PRECONCENTRATION OF COPPER TRACES ON C-60-C-70 FULLERENES BY FORMATION OF ION-PAIRS AND CHELATES

The adsorptive potential of C-60 and C-70 fullerenes for the preconcentration of copper traces was assessed for the first time in this work, The method used for this purpose involves the formation, adsorption on a fullerene minicolumn, and elution with 250 mu L of methyl isobutyl ketone of various ion pairs or chelates of copper. A sample loading time of 2 min provides an enrichment factor for copper between 40 and 185 relative to direct introduction of aqueous solutions into an atomic absorption spectrometer. The effect of concurrent cations was investigated in order to optimize the best chemical system (ion pairs or chelate) for the determination of copper. The systematic study carried out in this work allows us to conclude that the best selectivity and sensitivity are achieved with chelate formation and sorption on C-70 fullerene.