Accelerator Mass Spectrometry
For measurement of carbon isotopes
The CAIS operates a 500 kV compact AMS unit for precise analyses
of carbon isotopes C-12, C-13, and C-14 at extremely low (parts
per quadrillion) concentration levels.
The National Electrostatics Corporation Model 1.5SDH-1 Pelletron
Accelerator Mass Spectrometer, installed in January 2001, provides
the means to directly count the number of C-14 atoms in a sample,
so that even extremely small (microgram size) samples can be
used for quantitative determinations of very low-level isotopic
Precision of C-14 measurements is better than 0.3%. The
sensitivity of the instrument is comparable to that of much larger
units, with theoretical detection limits as low as 4 attomoles
(4 x 10-18 moles) of C-14. Geological graphite 14C/12C ratios average 7.5 x 10-16.
The CAIS presently offers a sample preparation service, which
involves the conversion of carbonaceous materials to graphite
and submission for AMS analysis. Samples sent for AMS preparation
must contain at least 2 mg of carbon by weight.
For a less expensive analysis, samples may also be submitted
pre-prepared to CO2
or graphite form.
Images Publications Analytical
For further information contact Dr.
G.V. Ravi Prasad at (706) 542-5579