title: Characterization of humic substances using capillary electrophoresis with photodiode array and laser-induced fluorescence detection.
abstract: The effect of organic modifiers (organic solvents and urea) on the electrophoretic buffer was investigated in an attempt to enhance resolution in the finger-printing of two humic substances (HS): an aquatic fulvic acid (FA) and a soil humic acid (HA). Two detection modes, photodiode array and laser-induced fluorescence, were applied. The addition of organic solvents (acetonitrile, acetone, 2-propanol and tetrahydrofuran) in 10 mM Na2B4O7 (pH 9.0) resulted in a clear difference in electrophoretic behavior of the studied HS compared to the absence of organic solvents. There were also marked differences in the electrophoretic profiles using a 2-propanol-borate buffer with urea. The study of the interaction between metals and HS showed that there was a change in the migration pattern in the presence of A1(III), indicating the specific binding sites of aluminum.
authors.affiliation: Analysis and Methods Division, Environmental Technology Centre, Environment Canada, Ottawa.
authors.forename: M
authors.initials: M
authors.lastname: Nordén
authors.forename: E
authors.initials: E
authors.lastname: Dabek-Zlotorzynska
mesh_terms: D000433:1-Propanol / Q000737:chemistry; D000096:Acetone / Q000737:chemistry; D000097:Acetonitriles / Q000737:chemistry; D001578:Benzopyrans / Q000032:analysis*; D001881:Borates / Q000737:chemistry; D019075:Electrophoresis, Capillary; D005453:Fluorescence; D005663:Furans / Q000737:chemistry; D006812:Humic Substances / Q000032:analysis*; D007834:Lasers; D008670:Metals; D012997:Solvents / Q000737:chemistry; D014508:Urea / Q000737:chemistry
chemical_list: D000097:Acetonitriles; D001578:Benzopyrans; D001881:Borates; D005663:Furans; D006812:Humic Substances; D008670:Metals; D012997:Solvents; C018851:borax; D000096:Acetone; C018674:tetrahydrofuran; D014508:Urea; D000433:1-Propanol; C005023:fulvic acid; C032159:acetonitrile