Separation/determination of flavonoids and ascorbic acid in rat serum and excrement by capillary electrophoresis with electrochemical detection.

A capillary electrophoresis with electrochemical detection was developed for the simultaneous determination of three flavonoids (naringenin, rutin, quercetin) and ascorbic acid. It was found that naringenin, rutin, quercetin and ascorbic acid were well separated within 5 min in borate buffer solution (pH 8.6, 24 mM). The detection limit was 1.0 μM for naringenin, 8.0 μM for rutin, 2.0 μM for ascorbic acid and 0.5 μM for quercetin. The protocol was successfully applied for the determination of the analytes in rat serum and excrement. Recovery results ranged from 90.9 to 108.6%.