Fulvic acids: structure and metal binding. I. A random molecular model

Abstract

We have investigated a model of fulvic acid based on randomized positioning of functional groups and aromatic rings which can be used to deduce the types of metal chelating sites and provide statistical estimates of their concentrations. A FORTRAN program ‘RANDOM’ has been written which generates random molecules of fulvic acid. For each molecule generated the program also searches for and counts 14 types of binding site and calculates average concentrations over one thousand such molecules. A formula relating percentage aromatic carbon to the molar hydrogen/carbon ratio is also derived. The results show that the predominant bidentate sites are likely to be phthalate‐ and salicylate‐type sites with a significant proportion of aromatic carboxyl and phenolic hydroxyl not participating in chelating sites. Copyright © 1983, Wiley Blackwell. All rights reserved