In AMS measurements on small (m "d 400 µg) carbon samples, an m-dependence has been noted for the 14C/12C and 13C/12C ratios that is due to the combined effect of contamination and fractionation. A simple formalism is presented to describe the phenomena and to correct measurements on unknowns for their effect.
[Radiocarbon Volume 40, Numbers 1-2, 1998]