ULTRAHIGH RESOLUTION MASS SPECTROMETRY OF AQUATIC HUMIC SUBSTANCES:RECURRING MOLECULAR THEMES AND POLYMERIC CHARACTER

摘要

High-field Fourier Transform Ion Cyclotron Resonance Mass Spectrometry combined with Electrospray Ionization(ESI FT-ICR MS)is currently the only analytical technique capable of fully resolving individual molecules in complex humic mixtures.(Stenson et al.2002;Kujawinski et al.,2002)The ultra-high resolution mass spectra revealed multiple peaks at every nominal mass unit separated by as little as 0.0364 Dalton,as well as the presence of molecular families containing ions that differ from each other in degree of saturation,functional group substitution,and number of-CH_2-groups.(Stenson et al.2003)