Simple Electrochemical Determination of Surface-Active Substances in Natural Waters

Figure 2

𝑖_ac-𝑡 curves for different concentrations of (a) T-X-100: (1) 0 mgL⁻¹, (2) 0.0237 mgL⁻¹, (3) 0.0594 mgL⁻¹, (4) 0.0951 mgL⁻¹, (5) 0.143 mgL⁻¹, and (6) 0.190 mgL⁻¹ and (b) humic acid: (1) 1.65 mgL⁻¹, (2) 4.4 mgL⁻¹, (3) 6.6 mgL⁻¹, (4) 10.45 mgL⁻¹, and (5) 16.5 mgL⁻¹. Supporting electrolyte: 0.55 M NaCl. Peak-to-peak amplitude 10 mV, frequency 75 Hz. Each point represents a freshly formed Hg drop.

(a)

(b)