K S G Doss
Articles written in Proceedings – Section A
Volume 26 Issue 3 September 1947 pp 197-202
The best conditions for determing rubin numbers have been worked out. The rubin number is defined as the number of milligrams of the protective colloid which when present in 10 c.c. of a 0·002% congorubin solution of pH 5·2 and electrolyte concentration of 0·02 N produces 26.5% blue colour on addition of 1 c.c. of 10% solution sodium chloride. The rubin number of a protective colloid can be accurately determined with the help of an Hellige colorimeter employing Gillespie’s technique.
Volume 27 Issue 6 June 1948 pp 411-420
Volume 32 Issue 6 December 1950 pp 402-408
A new method for the determination of rubin numbers has been advanced. The previous method based on the measurement of the blue colour was discarded as the blue dye was found to be in suspension. The rubin number of a protective colloid is defined as the number of milligrams of that colloid which when present in 10 c.c. of 0·002% congo rubin solution of pH 5·1 produces 9·0 Lovibond units of red colour in a 0·6″ cell on addition of 1 c.c. of 10% sodium chloride and centrifuging. The results obtained by this method in the case of starch, casein and albumin show the same trend as the results of the earlier methods.
Volume 33 Issue 5 May 1951 pp 298-304
A method has been described for measuring small alternating currents. This has been applied for studying the a.c. currents induced in a dropping mercury electrode system containing nickel ions when subjected to a pulsating field at different frequencies of the field. This system has revealed interesting features which are different from the systems investigated by the previous workers.
Volume 34 Issue 4 October 1951 pp 229-235
It has been shown that the redoxokinetic effect is a general phenomenon. The effect of redox ratio on the redoxokinetic potential has been discussed.
Volume 34 Issue 4 October 1951 pp 263-271
The theory of the redoxokinetic effect has been formulated for smale a.c. fields. One interesting result coming out of the theory is that the redoxokinetic potential is proportional to the square of the a.c. field. Experiments have been done with the ferrous-ferric system which confirm the above theoretical result. From the observed values of the redoxokinetic potential it has been possible for the first time to get a general method for the d-l termination of “
Volume 35 Issue 1 January 1952 pp 27-33
Volume 35 Issue 1 January 1952 pp 45-45 Erratum
Volume 35 Issue 4 April 1952 pp 173-177
Volume 36 Issue 5 November 1952 pp 343-354
1. A new technique has been described for studying the mechanism of action of pH on spreading of invertase. The film of invertase on 0·1 N HCl pH 1·0 was transferred to buffer solution pH 3·0 after washing it with distilled water. In the second experiment the film was spread on buffer of pH 3·0 and brought to 0·1 N HCl pH 1·0.
2. Sodium metaphosphate and trichloracetic acid have a contracting effect on the film at low pH but at higher pH the spreading is increased because the tendency of the film to dissolve at higher pH is reduced by these precipitants.
3. Ammonium sulphate at low pH has got a contracting effect but at higher pH this also increases the spreading. Barium chloride however increases the spreading considerably.
4. Invert sugar has been found to have no effect on the spreading of invertase.
5. Heating of invertase makes it completely inactive but the spreading is found to increase.
6. Treatment of the invertase with formaldehyde causes a decrease in spreading.
Volume 36 Issue 6 December 1952 pp 493-500
It is found that the differential capacity of the dropping mercury electrode is affected mainly in two ways by added surface-active substances. At about the electrocapillary zero there is a strong lowering of the capacity due to adsorption of surface-active substances. At some higher cathodic potential there is enormous increase in differential capacity leading to a maximum and is followed by a sharp fall in the capacity; the latter is due to the desorption taking place more or less sharply at the higher cathodic potentials. The theory of the phenomenon has been formulated.
Volume 37 Issue 1 January 1953 pp 63-67
A detailed study has been made of the kinetics of inactivation of invertase at 25°C. in acid media. The results indicate the existence of two processes, one of them being very fast and coming up at comparatively high pH values and the other coming up at lower pH.
Volume 48 Issue 1 July 1958 pp 43-48
The application of Delahay’s theory of kinetic polarographic currents as applied to the reduction of pyruvic acid has been examined. It is shown that the agreement between Delahay’s theory and the available data is more satisfactory, if one assumes that the current is controlled by the rate of the reaction between pyruvate ion and water molecule forming pyruvic acid and hydroxyl ion, than when one assumes the mechanism suggested by the earlier workers involving the rate of reaction between pyruvate ion and hydrogen-ion, both from the point of view of the magnitude of the diffusion current as well as its pH dependence. The results give an indication of the latter reaction being sluggish due to the activation energy requirements.
Volume 49 Issue 3 March 1959 pp 129-135
The effect of sodium dioctysulphosuccinate on the differential capacity of dropping mercury electrode in 0.1 M KCl solution is studied. It is observed that at the desorption potential, vigorous directed movement of liquid occurs at the mercury-aqueous interface. This movement is shown to be responsible for the desorption peak in the differential capacity-potential curve.
The cause of the directed movement is further examined. Arguments are given to support the ideas of Doss and Kalyanasundaram, that the movement is caused by the emerging surface of mercury having a different interfacial tension from that of the older surface, and that the shielding effect of the capillary postulated by Stackelberg does not appear to play an important part either in the production of the desorption peak or the polarographic maxima.
It is found that the directed movement of liquid occurs although to a less extent at potentials far removed from the desorption potential. This results is of great significance in that it points at the importance of looking for such movements before interpreting quantitatively the data obtained with a dropping mercury electrode.
Volume 66 Issue 2 August 1967 pp 69-76