Instrumental Methods of Derivative Polarography

First‐ and Second‐Order Derivative Polarography/Voltammetry for Reversible, Quasi‐Reversible, and Irreversible Electrode Processes

“…The method is new applied to systems of simple heterogeneous electron transfer without coupled reactions, but to the systems which are complicated in other way by a slow electron transfer. Several experiments were carried out to verify the Theory Current (i) as a function of the applied potential (E), under semi-infinite linear diffusion conditions, can be expressed by the following relationship for a simple reversible electron-transfer process t8' 29 0 + ne---> R (Nernstian) [1] i(E) = id [1/(1 + e)] [2] where id = nFAD~/2Co/(=t ) ~/2 (the diffusion-controlled current) [3] e = exp (nFE/RT) [4] and E is an applied potential with respect to the reversible polarographic half-wave-potential, E~/2 (rev) or Eh. Other parameters and variables have their usual meanings.…”

Modified linear null-point potentiometry

“…), the lower closed end of which is the Corning No. 7930 porous Vycor glass (6). The other design, shown in Figure 1, is simply a plug of the porous Vycor rod (3 mm long X 3 mm diameter) connected to 3 mm o.d.…”

“…However, both methods usually " Sample volume = 0.1 ml. 6 Average of graphical and computer evaluations of the data (with the 95 % confidence limits).…”

Polarographic Theory, Instrumentation, and Methodology

“…Derivative Polarography. Kelley and Fisher (86) have made a detailed study of instrumental methods of obtaining derivative polarograms. The basic Leveque-Roth circuit was concluded to have a number of disadvantages, particularly-the R/C differentiating network which attenuates the signal while passing drop oscillations relatively unaffected; by the time a heavy integrating network is added, considerable distortion of the wave is produced.…”