Microwave-assisted extraction of C-60 and C-70 from fullerene soot

Microwave-assisted extraction (MAE) was examined as an alternative to the t raditional 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 seat er than 7.8 mg of C-60 and greater than 0.54 mg of C-70 in 4 min with no fu rther increase in yield after 30 min of irradiation. By comparison, exhaust ive Soxhlet extraction of the same size sample with the same solvent yielde d 7.1 mg of C-60 and 0.58 mg of C-70 in 340 min. Reextraction by MAE of soo t initially extracted by Soxhlet increased the yield of Soxhlet alone. Alth ough MAE was limited to less than 0.5-g sample per extraction vessel, multi ple samples were extracted with minimal increased extraction time and no re duction in the amount of material recovered. (C) 1999 Elsevier Science B.V. All rights reserved.