A COMPARATIVE STUDY OF BUCKMINSTERFULLERENE AND HIGHER FULLERENE SEPARATIONS BY HPLC

摘要

Several HPLC columns that have been recommended for the separation of fullerenes were compared. Each column (i.e., stationary phase) had a different optimum mobile phase. In general, mobile phases consisted of binary mixtures of a ''good'' fullerene solvent and a ''poorer'' fullerene solvent. Reversed phase stationary phases with alkyl (aliphatic) substituents produced superior analytical separations for all fullerenes. However, stationary phases with aromatic substituents were better for preparative separations. Increasing the proportion of the ''poor'' fullerene solvent in the mobile phase generally increased resolution and retention but decreased the mass load. Injecting too high a concentration of fullerenes in any column caused peak splitting to occur. The fullerene retention order was the same on al columns and with all mobile phases. The fullerene separation ability of all columns tended to deteriorate with time. Overloading the column or doing preparative separations greatly accelerated the deterioration process. It is believed that irreversible adsorption of fullerenes or fullerene by-products is responsible for the degradation of column performance.