Optimizing Conditions for Ultrasound Extraction of Fullerenes from Coal Matrices.

Conditions for ultrasound toluene extraction of synthetic C60 added to powdered bituminous coal were tested. High-performance liquid chromatography (HPLC) was used to determine the fullerene content in the obtained extracts. The results indicated a possible negative effect of sample demineralization (HCl/HF) and N2 purging on the extraction yield of C60. On the contrary, a 30% yield increase was registered when the coal was pre-extracted with pentane or pentane/toluene. The best conditions for C60 recovery in the investigated mixtures are 30 min of sonication at 280-285 K. The effects of sample filtration, sequential extraction, ultrasound bath power and treatments of C60 solution alone are also discussed. [ABSTRACT FROM AUTHOR]