Microwave-assisted extraction of C60 and C70 from fullerene soot

Microwave-assisted extraction (MAE) was examined as an alternative to the traditional Soxhlet method of extracting C(60) and C(70) from fullerene soot. MAE of 0.20 g of fullerene soot with 95:5 toluene-acetonitrile yielded greater than 7.8 mg of C(60) and greater than 0.54 mg of C(70) in 4 min with no further increase in yield after 30 min of irradiation. By comparison, exhaustive Soxhlet extraction of the same size sample with the same solvent yielded 7.1 mg of C(60) and 0.58 mg of C(70) in 340 min. Re-extraction by MAE of soot initially extracted by Soxhlet increased the yield of Soxhlet alone. Although MAE was limited to less than 0.5-g sample per extraction vessel, multiple samples were extracted with minimal increased extraction time and no reduction in the amount of material recovered.