Radiolabelling of humic material by enzymatically mediated incorporation of 14C-phenol

This paper discusses the production of 14C-labelled sodium humate by horseradish peroxidase mediated incorporation of 14C-phenol. The use of solubilised horseradish peroxidase and immobilised horseradish peroxidase during labelling is compared. 14C-polyphenol may be produced during the reaction but is reduced to 2% of the total radioactivity when the immobilised form of the enzyme is used in the reaction. The radiolabelled material is stable with respect to time and migration through sand. The mobility of the radiolabelled humic material through sand columns is investigated and is shown to be dependent on the production route. Radiolabelled humic prepared using the immobilised enzyme exhibits enhanced mobility through sand columns compared to radiolabelled humic prepared using either the soluble form of the enzyme or 14C-methylamine to radiolabel the humic.