Cyclodextrins Based Enantioselective, Potentiometric Membrane Electrodes (EPME) and their Applications for Enantioanalysis of L-Cysteine in Urine

Four enantioselective, potentiometric membrane electrodes based on carbon paste impregnated with α-, β-, 2- hydroxyl-3-trimethylammoniopropyl -β- (as chloride salt) and γ-cyclodextrins are proposed for the enantioanalysis of Lcysteine. The proposed electrodes exhibited near-Nernstian slopes in a wide linear concentration range: 10-10 - 10-3 mol/L, with very low detection limits, near 10-11 mol/L. The surfaces of the electrodes are easily renewable by simply polishing on an alumina paper.