Determination of mercury(II) using a modified electrode with zeolite

Chemically modified carbon paste electrodes are prepared by incorporating appropriate quantities of a zeolite directly into the paste mixture. Trace levels of mercury(II) can be preconcentrated on these electrodes. Cyclic voltammetry is used to quantify the accumulated ions. The response is characterized with respect to preconcentration, pH, and other variables. The procedure exhibits good linearity for 0.11 μg/ml–2.2 μg/ml mercury(II) ions and the peak current varies linearly with preconcentration time between 1 and 6 min for the conditions used.