[artplumber]

Originally posted by greglepore
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Its widely reported that Landis's sample showed signs on spectrometry of exogenous t. That test itself is not foolproof, but it is considered to me more definative than the ratio itself.

The spectroscopy is a confirmatory test once the ratio is found to be abnormal, and looks specifically for the ratio of carbon isotopes to try to help determine if exogenous t was administered.