Determination of flavonoids in propolis-rich functional foods by reversed phase high performance liquid chromatography with diode array detection

A method of reversed phase high performance liquid chromatography (RP-HPLC) coupled with a diode array detector (DAD) was developed for the simultaneous determination of 10 common flavonoids in propolis-rich functional foods. Flavonoids in a sample were extracted with methanol in an ultrasonic bath for 15 min and then chromatographically separated on a C18 column. The binary mobile phase, composed of water with 1% tetrahydrofuran (pH = 2.5) and acetonitrile, was used for gradient elution. The proposed method revealed a good linearity between the peak area of each analyte and its concentration. The intra- and inter-day relative standard deviations (RSDs) were less than 1.90% and 4.91%, respectively. Recoveries were within the range of 84.2–118.7%. LODs and LOQs were 0.043–0.232 μg mL−1 (S/N = 3) and 0.007–0.039 mg g−1 (S/N = 10), respectively. The proposed method provided a simple and rapid routine analysis of common flavonoids in propolis-rich functional foods which are popular on the market nowadays.