scholarly journals Anodic Stripping Voltammetry with the Hanging Mercury Drop Electrode for Trace Metal Detection in Soil Samples

Chemosensors ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 107
Author(s):  
Kequan Xu ◽  
Clara Pérez-Ràfols ◽  
Amine Marchoud ◽  
María Cuartero ◽  
Gastón A. Crespo

The widely spread use of the hanging mercury drop electrode (HMDE) for multi-ion analysis is primarily ascribed to the following reasons: (i) excellent reproducibility owing to the easy renewal of the electrode surface avoiding any hysteresis effect (i.e., a new identical drop is generated for each measurement to be accomplished); (ii) a wide cathodic potential window originating from the passive hydrogen evolution and solvent electrolysis; (iii) the ability to form amalgams with many redox-active metal ions; and (iv) the achievement of (sub)nanomolar limits of detection. On the other hand, the main controversy of the HMDE usage is the high toxicity level of mercury, which has motivated the scientific community to question whether the HMDE deserves to continue being used despite its unique capability for multi-metal detection. In this work, the simultaneous determination of Zn2+, Cd2+, Pb2+, and Cu2+ using the HMDE is investigated as a model system to evaluate the main features of the technique. The analytical benefits of the HMDE in terms of linear range of response, reproducibility, limit of detection, proximity to ideal redox behavior of metal ions and analysis time are herein demonstrated and compared to other electrodes proposed in the literature as less-toxic alternatives to the HMDE. The results have revealed that the HMDE is largely superior to other reported methods in several aspects and, moreover, it displays excellent accuracy when simultaneously analyzing Zn2+, Cd2+, Pb2+, and Cu2+ in such a complex matrix as digested soils. Yet, more efforts are required towards the definitive replacement of the HMDE in the electroanalysis field, despite the elegant approaches already reported in the literature.

1993 ◽  
Vol 58 (2) ◽  
pp. 291-294 ◽  
Author(s):  
M. Krystyna Pawlak

The effect of electroreduction of Zn(II), Cd(II), Pb(II) and Cu(II) ions on the stability of a film of the surfactant Triton X-100 on the surface of hanging mercury drop electrode was investigated. A procedure is suggested to disturb the film in order to facilitate the determination of the above metal ions by anodic stripping voltammetry with accumulation.


2016 ◽  
Vol 855 ◽  
pp. 3-8 ◽  
Author(s):  
Charuwan Khamkaew ◽  
Sontaya Manaboot

A simple, rapid, selective and sensitivity approach for the determination of Pb(II) in G. fisheri seaweed is described. The method is based on differential pulse anodic stripping voltammetry (DPASV) at hanging mercury drop electrode (HMDE) vs. Ag/AgCl in 0.2 M ammonium acetate (NH4OAc) pH 7.5. The operating analytical conditions; deposition potential (Edep) of -0.4 V, peak potential of -0.78 V, and mercury dropped size of 3 were performed. To see the sensitivity of Pb(II) measurement, the influences of deposition time and stirring speed were investigated. From the findings, the optimal parameters; deposition time of 90 s, and stirring speed of 2000 rpm were obtained. In these conditions, the limit of detection (3σ) of 0.60 µgL-1 and the linear range extended to 12.50 µgL-1 (r2=0.9999) were obtained. The relative standard deviation (RSD) of triplicate measurements using 1.8 µgL-1 of Pb(II) was 1.22%. The method was then applied to measure Pb(II) in real samples. In this study, the desorption efficiency of edible eluents by batch method was determined. The method is based on Pb(II) desorption using different types of edible eluents; acetic acid (HOAc), citric acid (CTA), sodium chloride (NaCl), sodium bicarbonate (NaHCO3), ethylenediaminetetraacetic acid (EDTA), and chitosan (CTS). Batch desorption of Pb(II) from seaweed soaked in individual eluent was performed by shaking at 100 rpm for 2 h at ambient temperature. Results show that the most effective eluent in desorbing the contaminated Pb(II) from G. fisheri with up to 82% of desorption efficiency for bound Pb(II) was EDTA solution.


2011 ◽  
Vol 701 (2) ◽  
pp. 152-156 ◽  
Author(s):  
José A. Rodrigues ◽  
Carlos M. Rodrigues ◽  
Paulo J. Almeida ◽  
Inês M. Valente ◽  
Luís M. Gonçalves ◽  
...  

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