Analyses of relatively uncontaminated " (super 14) C-dead" samples of wood suggest that backgrounds of 0.11 or -0.04 p MC are obtainable for both the ABOX-SC and ABA-SC procedures.
Where wood is significantly contaminated the ABOX-SC technique provides significantly better decontamination than either the ABA-SC technique or cellulose extraction alone, although CE-SC can produce comparably low backgrounds to the ABOX-SC procedure.
These atoms rapidly decay into radiocarbon-dioxide and along with ordinary CO2 are absorbed by living plants.
As plants enter the human and animal food chains the C14 dioxide enters their living tissue.
Even then, there remains an inbuilt age effect, albeit somewhat reduced.
In the late 1950's, the issue of presample age was identified as a causal factor in the difficulties encountered in accurately cross-dating the Julian calendar with that of the Yucatan Maya of Lowland Mexico.
We compare radiocarbon accelerator mass spectrometry (AMS) ages of wood samples subjected to a conventional acid-base-acid pretreatment with stepped combustion (ABA-SC) with results from the same samples subjected to an acid-base-wet oxidation pretreatment with stepped combustion (ABOX-SC) and cellulose extraction with stepped combustion (CE-SC).
Nor can it tell if a much older spearhead was attached to a brand-new shaft.Radiocarbon or C14 dating employs complex systems of measuring the unstable isotopes in once living matter.There are three forms of carbon that naturally occur forming the building blocks of all plant and animal life.The stable C12 and C13, and the unstable or radioactive Carbon 14. Only one C14 atom exists for every one trillion C12 atoms.Nitrogen atoms in the upper atmosphere are struck by cosmic radiation and create C14 atoms.