VOLTAMMETRIC DETERMINATION OF CAFFEIC ACID IN ARNICA MONTANA

ABSTRACT

Arnica montana is a medicinal plant. Its biological activity is related to carboxyphenolic acids such as caffeic acid. This paper proposes a caffeic acid quantification method of Arnica montana tinctures by lineal sweep voltammetry with a platinum rotating disc electrode. Tinctures showed a number of electrochemical signals; two of them corresponding to caffeic acid oxidation. One of these signals was found to be controlled by a diffusion process and was used to quantify caffeic acid in the tinctures. The caffeic acid detection limit was established at 385 µg L⁻¹, and tincture concentration ranged from 161 to 265 mg L⁻¹.

Keywords:

• Voltammetry
• Caffeic acid
• Arnica montana
• Galenical preparations
• Natural medicine

ACKNOWLEDGMENTS

The authors gratefully acknowledge the support of Weleda A.G., Basel, Switzerland.