Abstract: Objective: To determine cyanidin-3-O-glucoside (C3G) content in black soybean hulls grown in different regions of China by HPLC. Methods: The chromatographic separation was performed on Phenomenex Luna Su C18 (250 mm × 4.60 mm, 5 μm) column by gradient elution using 0.5% phosphoric acid solution as mobile phase A and water: acetonitrile (50:50, V/V) as mobile phase B at a flow rate of 0.8 mL/min. The column temperature was set at 30 ℃and the detection wavelength at 520 nm. Results: The developed regression equation of cyanidin-3-O-glucoside standard is: Y ＝ 2 × 107X － 33120 (r＝ 0.9998). A good linearity was shown in the range of 0.1041－1.041 μg. The average recoveries at three spike levels were 92.4%, 92.5% and 95.5%, respectively. The contents of cyanidin-3-O-glucoside in samples from Northeast China and Shandong, Hubei and Anhui provinces were in the range of 5.263－12.829 mg/g. Conclusions: The method is simple and reliable, and may be used for the quality control of black soybean hull from different geographic origins.

Key words: high performance liquid chromatography (HPLC), black soybean hulls, cyanidin-3-O-glucoside, content determination