Fig. 5. Squarewave voltammograms recorded in 0.04 mol L−1 BR buffer: ethanol (80:20,
v:v) mixture (pH 4.0) in presence of 0.30 mmol L−1 CTAB (curve a). Curve b corresponds
to SWV after the addition of the sun-block sample. (c–f) Successive standard additions of
OCR, BENZO-3 and OMC. Experimental conditions: Eacc=−0.4 V, tacc=30 s; f=90 Hz;
Esw=20 mV; ΔEs=4 mV.