Determination of Phenolic Acids in Sugarcane Vinasse by HPLC with Pulse Amperometry

Figure 2

Cyclic voltammograms of studied polyphenols in 0.1 mol·L⁻¹ acetate buffer (pH 5.0) and potential range of −0.15 to 1.35 V. (a) Caffeic acid (180.2 mg L⁻¹); (b) ferulic acid (194.2 mg·L⁻¹); (c) p-coumaric acid (164.2 mg·L⁻¹); (d) gallic acid (170.1 mg·L⁻¹); (e) vanillic acid (168.2 mg·L⁻¹). Scan rate: 50 mV·s⁻¹.

(a)

(b)

(c)

(d)

(e)