Capillary zone electrophoresis of coniferyl alcohol oxidation products.

Capillary zone electrophoresis (CZE) was developed for the quantitative determination of dimers obtained by horseradish peroxidase-catalyzed oxidation of coniferyl alcohol. The influence of pH, electrolyte concentration, applied voltage, and temperature on CZE performance was investigated, resulting in an efficient and rapid separation. Coniferyl alcohol-derived dimers were directly analyzed from their reaction mixtures, without any extraction or derivatization step. In addition, these dimers were analyzed within 14 min, a substantially shorter time than is required for the HPLC method or the conventional capillary gas chromatography of their silylated derivatives. Standard deviations between injection replicates were in the 0.4-0.7% range for migration times and in the 1.8-5.1% range for relative normalized peak areas. The method could therefore be successfully applied to follow the peroxidase-catalyzed oxidation of coniferyl alcohol.