Artículos de revistas
The complexation of marine and terrestrial organic materials with copper (II) ions as determined by fluorescence quenching
Registro en:
Chemical Speciation And Bioavailability. Science & Technology Letters, v. 9, n. 1, n. 27, n. 34, 1997.
0954-2299
WOS:A1997XM36600004
Autor
Lombardi, AT
Jardim, WF
Institución
Resumen
Copper complexation parameters, e.g., conditional stability constant (K') and ligand concentration (CL), were obtained for marine DOM and soil fulvic acid (SFA). Complexometric titrations using Cu(ll) as the titrant were monitored by fluorescence quenching and data treatment was performed using a two-binding site model. The marine DOM was isolated by partitioning onto tC18 Sep-Pak cartridges and followed by a reverse phase-high performance liquid chromatography fractionation. The SFA was investigated before and after receiving the same treatment as the marine sample. The results show that there is a loss of ligands with high affinity for copper as a result of the Sep-Pak treatment on the SFA. The Sep-Pak processed SFA ligands are associated with fluorophores with excitation wavelength at 350 nm. The more polar chromatographic fractions have higher values of CL/TOC, obeying a linear relation. A linear relation was also observed between total quenching (100-I-ML and normalised CL values (CL/TOC). 9 1 27 34