18 Da (H(2)O) and 44 Da (CO(2)), and possible molecular structures were determined for the first time to our knowledge. A methodology is reported for evaluating the average elemental composition of FA from high-resolution mass spectra by processing post-acquisition data calculations using molecular size distributions and atomic compositions of ions. The results are found to be consistent with elemental analysis data.
authors.affiliation: CEA Saclay, Bât. 391, DEN/DPC/SCPA/Laboratoire d'Analyse, de Synthèse et de Spéciation Organométallique, 91191 Gif-sur-Yvette, France. plancque@carnac.cea.fr
authors.forename: G
authors.initials: G
authors.lastname: Plancque
authors.forename: B
authors.initials: B
authors.lastname: Amekraz
authors.forename: V
authors.initials: V
authors.lastname: Moulin
authors.forename: P
authors.initials: P
authors.lastname: Toulhoat
authors.forename: C
authors.initials: C
authors.lastname: Moulin
mesh_terms: D001578:Benzopyrans / Q000032:analysis*; D019015:Geologic Sediments; D015394:Molecular Structure; D008970:Molecular Weight; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation / Q000379:methods*
chemical_list: D001578:Benzopyrans; C005023:fulvic acid