Sudarshan Lal

Response Characteristics of the Orion Potassium Ion Selective Electrode

Abstract The Orion potassium ion selective electrode (92–19) has been evaluated in terms of Nernstian response, selectivity, anion, and pH effects. The response is slightly less than Nernstian and a linear calibration curve is obtained over the concentration range 10−4 to 10−1 M potassium, The calculated selectivity ratio for potassium over sodium depends on the relative concentrations of sodium and potassium. Slight anion effects are noted with the most significant occurring with iodide, hydroxide, chromate, and oxalate. Tetraphenyl borate ion causes a large negative potential shift and this effect appears to render the electrode only moderately useful for titrations with this reagent.

Potentiometric studies with a liquid ion-exchange lead-selective electrode

Abstract The performance of the Orion liquid ion-exchange lead-selective electrode has been determined in terms of the working concentration range of lead ions, its selectivity to other ions, its response time, the effective pH range in which it can be used, and its use in potentiometric titrations. The electrode exhibits relatively high response to monovalent cations and can be used in the potentiometric titration of alkali metals, thallium(I), silver(I), and ammonium ions with sodium tetraphenylboron, as well as for titrations of lead(II) with various solutions.

Measurement of solution streaming in polarographic maxima of the second kind

Summary A detailed procedure for the measurement of the speed of solution streaming in maxima of the second kind is described. The solution velocities increase to maximal values at the drop surface and different velocities are found in various regions around the drop. The effect of varying flow rate of mercury, concentration of supporting electrolyte and presence of a surfactant on these velocities is reported.

Characteristics of a mixed positive maximum

Summary The positive maximum in the reduction of copper(II) in sodium sulphate has been studied in purified solutions in the absence of resistance control of the current. It was found that the first-kind maximum ceased well before the p.z.c. under some conditions, substantiating the dieas proposed concerning cessation of streaming. The balance between first- and second-kind streaming was studied as a function of the concentrations of depolarizer and of support-electrolyte and of the rate of flow of mercury, giving support to the theory that could not be obtained with previously published work where the current was controlled by the resistance of the circuit.

Polarographic maxima in the cobalt—8-hydroxyquinoline system

Abstract The behavior of the polarographic maximum of the cobalt—8-hydroxyquinoline system in ammonia-ammonium chloride buffer has been studied with regard to general morphology, effect of mercury flow rates, current—time curves and streaming patterns under carefully controlled conditions. The maximum appears to be an adsorption-controlled catalytic maximum. Current—time curves and streaming observations provide useful information in its characterization. Difficulties in distinguishing the first-kind negative maxima from catalytic maxima are discussed.

Polarographic Maxima of the Second Kind: Dependence on Concentration, Temperature, and Time

Abstract Data are reported concerning the effects of concentration, temperature, and time on the magnitude of the current flowing in the presence of a polarographic maximum of the second kind. The current is a non-linear function of concentration; this is explicable on the basis of recent theory, and contrasts with statements and data commonly found in the literature. The temperature-dependence of the current is of the same magnitude as expected for diffusion-controlled currents; this is at variance with an earlier report in the literature. The current-vs.-time behavior shows a previously unreported discontinuity.

Polarographie von Indium(III) in Alkali-und Erdalkalinitratlösungen

Polarographic behavior of Indium(III) in several nitrates of varying concentrations has been studied and resuts interpreted in the light of factors viscosity, diffusion coefficients and ion solvation. The apparent rate constants were determined byDelahays treatment which revealed its quasireversible behavior.ZusammenfassungEs wurde das polarographische Verhalten von Indium(III) in verschiedenen Nitraten in Abhängigkeit von der Konzentration untersucht. Die Ergebnisse wurden unter besonderer Beachtung der Faktoren Viskosität, Diffusionskoeffizienten und Ionensolvatation interpretiert. Die scheinbaren Geschwindigkeitskonstanten wurden nach dem Verfahren vonDelahay bestimmt und ein quasireversibles Verhalten festgestellt.

Polarographic Study of Lead-Tropolone Complexation

Abstract A.C., D. C. and derivative pulse polarography of lead-tropolone complexes has been studied. It has been shown that the application of usual treatments for complexation in d. c. polarography are invalid in this system, where the irreversible wave in presence of the ligand is a composite step. It seems generally advisable to apply derivative pulse or a.c. polarography before using non-reversible d.c. steps for evaluation of K and p.