title: Fractionation of fulvic acids: characteristics and complexation with copper.
abstract: Two fulvic acid samples isolated from Suwannee river (International Humic Substance Society) and Feeitsuey reservoir were subjected to gel filtration chromatography (GFC) for molecular size fractionation. The GFC-eluted samples were separated into three groups corresponding to the molecular weight ranges: < 220, 220-1000, and 1000-4000. Fluorescence quenching techniques were employed for determining the conditional stability coefficient and kinetic parameters of copper complexation with the three fractions of fulvic acids. Experimental conditions were pH 6, 5 x 10(-5)m total copper and 5 mg C litre(-1) of fulvic acids. The conditional stability coefficients of the fulvic acid fractions were in the order of 0.9-3.3 x 10(5)m(-1), and the forward and reverse rate constants were in the order of 6.9-12.4 x 10(3)m(-1) s(-1) and 3.5-8.0 x 10(-2) s(-1). Information could be useful in modelling copper transport in the hydrosphere.
authors.affiliation: Graduate Institute of Environmental Engineering, National Taiwan University, Taipei, Taiwan, Republic of China.
authors.forename: C F
authors.initials: CF
authors.lastname: Lin
authors.forename: D Y
authors.initials: DY
authors.lastname: Lee
authors.forename: W T
authors.initials: WT
authors.lastname: Chen
authors.forename: K S
authors.initials: KS
authors.lastname: Lo