H. Rausch et al., Determination of sulfur as an impurity in commercial C-60, fullerene soot and sublimed C-60 polycrystals by INAA, ANALYST, 124(3), 1999, pp. 417-419
By using instrumental neutron activation analysis (INAA) it has been shown
that commercial C-60 products contain considerable amounts of sulfur impuri
ty. This element could be found in all C-60 samples of three main producers
which, in fact, necessitated to study the capabilities of the INAA sulfur
determination in more detail. Although only one sample did contain a surpri
singly high sulfur amount of about 8%, even the sublimed C-60 sample showed
a sulfur content of about 0.02%.