Simultaneous quantitation of 5- and 7-hydroxyflavone antioxidants and their binding constants with BSA using dual chiral capillary electrophoresis (dCCE) and HPLC with fluorescent detection

Abstract In this article we present two novel uses of the sensitive techniques HPLC fluorescence and dCCE for both the quantitation and binding studies of the 5- and 7-HFs extracted from the plant Alfalfa with Albumin. Ultrasonic extraction method as an extra energy source is used to enhance the extraction efficiency and speed up. The two antioxidants could be easily separated and quantified after a 10.0-min run time. Multiple calibration curves for their analysis exhibited consistent linearity and reproducibility in the range of 0.20–2.00 mg L −1 for 5-HF ( r >0.9979) and 0.01–0.10 mg L −1 for 7-HF ( r >0.9999). Limits of Detection were 0.500 µg L −1 and 0.025 µg L −1 for 5-HF and 7-HF respectively. Lower Limits of Quantification were 131.600 µg L −1 for 5-HF and 6.579 µg L −1 for 7-HF. Inter-assay imprecision was 5  L mol −1 and 2.390–2.500×10 5  L mol −1 for 5-HF and 7-HF respectively.