High Performance Liquid Chromatographic Determination of Phenolic Compounds in Propolis

Purpose: To develop a simple, precise and rapid high-performance liquid chromatographic technique coupled with photodiode array detection (DAD) method for the simultaneous determination of rutin, quercetin, luteolin, genistein, galangin and curcumin in propolis.
Methods: Ultrasound-assisted extraction was applied to isolate six antioxidant phenolic compounds from propolis samples. Chromatographic separation was performed using an Eclipse XDB-C18 column (150 mm×4.6 mm, 5 μm) by isocratic elution at 25 °C. The mobile phase consisted of phosphate buffered saline (pH = 4.5) and methanol (40/60, v/v). The flow rate was set at 0.8 ml/min and the effluent was monitored using a DAD set at 260 nm.
Results: Excellent linear correlation coefficient was observed in the range of 0.9977 to 0.9997. The reproducibility of the method was 1.58 % (RSD) and accuracy was confirmed with average recovery ranging from 95.71 to 104.26 %. Six antioxidant phenolic compounds in propolis samples were successfully determined within 50 min.
Conclusion: The proposed isocratic LC method gave good separation and accurate determination of rutin, quercetin, luteolin, genistein, galangin and curcumin in propolis. The proposed method showed good sensitivity, linearity, repeatability and accuracy.

Keywords
Propolis; Rutin; Quercetin; Luteolin; Genistein; Galangin; Curcumin; HPLC