Carbon determination in human teeth by activation with He-3 ions.

A nuclear analytical method, involving activation with 3He ions, was developed to determine carbon content in human teeth with well-documented histories. The tooth samples were irradiated with 2.7-MeV3He particles at 50 nA intensity, and the activity of 14O induced through the reaction 12C(3He, n)14O, determined by counting the 2.31-MeV gammas. Different dental hard tissues were studied separately. A solid piece of silver steel, the carbon content of which was accurately determined by chemical means, was used as the standard. The carbon content in different teeth varied from 4-7%. The overall experimental accuracy was better than 4.5%.