ABSTRACT
Adsorptive stripping voltammetry (AdSV), developed in the late
1970s, is an analytical method. Many researchers have paid atten-
tion to this method, due to it can determine extensive objects. The
combination of an effective preconcentration step with advanced
electrochemical measurements of the accumulated analytes makes
AdSV the most sensitive electroanalytical technique [1, 2]. Its
remarkable sensitivity is attributed to the built-in preconcentration
step in which the target molecules are accumulated onto the work-
ing electrode. Proper choice of the working electrode is crucial for
the success of the adsorptive stripping operation. The ideal working
electrode should offer effective preconcentration, a favorable redox
reaction of the target molecules, a reproducible and renewable
surface, and a low background current over a wide potential
range. Mercury has been the electrode material of choice for many
AdSV applications. Two basic electrode systems, the mercury film
electrode (MFE) and the hanging mercury drop electrode (HMDE),
have gained wide acceptance in the development of AdSV [1-4].
While these small-volume mercury electrodes offer an attractive
stripping performance, new alternative electrode materials with
similar performance are urgently desired for addressing growing
concerns regarding the toxicity, handling, volatility, and disposal of
mercury. Future regulations and occupational health considerations
may severely limit (and even ban) the use of mercury as an electrode
material. Such concerns regarding the toxicity of mercury electrodes
are particularly important in view of the growing demands for
on-site environmental analysis and decentralized clinical material
testing. Different bare carbon, gold, silver, or iridium electrodes
have been used as possible alternatives to mercury [5, 6]. While
offering useful stripping signals for several materials, the overall
performance of these “nonmercury” electrodes has not approached
that of mercury ones due to a low cathodic potential limit, multiple
distorted (multiple/broad) peaks, large background contributions,
or poor precision and resolution. Hence, the development of reliable
nonmercury electrodes is considered a major challenge for AdSV in
the early stage of the 21st century.
