Analysis of minor constituents in fullerene soots by LC-MS using a heated pneumatic nebulizer interface with atmospheric pressure chemical ionization

• Published in: Canadian journal of chemistry 1992-10, Vol.70 (10), p.2558-2568
• Main Authors: Anacleto, J. F, Boyd, R. K, Pleasance, S, Quilliam, M. A, Howard, J. B, Lafleur, A. L, Makarovsky, Y
• Format: Article
• Language: English
• ISSN: 0008-4042; 1480-3291
• DOI: 10.1139/v92-325

The minor constituents of toluene extracts of three fullerene-rich materials have been characterized by on-line LC-MS techniques, incorporating both positive and negative ion mass spectra obtained by atmospheric pressure chemical ionization. Two of the materials were soots, produced by resistive heating of graphite in an inert atmosphere, from different commercial suppliers. The third material was obtained as a condensate from a controlled laminar flame, and was shown previously (Anacleto etal:, Rapid Commun. Mass Spectrom. 6 , 214 (1992)) to contain significant quantities of compounds that behaved under the present LC-MS conditions as isomers of the C 60 and C 70 fullerenes, and which reverted to the latter upon heating. This finding was confirmed here, and extended to the higher clusters C 76 , C 84 , C 90 , and C 94 . One of the graphite-derived soots contained monoxides of the carbon clusters as the principal minor components, while the other soot contained hydrogenated species including C 60 H 2 , C 60 H 4 , C 70 H 2 , and (C 60 *CH 4 ). The flame-generated material contained all of these minor constituents, together with complexes of C 60 with larger aliphatic molecules as well as large quantities of polycyclic aromatic hydrocarbons and related species. Photo-oxidation of a purified C 60 preparation, from the graphitic soot containing mostly monoxide impurities, was shown to lead to increased levels of the mono-, di-, and tri-oxides of C 60 .