INSTRUMENTAL NEUTRON-ACTIVATION ANALYSIS OF TRACE-ELEMENT IMPURITIES IN GRAPHITE SOOT, GOLD GRADE C-60 AND C-70 AND IN SUPER GOLD GRADE C-60

Actually the purity of fullerenes is in general characterized as the p ercentage of the main component (e.g. C-60) versus the higher fulleren es (e.g. C-70, etc.) and/or in a few cases of some other polycyclic or ganic components. We are reporting here for the first time detailed da ta on trace element impurities in fullerene precursors and in the main fullerenes. For studying the element impurities instrumental neutron activation analysis (INAA) was used. Our measurements have shown that all these materials contain trace elements at ppb (ng/g) and ppm(mu g/ g) levels. From the results it comes out that in the future investigat ions of the elemental purity of the C-60 and C-70, and even of the hig her fullerenes would have to be also considered when their electrical, magnetic, etc. properties are studied.