Stripping-voltammetric determination of some amino acids on a carbon-paste electrode modified by crown ethers

Abstract

A method for detecting sulfur-containing amino acids on a carbon-paste electrode modified by dibenzo-18-crown-6 or dibromodibenzo-18-crown-6 ethers is developed. The selectivity of the method is accounted for by a specific interaction between crown ethers (modifying agents) and protonated amino groups of organic molecules of the analyte adsorbed by the surface of the modified electrode as a host-guest complex. The determination limits (clim) of cysteine, homocysteine, and glutathione are equal to (2-5) x 10-8 M. © 1997 MAEe Cyrillic signK Hayκa/Interperiodica Publishing