Page 98 - Analytical Electrochemistry 2d Ed - Jospeh Wang

3-5 STRIPPING ANALYSIS 83

FIGURE 3-17 Adsorptive stripping potentiograms for 0.5 ppm calf-thymus DNA following
different adsorption times of 1±150 s (curves a±f) (Reproduced with permission from
reference 38.)

sensitive measurements can thus be performed, as illustrated in Figure 3-18 for the
direct determination of subnanomolar concentrations of iodide in seawater.
Anions (e.g., halides) that form insoluble silver salts can be measured at a rotating
silver disk electrode. In this, the deposition and stripping steps involve the reaction

Ag ‡ X „ AgX ‡ e X ˆ CI ; Br 3-30†
Copper-based electrodes can also be employed for the same task.