Simultaneous determination of C-60 and C-70 fullerenes by a spectrophotometric method

In all fullerene-producing systems, reaction products were black soot extra cts reported to contain a 5-25% fullerene mixture. Toluene extraction of th e soot results in a solution of C-60, C-70, and higher fullerenes. Without separation, absolute determination of the contents is not possible, leaving the researcher to comment only on the C-60/C-70 ratio of the solution. Hig h-performance liquid chromatography, nuclear magnetic resonance, and scanni ng tunneling microscopy imaging techniques were reported in the literature for determining the C-60/C-70 ratio of the mixtures. These methods require tedious experiments and produce slightly differing results as well. In this communication, a new and relatively quick method is proposed for the simul taneous determination of the yields of C-60 and C-70 (not the ratio) in ful lerene-containing solutions by ultraviolet-visible spectrophotometric analy sis.