Simultaneous determination of (+)-catechin and (-)-epicatechin in cacao and its products by high-performance liquid chromatography with electrochemical detection.

A fast single-step extraction procedure and HPLC with electrochemical detection (ECD) in the oxidative mode has been used for the simultaneous, quantitative determination of (+)-catechin (CA) and (-)-epicatechin (EC) in cacao and its products. A UV detector measuring at 280 nm was also used in-line for comparison purposes. The samples were extracted with methanol and applied directly to the reversed-phase column of the HPLC. The high sensitivity of the ECD allowed operation at a low voltage (+0.5 V), but with a high sensitivity for the readily oxidizable CA and EC, thus reducing baseline noise. As a result, ECD had a better sensitivity and resolution than UV detection for the simultaneous quantitative determination of CA and EC in cacao and its products.