Measurement of Copper Complexing Ability of Humic Acids by Using Diethylaminoethyl Sephadex A-25 Column

Abstract

A method for the measurement of copper complexing ability of humic acids by using diethylaminoethyl Sephadex A-25 is reported. Since the A-25 resin can adsorb copper-humic acid complexes, but not free copper ions, the free copper ions were fractionated and then determined by graphite-furnace atomic absorption spectrometry. Conditional stability constants and complexing capacities of the humic acids were estimated by Scatchard plot adapting to two-site model. The method could be applied to the humic acids from peat soil, and the copper complexing ability of the humic acids could be estimated sensitively and simply.