The analytical procedure consisted of a closed-circuit accumulation
of eugenol onto the modified carbon paste electrode surface. The
preconcentration/voltammetric determination was used in all differential
pulse adsorptive anodic stripping voltammetric experiments. In the
first step the MCPE was immersed in 10 mL of phosphate buffer which
worked as an electrolyte containing a known amount of eugenol. The
deposition potential of +0.1 V was applied for 100 s while the solution
was stirring. The stirring was then stopped for a period of 10 s and the
potential was scanned in differential pulse mode (with 15 mV s−1
scan rate, 100 mV pulse amplitude and 40 ms pulse period) from 150
to 500 mV. The resulted oxidation peak registered at about +285 mV
and its currents were used as a measure of eugenol concentration.
Each scan was repeated three times with a new surface of electrode
for each analyzed solution and the mean of these voltammograms
was obtained. All experiments were carried out at room temperature