Enantioselective potentiometric membrane electrodes based on C(60) fullerene and its derivatives for the assay of l-Histidine.

Novel enantioselective, potentiometric membrane electrodes (EPMEs) based on carbon paste impregnated with C(60) fullerene (I), (1,2-methanofullerene C60)-61-carboxylic acid (II), diethyl(1,2-methanofullerene C60)-61-61-dicarboxylate (III) and tert-butyl(1,2-methanofullerene C60)-61-carboxylic acid (IV) are reported. Response characteristics showed that the proposed electrodes could be reliably used in the assay of l-Histidine (l-His), with the best enantioselectivity and time-stability exhibited by fullerene derivatives. The surfaces of the electrodes are stable and easily renewable by simply polishing on an alumina paper. All proposed electrodes proved to be successful for the determination of the enantiopurity of histidine as raw material and of its pharmaceutical formulation.