Chemically modified carbon paste electrode for the detection of lead, cadmium and zinc ions

Abstract

Purpose This paper aims to develop an inexpensive, portable, sensitive and environmentally friendly electrochemical sensor to quantify trace metals. Design/methodology/approach A sensor was constructed by modifying carbon paste electrode for the determination of lead, cadmium and zinc ions using square wave anodic stripping voltammetry (SWASV). The modified electrode was prepared by inserting homogeneous mixture of 2-hydroxy-acetophenonethiosemicarbazone, graphite powder and mineral oil. Various important parameters controlling the performance of the sensor were investigated and optimized. Electrochemical behavior of modified electrode was characterized by cyclic voltammetry. Findings Modified carbon pastes electrodes showed three distinct peaks at −0.50, −0.76 and −1.02 V vs silver/silver chloride corresponding to the oxidation of lead, cadmium and zinc ions at the electrode surface, respectively. The highest peak currents for all the metal ions under study were observed in the phosphate buffer solution at pH 1 with a deposition time of 70 s. The sensor exhibited linear behavior in the range of 0.25-12.5 μg mL-1 for lead and cadmium and 0.25-10.0 μg mL−1 for zinc. The limit of detection was calculated as 78.81, 96.17 and 91.88 ng mL−1 for Pb2+, Cd2+and Zn2+, respectively. The modified electrode exhibited good stability and repeatability. Originality/value A chemically modified electrode with Schiff base was applied to determine the content of cadmium, lead and zinc ions in aqueous solutions using SWASV.

Electrochemical determination of traces lead ions using a new nanocomposite of polypyrrole/carbon nanofibers

“…However, the use of these electrodes as sensors requires an improvement of their properties. Chemically modified carbon paste electrodes (CMCPEs) have been introduced as a suitable approach to improve their analytical performances mainly including the sensitivity, selectivity, stability, and detection limit [18][19][20][21].…”

Renesansa elektroda s ugljikovom pastom; njihove modifikacije i primjene u potenciometrijskim određivanjima farmaceutika

“…surfactant modified zeolite carbon paste electrode). 7,81,82 Od teških metala, uz pomoć CPE primjenjujući elektroanalitičke tehnike, osim žive 21,83 i bakra, [84][85][86] različiti autori su opisali primjenu CPE za određivanje olova, [86][87][88][89] kadmija, 86,88,90,91 cinka, 86,88 talija, [92][93][94] kositra, 91 bizmuta, 95,96 antimona 97 i dr. Potenciometrijom se uz CPE mogu odrediti maseni udjeli aluminija niži i od 10 −9 . 98 Sve gore navedene elektrode od ugljikove paste pokazale su se kao dovoljno osjetljive, selektivne i pouzdane u određivanju niskih koncentracija ispitivanih analita.…”

Proposing a Selective Electrochemical Sensor for Pb2+ Prepared from Fish‐Waste‐Derived Hydroxyapatite/Gelatin nanocomposite

“…[9][10][11] Graphite-modified electrodes have been extensively developed due to their low cost, high selectivity, sensitivity, specific surface area, electrical conductivity, mechanical flexibility and extreme resistance to oxidation. [12] Furthermore, these properties can be improved by adding modifiers in their composition. [13] Hydroxyapatite, HA (Ca 10 (PO 4 ) 6 (OH) 2 ), is thermodynamically the most stable calcium phosphate under physiological conditions in human body and has a very similar composition to bone mineral.…”

“…Moreover, modified electrodes offer the researcher the advantage of using a wide range of electrode materials, depending on their specificities and availabilities [9–11] . Graphite‐modified electrodes have been extensively developed due to their low cost, high selectivity, sensitivity, specific surface area, electrical conductivity, mechanical flexibility and extreme resistance to oxidation [12] . Furthermore, these properties can be improved by adding modifiers in their composition [13] …”