Differential pulse voltammetry profiles

Figure 2.10 Differential pulse voltammetry profiles obtained at a platinum working electrode in a MeCN solution 5 x 1 4 in [Et3Bn]Cl and 0.1M in [Bu4N]C104. Dashed line, 3 M in the [Cun(ll)Nin](ClC>4)4 complex salt solid line, 1CT3M in both the [Cui1[(12)](C1C>4)2 and [NiI1[(ll)](C104)2 complex salts.

Figure 14. Differential Pulse Voltammetry profiles obtained for solutions of FcCH2N(CH3>2 of varying pH. The pH value was varied by adding standard acid to a basic solution of FcCH2N(CH3)2 unbuffered conditions). The less anodic peak corresponds to the oxidation of the FcCH2N(CH3)2 form, the more anodic peak corresponds to the oxidation of the FcCH2NH(CH3)2- form.

The metallocyclam moiety of the conjugate system 8 displays typical macrocydic properties for instance, in strongly addic solutions the Ni ion is not extruded from the tetra-aza ring and the system remains intact for weeks. Moreover, the conjugate molecule 8 discloses the expected two-electron redox activity, as documented by voltammetric investigations. Figure 3 reports the Differential Pulse Voltammetry profile of a MeCN solution 0.1 M in BU4NCIO4 and 5 x 10 M in 8. 

Figure 3. Differential Pulse Voltammetry profile obtained at a platinum microsphere for a MeCN solution of the conjugate system FcS02[Nill(cyclam)](C104)2, 8. The less anodic peak refers to the one-electron oxidation of the ferrocene moiety, the more anodic one corresponds to the Ni to Ni oxidation process taking place in the metallocyclam fragment.

Variation profile of the applied potential in differential pulse voltammetry. 

Differential pulse voltammetry This technique employs the potential-time profile as shown in Fig. 8 now the pulse height dE is kept constant (usually 25-100 mV) and the base potential is swept slowly with time. The current is sampled just before the application of the pulse (tsi) and just before the end of the pulse (132). Plot of the difference dl = I32 — against the potential at t3i yields the differential pulse voltammogram schematically shown in Fig. 8b. The peak of the reversible wave appears at E j2. 

FIGURE 1.65. Schematic representation of the principles of Differential Pulse Voltammetry (DPV). The input pulse profiles and the resultant current/potential profile are illustrated. Note that the potential waveform used in DPV is a composite entity comprising a staircase (or ramp) waveform superimposed on a constant-amplitude pulse sequence. The pertinent experimental parameters are indicated in the diagram. 

Fig. 18 Differential pulse voltammetry for G (blue), A (orange), T (violet) and C (magenta) on GC (A), graphite/GC (B), and rGO/GC (C) cone 10 pg/mL in PBS (0.1 M, pH 7) (reprint permission from ref. 54). (B) DVP profiles for pristine EG, anodized EG, GC and boron-doped diamond electrodes in 30 pg/ml double stranded DNA (left) and on anodized EG in 30 pg/ml double and single stranded DNA (supporting electrolyte 10 mM KCl/10 mM PBS, pH 7) (reprinted with permission from ref 63).

Fig. 2.33 Differential pulse voltammetry voltammetric profiles of AI versus staircase potential...

In hydrodynamic voltammetry current is measured as a function of the potential applied to a solid working electrode. The same potential profiles used for polarography, such as a linear scan or a differential pulse, are used in hydrodynamic voltammetry. The resulting voltammograms are identical to those for polarography, except for the lack of current oscillations resulting from the growth of the mercury drops. Because hydrodynamic voltammetry is not limited to Hg electrodes, it is useful for the analysis of analytes that are reduced or oxidized at more positive potentials. 

Fig. 4.3b. The profile of the potential pulse and current measurement in differential pulse stripping voltammetry...

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