Figure 5.

Anodic stripping square wave voltammograms of Ar-purged sample in the absence and presence of 0.5 μM Cu(II). a) 2.0 μM ZnS model solution (0.1 M KCl, pH 7.6). The deposition step occurred for 10 s at -1.3 V. b) Filtered diffuse-flow vent fluid from Tow Cam (TC-159-2), which contained approximately 0.1 μM labile Zn²⁺ prior to Cu(II) addition. The deposition step occurred for 120 s at -1.3 V. The half-wave potentials (vs. SCE) for the metal analytes are -1.0 V for Zn²⁺ and -0.18 V for Cu²⁺.