Mercury‐modified Lignosulfonate‐stabilized Gold Nanoparticles as an Alternative Material for Anodic Stripping Voltammetry of Thallium

Abstract

Lignosulfonate‐stabilized gold nanoparticles (AuNPs‐LS) were synthesized and subsequently used as a complexing agent for mercury ions. The obtained AuNPs‐LS/Hg2+ complex was characterized by means of various physicochemical techniques such as UV‐vis spectroscopy, transmission electron microscopy and cyclic voltammetry. Furthermore, the resulting complex was evaluated as an electrode modifier for the development of amperometric sensors. Upon sufficient negative potential, the bound mercury ions are reduced to form an amalgam with AuNPs‐LS. Thus, the performance of glassy carbon electrode (GCE) modified by AuNPs‐LS/Hg film was investigated as an electrochemical sensor in the determination of Tl+ ions in a 0.05 M EDTA at pH 4.5. The presence of the mercury containing film improves the analyte accumulation due to its ability to form a fused amalgam with thallium. The presented data indicate that the GCE/AuNPs‐LS/Hg modified electrode shows better performance toward Tl+ determination in comparison to bare GCE. The stripping anodic peak current of thallium was linear over its concentration range from 1.7⋅10−7 to 5.0⋅10−6 M. The detection limit (3σ) was estimated to be 1.4⋅10−7 M. The proposed method was successfully applied for the determination of thallium ions in real samples of soil derived from the area of the copper smelter near Głogów (Poland).

Electrode Modified by Reduced Graphene Oxide for Monitoring of Total Thallium in Grain Products

“…The applied accumulation potential is sufficiently low to reduce thallium ions to the metallic form. [ 24 ]. Control measurements were performed together with each series of experiments.…”

Thallium in color tattoo inks: risk associated with tattooing

“…Lead and Tl exhibit similar electrochemical properties. As a result, the overlapping voltammetric signals from both metals are usually observed in systems containing no complexing electrolytes [13]. To avoid such a problem, EDTA can be added.…”

New Electrode Material GCE/AgNPs‐LS/Hg Based on Nanosilver Produced with the Use of Biopolymers

“…Another example that uses DPASV is the modification of the glassy carbon electrode with reduced graphene oxide (RGO). In this case, the linearity range was from 9.78 ⋅ 10 −9 to 97.8 ⋅ 10 −9 mol dm −3 and the LOD was 6.01 ⋅ 10 −9 mol dm −3 [10]. Using a bismuth film electrode (BiFE) and strip voltammetry (ASV), the linearity in the range from 2 ⋅ 10 −9 to 3 ⋅ 10 −8 mol dm −3 and the LOD of 6 ⋅ 10 −10 mol dm −3 were obtained [11].…”

“…In recent decades, many solid electrodes have been used to determine trace metals (also thallium).The most representative examples are electrodes made of precious metals such as silver and gold, transition metals (the so‐called bismuth foils, antimony‐based electrodes) and various carbon electrodes with ex situ electrolytically deposited layers of mercury (film mercury electrodes) [5–9].…”

“…For example, the GCE/AuNPs‐LS/Hg electrode, that is used in Differential Pulse Anodic Stripping Voltammetry (DPASV). This technique resulted to a linearity ranging from 1.7 ⋅ 10 −7 to 5 ⋅ 10 −7 mol dm −3 , with a limit of detection (LOD) of 1.4 ⋅ 10 −7 mol dm −3 [8]. Another example that uses DPASV is the modification of the glassy carbon electrode with reduced graphene oxide (RGO).…”