Which isotope of carbon is used in radioactive carbon dating

20 Sep

A δ13C value, then, represents the per mille (part per thousand) deviation from the PDB standard.PDB refers to the Cretaceous belemnite formation at Peedee in South Carolina, USA.Please email the lab for the rates.*****In order to provide radiocarbon determinations that are both accurate and precise, it is necessary to correct for “isotopic fractionation” using the stable isotopes 13C and 12C.This correction factors out error introduced from metabolic and respiratory pathway differences between the modern reference standard material and the sample material. Two δ13C values are measured at Beta Analytic: – One is the value applicable to correct for total fractionation (natural, chemistry and AMS).Isotopic fractionation of stable carbon isotopes Carbon-13 (13C) and Carbon-12 (12C) involves alterations in the ratios of isotopic species as a function of their atomic mass as a result of natural biochemical processes.Variations as such are unrelated to time and natural radioactive decay.

The δ13C value for a sample can yield important information regarding the environment from which the sample comes or the mixtures of materials used to produce it because the isotope value of the sample reflects the isotopic composition of the immediate environment.

This value is representative of the sample itself and is reported. In comparison, reporting the “AMS δ13C” is misleading and open to misinterpretation.

Radiocarbon users should always be aware whether the δ13C they are using in their research is the IRMS δ13C or the AMS δ13C.

If it is the AMS δ13C, it cannot be used for dietary or metabolic pathway studies.

Reported δ13C values from Beta are always the values measured in the IRMS.