DIRECT ELECTROCHEMICAL DETECTION OF C-60 IN SOLUTION BY STEADY-STATE VOLTAMMETRY AT MICROELECTRODES

The direct electrochemical detection of C-60 in solution was investiga ted by steady-state voltammetry at Pt microelectrodes. Highly reproduc ible voltammograms were obtained in 1,2-dichlorobenzene with 0.050 M t etra-n-butylammoniumhexafluorophosphate as supporting electrolyte, usi ng a freshly polished electrode surface. Linear correlation between th e limiting current of the first reduction step and the C-60 concentrat ion was excellent (r = 0.9999) for concentrations in the range of 1.0 x 10(-5) to 1.0 x 10(-3) M. The detection Limit of C-60 was 8.2 x 10(- 6) M (5.9 mg/L). At higher concentrations (up to 3.0 x 10(-2) M), the measured limiting currents were up to 6.6% below those expected by ext rapolation of the linear domain. The technique was applied to the dete rmination of the solubility of C-60 in toluene, dichloromethane, trich loromethane, tetrahydrofuran, and dimethylformamide, and for the estim ation of the total fullerene content of a commercial carbon soot, by t he standard addition method.