There are no fullerenes in the K-T boundary layer

Careful re-examination of the Cretacous-Tertiary boundary layer material that was reported earlier to contain C-60, confirms that there is a peak in the HPLC of the extract having a retention time similar to that of C-60 (the basis of the earlier claim). However, mass spectrometric analysis shows this to be merely a mixture of hydrocarbons. No traces of either C-60 or C-70 are present under conditions capable of detecting as little as 50 pg (0.001 part per billion in the original material), this sensitivity being four times greater than that given in the earlier report. These findings are entirely consistent with the known high oxidative instability of fullerenes.