Cathodic stripping voltammetry of trace Mn(II) at carbon film electrodes

A sensitive voltammetric method is presented for the determination of tract levels of Mn (II) using carbon film electrodes fabricated from carbon resistors of 2 Omega. Determination of manganese was made by square wave cathodic stripping voltammetry (CSV), with deposition of manganese as manganese dioxide. Chronoamperometric experiments were made to study MnO2 nucleation and growth. As a result, it was found to be necessary to perform electrode conditioning at a more positive potential to initiate MnO2 nucleation. Under optimised conditions the detection limit obtained was 4 nM and the relative standard deviation for eight measurements of 0.22 nM was 5.3%. Interferences from various metal ions on the response CSV of Mn(II) were investigated, namely Cd(II), Ni(II), Cu(II), Cr(VI), Pb(II), Zn(II) and Fe(II). Application to environmental samples was demonstrated. (C) 2003 Elsevier B.V. All rights reserved.