An electrochemical adaptation of Ellman's test.

The electrochemically initiated reaction of thiols with N,N-diethyl-p-phenylenediamine has been coupled with an existing colorimetric sensing reaction developed by Ellman as a means of providing an electrochemical adaptation of the latter whereby the total thiol species present in a sample can be determined. The detection methodology has been proven to be robust with a linear range for cysteine from 2-120 microM, a limit of detection of 1.17 microM and has shown selectivity against a wide range of potential interferences.

Sono-electroanalysis of copper: enhanced detection and determination in the presence of surfactants.

Surfactant adsorption has been shown to have a passivating effect on the electrode surface during anodic stripping voltammetric measurements. In the present work the feasibility of sono-anodic stripping analysis for the determination of copper in aqueous media contaminated with surfactant has been studied at an unmodified bare glassy carbon electrode. We illustrate the deleterious effect of three common surfactants, sodium dodecyl sulfate (SDS), dodecyl pyridinium chloride (DPC) and Triton-X 100 (TX-100) on conventional electroanalysis.