Dating for the organic
Results suggest that collagen, free of humic acids, yields reliable results and is the only reliable organic fraction for dating fossil bone.
Humic acids that are not removed by standard pre-treatment are a prime suspect in the contamination of 'collagen' and can lead to dates that are too old as well as too young.
Unsatisfactory results with the carbon-14 dating of bone organic matter have caused bone radiocarbon dates to be considered unreliable.
Even the so-called collagen dates are commonly erroneous for samples more than a few thousand years old.
(author)International Atomic Energy Agency, Vienna (Austria); Joint Commission on Applied Radioactivity of the International Council of Scientific Unions, Paris (France); 744 p; Aug 1967; p.