Square wave voltammetric detection by direct electroreduction of paranitrophenol (PNP) using an organosmectite film-modified glassy carbon electrode

Guy B P Ngassa; Ignas K Tonlé; Emmanuel Ngameni

doi:10.1016/j.talanta.2015.10.030

Square wave voltammetric detection by direct electroreduction of paranitrophenol (PNP) using an organosmectite film-modified glassy carbon electrode

Talanta. 2016 Jan 15:147:547-55. doi: 10.1016/j.talanta.2015.10.030. Epub 2015 Oct 19.

Authors

Guy B P Ngassa¹, Ignas K Tonlé², Emmanuel Ngameni³

Affiliations

¹ Laboratory of Analytical Chemistry, Faculty of Science, The University of Yaounde 1, P.O. Box 812, Yaounde, Cameroon.
² Laboratory of Analytical Chemistry, Faculty of Science, The University of Yaounde 1, P.O. Box 812, Yaounde, Cameroon; Chemistry of Materials and Electrochemistry, Faculty of Science, University of Dschang, P.O. Box 67, Dschang, Cameroon. Electronic address: itonle@yahoo.com.
³ Laboratory of Analytical Chemistry, Faculty of Science, The University of Yaounde 1, P.O. Box 812, Yaounde, Cameroon. Electronic address: engameni@yahoo.fr.

PMID: 26592645
DOI: 10.1016/j.talanta.2015.10.030

Abstract

This work describes the development of a low-cost and reliable adsorptive stripping voltammetric method for the detection of PNP in water. Organoclays were prepared by intercalation in various loading amounts of cetyltrimethylammonium ions (CTA(+)) in the interlayer space of a smectite-type clay mineral. Their structural characterization was achieved using several techniques including X-ray diffraction (XRD), N2 adsorption-desorption (BET method) and Fourier Transform Infrared spectroscopy (FTIR) that confirmed the intercalation process and the presence of the surfactant ions within the clay mineral layers. Using [Fe(CN)6](3-) and [Ru(NH3)6](3+) as redox probes, the surface charge and the permeability of the starting clay mineral and its modified counterparts were assessed by multisweep cyclic voltammetry, when these materials were coated on the surface of a glassy carbon electrode (GCE). In comparison with the bare GCE, the organoclay modified electrodes exhibited more sensitive response towards the reduction of paranitrophenol (PNP). Under optimized conditions, a calibration curve was obtained in the concentration range from 0.2 to 5.2µmolL(-1); leading to a detection limit of 3.75×10(-8)molL(-1) (S/N=3). After the study of some interfering species on the electrochemical response of PNP, the developed sensor was successfully applied to the electroanalytical quantification of the same pollutant in spring water.

Keywords: Electroreduction; Film modified electrode; Organosmectite; Paranitrophenol; Voltammetric detection.