Electrochemical Determination of Hg2+ on a Poly (Eriochrome Blue Black R) Modified Carbon Paste Electrode
Abdoulkadri Ayouba Mahamane *
Laboratoire Matériaux, Eaux, Environnement (LAMEE), Faculté des Sciences et Techniques, Université Abdou Moumouni, BP:10662, Niamey, Niger.
Abdoulaye Idrissa Kalidou
Laboratoire Matériaux, Eaux, Environnement (LAMEE), Faculté des Sciences et Techniques, Université Abdou Moumouni, BP:10662, Niamey, Niger.
Hassane Adamou
Laboratoire Matériaux, Eaux, Environnement (LAMEE), Faculté des Sciences et Techniques, Université Abdou Moumouni, BP:10662, Niamey, Niger.
Bachir Mijitaba Sahirou
Laboratoire Matériaux, Eaux, Environnement (LAMEE), Faculté des Sciences et Techniques, Université Abdou Moumouni, BP:10662, Niamey, Niger.
Alain Walcarius
Laboratoire de Chimie Physique et Microbiologie pour les Matériaux et l’Environnement, Université de Lorraine, 405 Rue de Vandoeuvre-54600 Villiers-lès-Nancy, Nancy, France.
Rabani Adamou
Laboratoire Matériaux, Eaux, Environnement (LAMEE), Faculté des Sciences et Techniques, Université Abdou Moumouni, BP:10662, Niamey, Niger.
*Author to whom correspondence should be addressed.
Abstract
In this work a new, simple, fast, and efficient electrochemical approach for the determination of inorganic mercury (Hg2+) using the differential pulse anodic stripping voltammetry (DPASV) technique was presented. This is achieved by modifying the surface of a carbon paste electrode by electropolymerization of Eriochrome blue black R. First, the behavior of Hg2+ on the modified electrode is studied by cyclic voltammetry and electrochemical impedance spectroscopy, to evaluate performance and understand the phenomena that take place on its surface. DPASV is then used to optimize the sensor in HClO4 medium. After optimization, a linear calibration graph was obtained in the concentration range of 1x10-9 to 9x10-9 mol.L-1 with correlation coefficient R2= 0.9975%, the limit of detection (LOD) and the limit of quantification (LOQ) obtained are respectively 3.23x10-10 mol.L-1 and 1.07x10-9 mol.L-1. The relative standard deviation (RSD) for 7 measurements is 3.07%, which proves that this sensor is reproducible. Finally, this method has been successfully applied in real samples of water and the results obtained are satisfactory because the recovery rates of Hg2+ vary from 99.2 to 100.1%.
Keywords: Carbon paste electrode, poly (eriochrome blue black R), inorganic mercury(II)`, differential pulse anodic stripping voltammetry