UNSUITABILITY OF C-12(60) AS A STANDARD OF ATOMIC-WEIGHT

A critical discussion is given of the suggestion by Dougherty et al. ( J. Am. Sec. Mass Spectrom. 1994, 5, 120) that the C-12(60) molecule re place the C-12 atom as the primary standard of atomic mass. Adoption o f the proposed standard would require that the unified atomic weight/m ass scale, finally achieved with much difficulty in 1960, be abandoned without demonstrable benefit. Furthermore, the proposed standard has a molecular mass that is inherently ambiguous at a level that makes it unacceptable for that purpose.