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Differential pulse voltammetric determination of lead(II) with benzoin oxime‐modified carbon paste electrodes
Author(s) -
Tuzhi Peng,
Zhe Tang,
Guoshun Wang,
Baoen Shen
Publication year - 1994
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.1140060712
Subject(s) - anodic stripping voltammetry , detection limit , electrode , chemistry , benzoin , analytical chemistry (journal) , stripping (fiber) , oxime , carbon paste electrode , inorganic chemistry , cyclic voltammetry , materials science , chromatography , electrochemistry , organic chemistry , composite material
A new chemically modified electrode (CME) for determining lead(II) with high sensitivity and selectivity is reported. The electrode is constructed by adding benzoin oxime into a carbon paste mixture. The lead(II) is accumulated on the electrode surface by the formation of the complex in an open circuit, and then the resulting surface is characterized by medium exchange, potential reduction, and differential pulse anodic stripping voltammetry. In 10 deposition/measurement/regeneration cycles with a single surface, the response could be reproduced with 5.7% relative standard deviation. Quantitation of lead(II) from the peak current of the anodic wave for a 10 minute deposition time gives a detection limit of 8 × 10 −9 M (1.6 ppb). Linear calibration plots are obtained for lead(II) concentrations ranging from 10 −7 to 10 −8 M. The modified electrode preferentially accumulates lead from the solution, while most of the metal ions do not interfere with the determination. The mechanism of the accumulation of lead on the benzoin oxime‐modified electrode has been explored. Application to the determination of lead in wastewater is illustrated.