Anodic stripping voltammetry (ASV) has been recognized as
a powerful technique for electrochemical measurements of trace
metal ions in various samples of environmental, clinical, and
industrial origin [1], in particular due to its capability of preconcentrating
analytes at/in the surface of the working electrode,
allowing quantificationofheavymetalionsdownto lowmicrogram
per liter or even nanogram per liter concentration levels [2]. Mercury
has been the electrode material of choice for many stripping
applications. Two basic electrode systems, the mercury film electrode
(MFE) and hanging mercury electrode (HMDE), have gained
wide acceptance in the development of ASV [3]. However, nowadays
mercury electrodes are considered undesirable due to the
toxicity of both metallic mercury and the mercury salts employed
for the preparation of MFEs. Therefore, alternative environmentally
friendly electrode materials are required.
The bismuth-film electrode (BiFE) was introduced around the
year 2000 as an alternative to mercury electrodes due to its
stripping behaviors similar to those of mercury electrodes and
the environmentally friendly nature of bismuth [4]. Its attractive
characteristics include performance comparable to the traditional
mercury electrodes, a wide potential window, partial insensitivity
to dissolved oxygen for the determination of metals at trace