Palygorskite modified with N-doped carbon for sensitive determination of lead(II) by differential pulse anodic stripping
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ORIGINAL PAPER
Palygorskite modified with N-doped carbon for sensitive determination of lead(II) by differential pulse anodic stripping voltammetry Peng Yan 1 & Shilin Zhang 1 & Cunzhong Zhang 1 & Zishuo Liu 1 & Aidong Tang 1 Received: 13 August 2019 / Accepted: 17 September 2019 # Springer-Verlag GmbH Austria, part of Springer Nature 2019
Abstract A glassy carbon electrode (GCE) was coated with N-doped carbon-modified palygorskite and used as an electrochemical sensor for determination of Pb(II) by differential pulse anodic stripping voltammetry. To obtain high reproducibility and sensitivity, optimum experimental conditions for lead deposition are studied. Voltammetric responses of the modified GCE prepared with different ratios of carbon and palygorskite are examined under same conditions. Compared with a bare GCE, a N-doped carbon modified/GCE and a bismuth-modified GCE, N-doped carbon-modified palygorskite greatly improves the performance of GCE. Response is the best and the interfacial impedance is minimized if the fraction of carbon coating is 31%. This indicates that its performance is due to the synergies between palygorskite and N-doped carbon. Figures of merit for the modified GCE include (a) a preconcentration time of 180 s, (b) a detection limit of 0.42 μg·L−1 (2σ criterion), and (c) a linear response in the 4.0 μg·L−1 to 10.0 mg·L−1 Pb(II) concentration range. The method is successfully applied to the determination of Pb(II) in spiked tape water and gives recoveries between 97.1 and 104.3%. Keywords Clay-modified electrode . Nanocomposite . Modification of palygorskite . Conductivity . Electroanalysis . Alternating current impedance method . Detection of heavy metal ions . Measurement of lead
Introduction Differential pulse anodic stripping voltammetry (DPASV) is a powerful tool for the determination of trace heavy metal ions via Peng Yan and Shilin Zhang contributed equally to this work. Highlights • A glassy carbon electrode is modified by N-doped carbon coated palygorskite. • The modified electrode presents high sensitivity and reproducibility for detection Pb(II) ion. • The synergy effect between palygorskite and N-doped carbon is confirmed. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00604-019-3843-5) contains supplementary material, which is available to authorized users. * Aidong Tang [email protected]; [email protected] 1
College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, People’s Republic of China
the combination of a credible preconcentration step with accurate electrochemical measurement of the accumulated analytes [1–3]. Much attention is paid to the development of nonmercury electrode materials [4–6], especially various carbon paste electrodes. The advantages of carbon-containing composites are not only the enhancement of the conductivity but also their strong affinity with metal ions [7, 8]. Therefore, the improvement of the detecting performance can be achieved by the introduction of various
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