Hot-wire amperometric monitoring of flowing streams

This paper describes the design of a hot-wire electrochemical flow detector , and the advantages accrued from the effects of locally increased temperat ure, mainly thermally induced convection, upon the amperometric monitoring of flowing streams. A new hydrodynamic modulation voltammetric approach is presented, in which the solution flow rate remains constant while the tempe rature of the working electrode is modulated. Factors influencing the respo nse, including the flow rate, temperature pulse, or applied potential, have been investigated. The hot-wire operation results also in a significant en hancement of the flow injection amperometric response. The minimal flow rat e dependence observed with the heated electrode should benefit the on-line monitoring of streams with fluctuated natural convection, as well as variou s in-situ remote sensing applications. (C) 2000 Elsevier Science B.V. All r ights reserved.