Effect of humic acids on iron analyses in natural waters

Abstract

Florida river samples containing high and low concentrations of humic acids, naturally occurring chelators, were analyzed for iron content. The samples were subjected to automated microanalysis of soluble iron. Through statistical analyses of many replicate samples, it was possible to evaluate the error of analysis of low and high concentrations of iron in waters containing low and high concentrations of humic acid. Statistical evidence is presented to show that the presence of humic acid does not interfere in the precision of analysis of soluble iron and that changes in the iron content can be detected after storage for 2 months at -10°C.