Phenol hydrodynamic voltammogram

The hydrodynamic voltammograms of picric acid and p-nitro-phenol depicted in Figure 12 illustrate the influence of mechanism on the detection process. If the detector potential is set at the potential on the plateau of the voltammogram of p-nitro-phenol, both compounds are detected. If the potential is set at the plateau of the first wave of picric acid, it alone is detected. At more negative potentials the unit response for the polynitroaromatic compounds will be greater than the response for mononitroaromatic compounds since more electrons are involved in the electrochemical reduction of polynitroaromatics. 

The variation in peak height for the phenol signal as a function of the potential applied to the electrochemical cell is shown by the hydrodynamic voltammogram in Fig. 4. Maximum sensitivity for phenol detection is achieved at a potential of +850 mV versus Ag/AgCl, or greater. Our experiments were conducted at a potential of +870 mV. 

Fig. 4. Hydrodynamic voltammogram of 7.0 x 10 M phenol. See conditions for Fig. 3. (From Wehmeyer et al., 1983, with permission.)...

Figure 2.5 Hydrodynamic voltammograms generated by repeat injections of physostigmine ( ) and its hydrolysis product, the phenol eseroline (o). Chromatographic conditions Column 250 x 4.6 mm(i.d.) Spherisorb S5W Eluent methanol-aq. ammonium nitrate (1.0 mol L , pH 8.5) (90 + 10) Flow rate 0.75 mL min Detection glassy carbon electrode (GCE). The half-wave potentials (from the fitted curves) were - -0.69 V and - -0.21 V vs Ag/AgCl.

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