Determination of heavy metal poisoning antidote 2,3-dimercapto-1-propanesulfonic acid using silver solid amalgam electrode

• Published in: Electrochimica acta Vol. 354; p. 136623
• Main Authors: Hrdlička, Vojtěch, Choińska, Marta, Ruiz Redondo, Beatriz, Barek, Jiří, Navrátil, Tomáš
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 10.09.2020; Elsevier BV
• Subjects: 2,3-Dimercapto-1-propanesulfonic acid (DMPS); Anodic stripping; Antidotes; Cathodic stripping voltammetry; Complex formation; Electrodes; Electron transfer; Elimination voltammetry with linear scan; Heavy metals; Poisoning; Silver; Silver solid amalgam electrode; Sulfonic acid; Unithiol; Voltammetry; Elimination voltammetry with linear scan; Unithiol; 2,3-Dimercapto-1-propanesulfonic acid (DMPS); Silver solid amalgam electrode; Cathodic stripping voltammetry
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2020.136623

Voltammetric behavior of heavy metal poisoning antidote 2,3-dimercapto-1-propane-sulfonic acid (DMPS) was investigated using linear scan voltammetry (LSV), differential pulse cathodic stripping voltammetry (DPCSV), differential pulse anodic stripping voltammetry (DPASV), and elimination voltammetry with linear scan (EVLS) at a polished (p-AgSAE) and at a meniscus modified (m-AgSAE) silver solid amalgam electrode. It was confirmed that the mechanism of the electrode process involves two consecutive reductive desorptions with coupled proton/electron transfer preceded by a kinetic process prominent at higher scan rates as revealed by EVLS. Voltammetric and complexation behavior of DMPS in the presence of Pb2+ was further investigated by DPASV and DPCSV titrations confirming reductive desorption, complex formation, and transmetalation. Optimum conditions for DPCSV were as follows: Britton-Robinson buffer (BRB) of pH 10, Eacc = −200 mV and tacc = 30 s for p-AgSAE and BRB of pH 5, Eacc = 0 mV and tacc = 15 s for m-AgSAE. Limits of quantification (LOQs) and detection (LODs) were 0.3 and 0.1 μmol L−1 at m-AgSAE and 0.8 and 0.3 μmol L−1 at p-AgSAE, respectively. The practical applicability of the newly developed method was verified by determination of DMPS in commercial drug Dimaval and in human urine samples. [Display omitted] •New voltammetric method for determination of heavy metal poisoning antidote DMPS.•Submicromolar limits of detection at silver solid amalgam electrodes.•Applicability of the developed method verified using real urine sample analysis.•Complexing behavior of DMPS and Pb2+ examined by voltammetric titrations.•Study of reaction mechanisms using elimination voltammetry with linear scan.