Oxidation—Reduction Potentials Measured with the Dropping Mercury Electrode. III. Polarographic Study of Quinhydrone in Buffered and Unbuffered Solutions1

1940 ◽  
Vol 62 (9) ◽  
pp. 2434-2441 ◽  
Author(s):  
Otto H. Müller
1962 ◽  
Vol 15 (4) ◽  
pp. 729 ◽  
Author(s):  
VS Srinivasan ◽  
AK Sundaram

The polarography of lead in the iodide medium has shown that an irreversible wave is obtained at moderate concentrations of lead, whereas at high concentrations two waves are obtained and at low concentrations a single reversible wave is obtained. This explains the irreversible waves obtained by the earlier workers who have mainly worked in the region of 0.4mM of lead. From a study of the effect of the head of mercury, temperature, etc. it is shown that the second wave is an adsorption wave resulting from the adsorption of lead iodide complexes at the dropping mercury electrode.


1979 ◽  
Vol 44 (2) ◽  
pp. 448-455 ◽  
Author(s):  
Emil Paleček ◽  
Sianette Kwee

The influence of adsorption of DNA on its double-stranded (ds) structure was studied with the aid of hanging mercury drop electrode (HMDE) in neutral media. Changes in DNA reducibility followed by linear sweep voltammetry served as an indication of the DNA conformational changes in the electrode surface. It has been shown that, due to contact of ds DNA with the electrode for periods many times longer than those which can be reached at the dropping mercury electrode, extensive surface denaturation of DNA can be detected only in a narrow potential range around -1.2 V. At potentials more negative than this region neither surface denaturation nor blocking of the electrode by the reduction product were observed. On the other hand, interaction of the denatured DNA with the mercury surface under the same conditions, resulted in blocking of the electrode surface by the reduction product. In agreement with the previous studies in acid media similar blocking of the surface was observed at pH 5 both with thermally denatured and ds DNAs. On the basis of the experimental data the following conclusions have been drawn: i) in neutral media the course of interfacial events of DNA is strongly dependent on DNA conformation and differs from the course suggested for acid media; ii) the deduction concerning the behavior of ds DNA on the electrode in neutral media made by other authors on the basis of their measurements in acid media is not justified.


1962 ◽  
Vol 15 (4) ◽  
pp. 734 ◽  
Author(s):  
VS Srinivasan ◽  
AK Sundaram

An a.c. polarographic study of the lead-iodide system is described. Three peaks are obtained. The second and third peaks are proved to be due to a combined tensammetric-polarographic process.


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