Determination of pyrroloquinoline quinone by capillary zone electrophoresis

A new method for the determination of pyrroloquinoline quinone by capillary zone electrophoresis has been developed. Separation conditions have been o ptimised with the respect to different parameters including pH and ionic st rength of the background electrolyte, separation voltage and temperature of the capillary. A buffer consisting of 50 mM beta-alanine-HCl pH 3.0 was fo und to be the most suitable electrolyte for this separation. An applied vol tage of 25 kV (negative polarity) and a temperature of 25 degrees C gave th e best analysis of pyrroloquinoline quinone. The linear detection range for concentration versus peak area for the assay is from 5 to 500 mu M (correl ation coefficient 0.9998) with a detection limit of 0.1-0.2 mu M. The inter -day reproducibility of the peak area was 2.5% and the inter-day reproducib ility of the migration time was below 0.18%. (C) 2000 Elsevier Science BN. All rights reserved.