With voltammetric techniques, soluble
reversible redox couples may pose interference
problems. The equilibrium concentrations
of such couples at the working electrode
are determined by the controlled
electrode potential according to the Nernst
equation. When the electrode potential exceeds
the characteristic potential of the
couple, a rapid, transport-controlled redox
conversion takes place and a Faradaic signal
is obtained as a result. Reversible couples
may often exist as intermediate products
when natural samples containing traces of
organic matter are subjected to voltammetric
analysis. With pulse voltammetric techniques,
where rapid potential steps are employed,
the effect is more pronounced than
with slow potential sweeps