Page 39 - Analytical Electrochemistry 2d Ed - Jospeh Wang

24 FUNDAMENTAL CONCEPTS

FIGURE 1-15 Electrocapillary curves for different electrolytes showing the relative
strength of speci®c adsorption. (Reproduced with permission from reference 5.)

potential passes through the E pzc . Experimental electrocapillary curves have a nearly
parabolic shape around E pzc . Such a parabolic shape corresponds to a linear change
of the charge with the potential. The deviation from a parabolic shape depends on
the solution composition, particularly on the nature of the anions present in the
electrolyte. In particular, speci®c interaction of various anions (e.g., halides) with the

FIGURE 1-16 Electrocapillary curves of background (j), ethynylestradiol ( ), b-estradiol
(m) and morgestrel (r). (Reproduced with permission from reference 12.)