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International Conference on

Recent Trends in Environmental Sustainability

ESCON22/NMsB/36
Electrochemical determination of some environmentally important anions using
modified and unmodified multiwalled carbon nanotubes paste electrodes

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Abdul Niaz , Sania Bibi , Muhammad Iqbal Zaman
1 Department of chemistry, University of Science & Technology, Bannu, Khyberpukhtunkhwa
Correspondence: niazchemist2k6@yahoo.com

Abstract

The determination of anions such as sulphide and nitrite are essential for environmental
significance. For this purpose, a sensitive and simple cyclic voltammetric (CV) assay using
multiwalled carbon nanotubes paste electrode (MWCNTPE) has been proposed for the direct
detection of sulphide. Sulphide exhibited a distinct oxidation peak at about 0.56V in NaCl as a
suitable supporting electrolyte. The oxidation peak current values were found to increase in a
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linear way as the concentration of sulphide increased in the range from 1×10 to 3×10 M (R
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= 0.9985). The detection limit was 4×10 M. The proposed method exhibited high selectivity
towards the oxidation of sulphide than other competing anions. A CV method has also been
developed for the determination of nitrite by using a MWCNTPE modified with chitosan-
functionalized silver nanoparticles. By combining the advantages of chitosan, AgNPs and
MWCNT, the assay exhibited a remarkable improvement in the cyclic voltammetric response
towards the oxidation of nitrite. The oxidation peak current increased linearly in the range
from100 nM to 50 μM for nitrite concentration and the detection limit was found to be 30 nM.

Keywords: multiwalled carbon nanotubes, sulphide, cyclic voltammetric

Department of Environmental Sciences, COMSATS University Islamabad, Vehari Campus

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