Composition and properties of an age sequence of charcoals and associated humic acids

Abstract

This paper reports results of infrared spectroscopy, differential thermal analysis, molecular weight fractionation, spark source mass spectroscopy, colour indexes, and carbon, nitrogen and ash analyses on carbon-dated humic acids extracted from charcoals in an age sequence. There does not appear to be any relationship between the properties obtained and the radiocarbon age of the humic acids or their parent charcoals. None of the methods used demonstrate any age-affecting contaminants. There is a significant correlation between copper and humic acid content of charcoals. This could be useful in determining humic acid content of small charcoal samples where extraction is not feasible.