Chemical oxygen demand sensor employing a thin layer electrochemical cell

A chemical oxygen demand sensor employing a thin layer electrochemical cell was constructed using a sandwich-type thin layer working electrode. The el ectrode was constructed by attaching face to face glass and copper plates s eparated by PTFE spacers to create an extremely shallow cell. After filling the cell by capillary action, it was possible to measure reproducibly the coulometric charge required for exhaustive electrolysis, with a single meas urement taking 3-10 min according to the kind or the concentration of the s ample. The results obtained are compared with those obtained in our former work using the same standards and real samples from lakes. A new artificial water sample was found to behave similarly to real samples. (C) 1999 Elsev ier Science B.V. All rights reserved.