Showing papers on "Polarography published in 1976"
TL;DR: In this article, a method based on differential pulse anodic stripping at an in situ mercury film coated rotatable glassy carbon electrode for the simultaneous determination of ultra-trace levels of Cd, Pb and Cu dissolved in sea water and inland waters and accumulated in marine organisms is presented.
Abstract: Toxic metals in sea and inland waters have become a significant research topic in the chemistry of the marine and inland aquatic environment. Advanced polarographic and voltammetric methods offer an expectional efficient and versatile approach to the determination, speciation and physicochemical characterization of those metals. These potentialities are reflected by a reliable method based on differential pulse anodic stripping at an in situ mercury film coated rotatable glassy carbon electrode for the simultaneous determination of ultra-trace levels of Cd, Pb and Cu dissolved in sea water and inland waters and accumulated in marine organisms. In speciation studies at trace levels differential pulse polarographic measurements revealed the influences of sea water components on the chelation of Cd with NTA and by the application of an advanced version of linear sweep anodic stripping voltammetry kind and stability of Pb-carbonato complexes existing in sea water could be elucidated.
144 citations
TL;DR: It was found that, as a consequence of adsorption of ds polynuclotides on the negatively charged electrode conformational changes similar to denaturation take place in a narrow potential region around -1.2 V (the region U).
142 citations
TL;DR: In this paper, the reduction potentials of a number of metal phthalocyanine complexes have been measured at a dropping mercury electrode in dimethylformamide, and the results of the investigation are discussed in the light of previous spectroscopic work with a view to correlating the electrode process with either ligand or metal reductions.
123 citations
118 citations
TL;DR: Anodic stripping voltammetry and differential pulse polarography are used to study complex formation between Cu(II), Pb(II, Zn(II) or Cd(II)) under concentration conditions which approximate those in natural waters as mentioned in this paper.
78 citations
71 citations
70 citations
TL;DR: In this paper, a single sweep voltammetry (measurement of the time integral of the reduction peak of adenine) and phase sensitive a.c. polarography (course of the capacitive current) at a hanging mercury drop electrode was performed at the charged mercury|solution interface.
46 citations
TL;DR: In this paper, the effect of various instrumental parameters is investigated and optimized conditions established in accordance with the theory of differential pulse anodic stripping voltammetry, and both a hanging mercury drop electrode and a rotating glassy carbon electrode mercury plated in situ were used.
43 citations
38 citations
TL;DR: In this article, the electrochemical behavior of DNA of various origin and of biosynthetic polynucleotides at a charged mercury/solution interface was studied in relation to their respective composition in bases.
TL;DR: Pulse polarization has been used widely for chemical analysis for both inorganic and organic compounds, and has an extensive literature as discussed by the authors, however, do polarography is not satisfactory at concentrations below about 10-5M, and resolution becomes very poor in the presence of a relatively large concentration of a more easily reduced depolarizer.
Abstract: Classical do polarography has been used widely for chemical analysis for both inorganic and organic compounds, and has an extensive literature (1). However, do polarography is not satisfactory at concentrations below about 10-5M, and resolution becomes very poor in the presence of a relatively large concentration of a more easily reduced depolarizer. For the purposes of improvement in sensitivity and resolution, a number of variations on do polarography have been developed (2). One of the best of these variations is pulse polarography. Pulse polarography was first developed by Barker (3) as the outgrowth of his work with square wave polarography. Several general articles on pulse polarography have been published (4-7). We present here the theory and applications of pulse polarography from an analytical point of view.
TL;DR: Theoretical approaches to explain the observed phenomena are discussed and it is concluded that apparently differing approaches that have appeared in the literature are in fact equivalent as discussed by the authors, and therefore strongly recommend that in systems in which adsorption is detected, polarography should not be used to determine stability constants.
TL;DR: In this article, the voltammetric behavior of cobalt and iron bis complexes with tridentate ligands, 2,6-bis (2-pyridyl)pyridine (TERPyridine), 4-phenyl pyridine and terosine (terosine), is described.
TL;DR: In this paper, the phase sensitive a.c. polarography of DNA extracted from the calf thymus has been studied in terms of the conditions of medium (ionic strength, pH) and of the molecular weight of DNA.
TL;DR: The electrochemical reduction of triphenyltin chloride at mercury electrodes in acetonitrile solution has been studied by cyclic voltammetry, polarography and controlled potential coulometry.
TL;DR: The use of a hanging mercury drop electrode with accumulation of elemental selenium followed by cathodic stripping gives detection limits in the range 0.1-1 p.p.b. as discussed by the authors.
TL;DR: In this article, a general equation for instant current in an electrode reaction coupled with a preceding first-order chemical reaction was derived with the condition (k 1 + k 2 )≫1, k 1 and k 2 being the rate constants of the chemical reaction.
TL;DR: In this paper, the half-wave potentials of permanganate, pertechnetate and perrhenate in organic solvents were obtained in terms of a.c.E.
TL;DR: In this paper, the electrochemical reduction of Mn 2 (CO) 10 at mercury electrodes has been studied in organic solvents by classical polarography, coulometry, chronopotentiometry and cyclic voltammetry.
TL;DR: In this paper, an elaboration is made of the consequences of reactant or product adsorption for the shape and situation of d.c. polarographic waves at the dropping mercury electrode.
TL;DR: Differential pulse and d.c. sampled polarography have been used to investigate the reduction of ferrous and manganous ions from both hypolimnetic lake water and a synthetic solution of comparable alkalinity and ionic strength as discussed by the authors.
TL;DR: In this paper, the electrolytic reduction of vanadyl acetylacetonate in acetonitrile solution was investigated by means of conventional and AC polarography, cyclic voltammetry and controlled potential electrolysis.
Abstract: The electrolytic reduction of vanadyl acetylacetonate in acetonitrile solution was investigated by means of conventional and AC polarography, cyclic voltammetry and controlled-potential electrolysis A well-defined polarographic cathodic wave was obtained in a solution containing excess acetylacetone The wave-form was outwardly a single step with two-electron transfer However, logarithmic analysis revealed that it consists of two steps The first step is slightly irreversible, being accompanied by V–O bond breaking, and the second one is controlled by the rate of coupled chemical reactions The reaction mechanism is discussed in detail The reversible half-wave potentials of the species [VO(acac)2] and [V(acac)3] were determined to be −193 and −178 V vs Ag/01 M AgClO4, respectively, from the logarithmic analysis
TL;DR: In this article, an exact equation for the instantaneous catalytic current in pulse polarography was derived, which coincides with that of Koutecký for normal polarography, when the time elapsed without voltage application to the mercury drop is null.
TL;DR: In this article, the processes of reduction and reoxidation of iron(II) ions in neutral thiocyanate media have been investigated by cyclic and stripping voltammetry.
TL;DR: In this article, a general treatment of voltammetry of equilibrium complexation reactions at an electrode expanding in accord with any power law, the stationary electrode and the dropping mercury electrode being special cases.