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

Figure 6

Chromatograms acquired for blank solution (a), gallic (b), vanillic (c), caffeic (d), ferulic (e), and p-coumaric acids (f) and for the mixture of standard solutions of the analytes (g). Potential: 0.80 V (versus Pd). Mobile phase: 0.20 mol·L⁻¹ acetate buffer (pH 5.0)/ultrapure water (80 : 20 v/v). Isocratic elution. Mobile phase flow rate: 0.8 mL·min⁻¹. CA: caffeic acid (3.60 mg·L⁻¹); FA: ferulic acid (3.88 mg·L⁻¹); GA: gallic acid (3.40 mg·L⁻¹); p-COA: p-coumaric acid (3.28 mg·L⁻¹); VA: vanillic acid (3.36 mg·L⁻¹).