Non - aqueous capillary electrophoresis separation of fullerenes and C 60 fullerene derivatives . 6 7 8

1 2 As the interest in the use of fullerene compounds in biomedical and cosmetic applications 3 increases, so too does the need to develop methods for their determination and quantitation in such 4 complex matrices. In this work we studied the behavior of C60 and C70 fullerenes in non-aqueous 5 capillary electrophoresis, as well as two C60 fullerene derivatives not previously reported by any 6 electrophoretic method, N-methyl-fulleropyrrolidine (C60 pyrr) and (1,2-methanofullerene C60)7 61-carboxylic acid (C60-COOH). . The separation was performed using fused-silica capillaries with 8 an I.D. of 50 μm and tetraalkylammonium salts, namely tetra-n-decylammonium bromide (TDAB, 9 200 mM) and tetraethylammonium bromide (TEAB, 40 mM), in a solvent mixture containing 6% 10 methanol and 10% acetic acid in acetonitrile:chlorobenzene (1:1 v/v) as the background electrolyte 11 (BGE). Detection limits, based on a signal-to-noise ratio of 3:1, were calculated and values between 12 1 and 3.7 mg/L were obtained. Good run-to-run and day-to-day precisions on concentration were 13 achieved with RDSs lower than 15%. For the first time, an electrophoretic technique (NACE) has 14 been applied for the analysis of C60 fullerene in a commercial cosmetic cream. A standard addition 15 method was used for quantitation and the result was compared with that obtained by analyzing the 16 same cream by LC-MS. 17