Poly(catechol) Film Modified Glassy Carbon Electrode for Ultratrace Determination of Cerium(III) by Differential Pulse Anodic Stripping Voltammetry

Abstract

Oxidative electropolymerization of resorcinol, catechol and pyrogallol at the glassy carbon electrode in different media such as 0.10 M NaOH, 0.10 M phosphate buffer (pH 7.00) or 0.10 M NaClO 4 all gave water-insoluble ®lms, adherent on the electrode surface. Amongst them electropolymerization of catechol at the GC electrode in 0.10 M NaOH provided a highly sensitive and selective ®lm for Ce(III) and therefore, this poly(catechol) ®lm modi®ed glassy carbon electrode was exploited for the selective preconcentration of Ce(III) at open circuit, followed by its determination by differential pulse anodic stripping voltammetry both in batch and¯ow systems. Factors affecting the accumulation, stripping and removal steps were investigated and an optimized procedure was then developed. Under optimized conditions, for batch determination, the calibration plot was linear in the concentration ranges 2X00 Â 10 À9 M 1X00 Â 10 À8 M and 2X00 Â 10 À8 M 1X00 Â 10 À7 M Ce(III). A detection limit of 2X0 Â 10 À10 M (0.027 ppb) (SN 3) was found for a 10 min accumulation. For six successive determinations of Ce(III) at concentrations of 2X00 Â 10 À7 , 2X00 Â 10 À8 and 2X00 Â 10 À9 M, relative standard deviations were 3.36 %, 1.76 % and 4.08 %, respectively. Similar results were obtained for continuous¯ow analysis. Interference from selected foreign ions and substances were examined. The developed method was applied to Ce(III) determination in human urine, both in batch and continuous¯ow systems.

Voltammetric and Spectroscopic Determination of Rare Earth Elements in Fresh and Surface Water Samples

“…The stripping peaks and detection limits for Ce(III) were very good, when compared with other voltammetric methods in existence. The detection limits compared well with studies obtained elsewhere [32,36,37]. Most researchers have found it difficult to produce discrete La(III) and Pr(III) analysis by voltammetric methods [38,39].…”

Preparation and General Properties of Chemically Modified Electrodes Based on Electrosynthesized Thin Polymeric Films Derived from Eugenol

“…0.9 V while a few times smaller cathodic one may be observed at ca. 0.4 V. Very similar voltammetric behavior was observed for Ce 3 incorporated into electropolymerized catechol [34]. It is also obvious when one compares the peak magnitudes for incorporated Cu 2 and Ce 3 that the former gives signi®cantly larger redox signals.…”

Modified carbon-containing electrodes in stripping voltammetry of metals

“…Organic substances (OS) [107][108][109][110][111][112][113][114][115][116][117][118][119][120][121], macrocyclic compounds [122][123][124][125][126], polymers [127-131, 157-159, 165-166, 169-175], bioactive compounds [186], and nanotubes [187][188][189][190] can also serve as GCE modifiers. Different combinations of the modifiers-a metal and OS [70-80, 97-105, 106], a polymer and a metal [86, 132-147, 160- [107][108][109][110][111][112][113][114][115][116][117][118][119][120][121][122][123][124][125][126] or the first modifying layer of mer...…”