Voltammetric Behavior of Lead(lI) at N-p-Chlorophenylcinhamohydroxamic Acid Modified Carbon Paste Electrode
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Date
1999-06
Authors
Hailu Tesfaye
Journal Title
Journal ISSN
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Publisher
Addis Ababa Universty
Abstract
A sensitive and selective method for the determination of lead(ll) with N-pchlorophenylcinnamohydroxamic
acid modified carbon paste electrode has been
developed. The iead(ll) is accumulated on the electrode surface by the formation of the
complex in an open-circuit/ and the resulting surface is characterized by medium
exchange, potential reduction, and differential pulse anodic stripping voltammetry. The
electrochemical response was evaluated with respect to carbon paste composition,pH
and concentration of accumulating and stripping solutions, preconcentration time,
lead(ll) concentration, and other variables. Two linear ranges were obtained in the
concentration ranges 1.00 x 10-6 - 2.40 x 10'5MPb(ll) with 2 min preconcentration time
and 2.00 x 10-8 - 1.00 x 10’6MPb(ll) with 6 min preconcentration time. The detection
limit was found to be 1.00 x 10 s M with 6 min preconcentration time. For six
preconcentration/medium exchange/voltammetric determination/renewal cycles, the
differential pulse voltammetric response was reproduced with 5.3% and 4.9% relative
standard deviations at 4.00 x 10*6Mand 8.00 x 104MPb(ll), respectively. Rapid and
convenient renewal allows the use of a single modified electrode surface in multiple
analytical determinations over several weeks. Many coexisting metal ions had little or
no effect on the determination of lead(ll). The developed method was applied to lead
determination in potable water
Description
Keywords
N-p-Chlorophenylcinhamohydroxamic Acid