High-performance liquid chromatographic study of nickel complexation with humic and fulvic acids in an environmental water

Abstract

A high-performance liquid chromatographic method was developed to determine cation-exchange capacities and conditional association constants for metal interactions with humic and fulvic materials present in environmental waters. The method does not require prior extraction of the humic and/or fulvic compounds. A salt-gradient is used, which exploits the size-exclusion and adsorption properties of a coated porous silica stationary phase, in order to separate and permit the measurement of the free and complexed metal concentrations. The results are subjected to a weak and strong binding site interpretation.