Analysis of anthocyanins by capillary zone electrophoresis

A simple mixture of anthocyanins was analysed by CZE, using a standard silica capillary with a pH 8 borate running buffer. Generally, the anthocyanins separated according to the nature of the aglycone and degree of glycosylation. A concentrated injection solution was required for detection at 580 nm, due to the small proportion of coloured quinonoidal base in the anthocyanin equilibrium mixture at this pH, the small injection volume and the short detector path-length used in this technique. It was observed that the ability to maintain a satisfactory current during analysis was critically dependent on the pH of the injection solution.