Improvement in the determination of food additive dyestuffs by capillary electrophoresis using β-cyclodextrin

Abstract The determination of seven food additive dyestuffs was investigated by capillary electrophoresis. When β-cyclodextrin was introduced into the carrier electrolyte, the apparent mobility was increased, leading to 9.5–39% lower migration times due to the increase in the solute's mass after inclusion complex formation. The reproducibility and peak shape were improved because interaction between the solute and the capillary wall was alleviated. The effects of β-cyclodextrin on the migration time, elution order, peak shape and reproducibility of food additive dyestuffs are discussed in terms of providing a considerable advantage for determining organic anions by capillary electrophoresis. Sequential injection of dyestuffs and β-cyclodextrin into a capillary electrophoresis column was found to be a simple and rapid method for a qualitative comparative study of inclusion complexation phenomena.