Search results for "Differential pulse voltammetry"
showing 8 items of 18 documents
Platinum and rhodium associated with the leaves of Nerium oleander L.; analytical method using voltammetry; assessment of air quality in the Palermo …
2009
Abstract A rapid accumulation of the catalytic active noble metals in the environmental and biological matrices was observed and concern arose about potential environmental and health risks. The development of reliable analytic methods to measure very low Pt and Rh concentrations is required. The main purpose of this work was to develop a reliable method for the determination of Pt and Rh in environmental matrices because of inherent difficulties in using conventional techniques used, in particular, the ICP-OES technique. A direct determination of Pt using ICP-MS, for instance, is problematic, due to interfering signals. In this work, differential pulse voltammetry (DPV/a) and adsorptive st…
Electron transfer mechanism in Shewanella loihica PV-4 biofilms formed at graphite electrode
2012
Abstract Electron transfer mechanisms in Shewanella loihica PV-4 viable biofilms formed at graphite electrodes were investigated in potentiostat-controlled electrochemical cells poised at oxidative potentials (0.2 V vs. Ag/AgCl). Chronoamperometry (CA) showed a repeatable biofilm growth of S. loihica PV-4 on graphite electrode. CA, cyclic voltammetry (CV) and its first derivative shows that both direct electron transfer (DET) mediated electron transfer (MET) mechanism contributes to the overall anodic (oxidation) current. The maximum anodic current density recorded on graphite was 90 μA cm − 2 . Fluorescence emission spectra shows increased concentration of quinone derivatives and riboflavi…
Voltammetric Investigation on Uranyl Sorption by Alginate Based Material. Influence of Hydrolysis and pH Dependence
2015
The removal of U(VI) as uranyl (UO22+) from aqueous solutions was investigated by sorption onto alginate based material. The hydrolysis of uranyl ion was always taken into account in the calculations of free (22UO) ion in aqueous solution, in the experimental pH range considered, as well as the acid-base properties of alginate polymer. The sorption process follows a pseudo-second order kinetic model and the sorption rate decreases when the pH value increases. In addition to the classical Langmuir and Freundlich models, the equilibrium data were fitted by using a modified multi-component equilibrium model, never tested before. Differential Pulse Voltammetry (DPV) and Inductively Coupled Plas…
Probing the Conformational States of a pH-Sensitive DNA Origami Zipper via Label-Free Electrochemical Methods
2021
Funding Information: Financial support from EPSRC DTP (grant EP/R513349/1), the Emil Aaltonen Foundation, the Sigrid Jusélius Foundation, the Jane and Aatos Erkko Foundation, and the Vilho, Yrjö and Kalle Väisälä Foundation of the Finnish Academy of Science and Letters is gratefully acknowledged. This work was carried out under the Academy of Finland Centers of Excellence Programme (2014–2019). We acknowledge the provision of facilities and technical support by Aalto University Bioeconomy Facilities and OtaNano—Nanomicroscopy Center (Aalto-NMC) and Micronova Nanofabrication Center. Publisher Copyright: © 2021 The Authors. Published by American Chemical Society DNA origami structures represe…
Voltammetric Identification of Lead(II) and (IV) in Mediaeval Glazes in Abrasion-Modified Carbon Paste and Polymer Film Electrodes. Application to th…
2000
Direct identification of lead(II) and (IV) in glazed ceramics by cyclic voltammetry and differential pulse voltammetry is described. Characteristic cathodic and anodic profiles are obtained for microsample coatings in Paraloid B72-film electrodes immersed in NaCl and HAc/NaAc media. The electrochemical response of PbO, PbO2 and Pb3O4, and a series of test specimens of glaze is compared with that of microsamples extracted from the glaze of blue and white decorated ceramic produced in Manises (Spain) in the 15th century which have been buried in a damp place. Under abrasive conditions, striping peaks at –0.12 and –0.25 V (vs. SCE) appear for Pb(IV) centers and, at –0.55 and –0.75 V, for Pb(II…
Identification of Manganese(IV) Centers in Archaeological Glass Using Microsample Coatings Attached to PolymerFilm Electrodes
2001
Identification of MnO2 nodulae in archaeological glass by linear scan and differential pulse voltammetry using abrasive-conditioned microsamples attached to polymer film (Elvacite 2044) electrodes is described. Voltammetric responses for manganese-containing samples parallels to those obtained for β- and γ-MnO2 upon immersion of modified electrodes into NaCl, KCl and acetic/acetate aqueous media. The observed electrochemical response provides information on the open microporous structure of the MnO2 forms and the conditions of their formation during the weathering process of buried glass.
Synthesis, characterization and crystal structure of 2-dicyanomethylene-1,3-bis(ferrocenylmethyl)-1,3-diazolidine
1993
By reaction of N,N′-ethylenebis(ferrocenylmethylamine)1 with tetracyanoethylene in dichloromethane the yellow compound 2-dicyanomethylene-1,3-bis(ferrocenylmethyl)-1,3-diazolidine 2 can be isolated. The single-crystal structure of 2 has been determined. It crystallizes in the non-centrosymmetric trigonal space group P3221, a= 12.255(2), c= 13.831(7)A, Z= 3. Refinement of the atomic parameters by least-squares techniques gave a final R factor of 0.038 (R′= 0.034) for 1782 observed reflections having I > 2.5δ(I). Anomalous values of the bond distances and the vinyl carbon chemical shift in the 13C NMR spectrum of 2 are explained on the basis of a polarization due to a combination of the elect…
Evaluation of Flavonoid Derivative and Doxorubicin Effects in Lung Cancer Cells (A549) Using Differential Pulse Voltammetry Method.
2018
Purpose: Electrochemical measurements have prompted the progress as a consequence of their affectability, cost-affectivity and comparatively short examination time. The aim of this study was the fast evaluation of the effect of chemotherapy compounds on the viability of lung cancer cells (A549) via electrochemical methods. Methods: Cyclic voltammetry (CV) was used as a primary method to distinguish between electrochemical behavior of normal and lung cancer cells. Differential pulse voltammetry (DPV) was employed as a complementary analyses method for the impact of doxorubicin (DOX) and Flavonoid modified drug (FMD) (US patent Application number: 62548886) on Lung cancer cells. Results: Only…