TITLE:
Determination of Lead in Water by Linear Sweep Anodic Stripping Voltammetry (LSASV) at Unmodified Carbon Paste Electrode: Optimization of Operating Parameters
AUTHORS:
Ndoye Mouhamed, Kane Cheikhou, Gadji Elhadji Momar Rokhy, Diédhiou Moussa Bagha, Mar-Diop Codou Guèye, Theo Tzedakis
KEYWORDS:
Carbon Paste Electrode, Lead, Linear Sweep Anodic Stripping Voltammetry, Water
JOURNAL NAME:
American Journal of Analytical Chemistry,
Vol.9 No.3,
March
16,
2018
ABSTRACT: This study presents the elaboration of a simple
and cheap electrode made by carbon paste introduced into a cavity of electrode
body, and used for the lead traces determination
in tap water. A potentiostatic pre-electrolysis at constant voltage enables the
reduction of the lead (Pb2+) and the accumulation of the metallic lead
at and into the carbon paste; the reoxidation of the Pb (Linear sweep voltammetry)
leads to the anodic striping peak. The effect of the main operating parameters on
the shape of the peak and the magnitude of the current was examined and their optimal values were
determined. Then calibration
was achieved and the method was successfully applied (using all the optimized parameters)
to the determination of lead in water, with a detection limit of 0.138 μg·L-1.
Compared to other methods (ICP-AES for
example), the
proposed method offers a satisfactory detection limit of the Pb2+ (0.138 μg·L-1) because of the important
specific area of the carbon paste electrode, for a significantly lower cost. Besides,
there is no observed loss in the electrode answer in terms of peak current, which
means that there is no any irreversible steps nor deactivation of the electrode,
even after ten successive measurements; only reduction of the lead followed by the
deposit oxidation was observed at the electrode.