ACCEPTED MANUSCRIPT
The square wave voltammetry (SWV) is a very sensitive voltammetric technique
because of signal sampling that ensures low background noise. In addition, the fast
potential scanning achieved in SWV may provide a high analytical frequency [16]. On
the other hand, amperometric measurements made at fixed potentials simplify the
analytical procedure when compared to voltammetric approaches, especially when
batch-injection analysis (BIA) is performed. BIA only requires an electronic
micropipette, for fast and high-precise sample delivery, and a simple cell. It is a simpler
alternative to flow-injection analysis (FIA) as it not requires the use of system s with
pumps and valves [17]. In this approach, a microvolume of sample is delivered close to
the surface of the electrode where the analyte is readily reduced or oxidized generating a
transient signal that fades away as the convective transport dilutes the analyte in the
bulk of the solution in the electrochemical cell. This approach improves the analytical
frequency in amperometric analysis of simple matrices such as water [18] and
pharmaceutical samples [19].
In this work, two electroanalytical applications using the BDD electrode are
proposed for the determination of picoxystrobin in natural waters. The two approaches
were developed and compared, one based on SWV and other based on the amperometric
detection using the BIA system. A critical comparison was made in terms of detection
performance, interferences and analytical frequency and cost.