Electrochemical detection of trichloroethylene with an electrodeposited Pb-modified electrode

The amperometric sensing of trichloroethylene (TCE) in the organic phase by using modified Pb electrode was described. The influence of pretreatment, electrodeposition current density, electrodeposition time, and electrodeposition temperature for preparation of the working electrode were discussed. The optimal conditions for preparation of modified Pb electrode were obtained as 0.1 M HNO3 pretreatment, 20 mA/cm(2) electrodeposition current density, and 30degreesC electrodeposition temperature. Additionally, the optimal sensing conditions such as -2.10 V sensing potential [vs. Ag/Ag+ with 0.1 M tetrabutylammonium perchlorate in acetonitrile (AN) solution], 155 rpm agitation rate, and at room temperature with 0.01 M tetrabutylammonium tetrafluoroborate electrolyte concentration in AN solution were obtained in this system. Under the optimal sensing conditions, the results indicated that the response time was 20 s (90% response time) and the correlation of sensing response current, i(d), and TCE concentration, C-L, is i(d)=1.060 C-L in the range from 100 to 700 ppm. Furthermore, the rate constant of TCE mass transfer, k, was also obtained to be 7.217x10(-4)/cm s. (C) 2003 The Electrochemical Society.