Using CoulArray Detector for Analysis of Natural Phenolic Compounds

Abstract

An HPLC method was developed for the analysis of phenolic compounds and flavonoids using a CoulArray detector with simultaneous recording of current responses of eight electrodes in series, with different applied potentials. The coulometric multielectrode detection offers a higher sensitivity and selectivity of determination compared with the single-electrode coulometric or fluorimetric detection. No special sample pretreatment is necessary and, because of the compatibility of the CoulArray detector with gradient elution, single-run analysis of phenolic antioxidants of different polarities is possible. In addition to the retention times, the ratios of the areas of the pre-dominant and post-dominant peaks to the area of the dominant peak can be used to improve identification of compounds. The method was used for analysis of 40 beer samples. Significant differences between the Czech and foreign beers were found in the occurrence and average concentrations of antioxidants.