The permeability characteristics and analytlcal applications of a thin-layer glassy carbon detector coated with cellulose acetate film are descrlbed. Access to the surface can be manipulated via a controlled base-hydrolysis of the fllm. As a result of excluding macromolecules from the surface, the stablilty and selectivity are greatly Improved. The range of applications can be extended vla a careful choice of the hydrolysis period. By adding a new dimension of selectivity based on molecular slre, hlgh spectficlty toward smaller analytes Is demonstrated In both flow Injection and ilquld chromatographic systems. Electrode polsonlng, due to protein adsorption or accumulation of reactlon products, Is mlnlmlred.Complex chromatograms can be greatly slmpllfled without lowering the operating potential. The coated electrode exhlblts extension of the linear range, In situations where a nonllnear response Is obtalned at the bare electrode. Varlous analytes and lnterferents, representing a wide range of molecular slres, are tested. Appllcablllty to urine samples Is demonstrated.

No abstract

No abstract

No abstract