A study on the determination of the total flavonol glycosides in health food / 预防医学

ABSTRACT

Objective To develop a HPLC method for the determination of the total flavonol glycosides in health food by acid hydrolysis. Methods The sample was extracted by methanol and was hydrolyzed into 3 aglycones by acid hydrolysis. They were quercetin, kaempferide and isorhamnetin. Chromatographic separation was carried out by the method of HPLC. The content of total flavonol glycosides was calculated. Results Methanol -25% hydrochloric acid solution (41) was added into selected samples, then 85 ℃ water bath heating and refluxing were conducted for 30 min. Optimum chromatographic conditions were as follows. Chromatographic column ODS C18 (150 mm ×4.6 mm,5μm) . Mobile phase used methanol-0.6% phosphoric acid (4753) . Column temperature was set at 35 ℃. Detection wavelength was 360 nm. The linear ranges of quercetin, kaempferide and isorhamnetin were (4.766-95.52) μg/mL(r=0.9991) , (5.052-101.0) μg/mL (r=0.9994) and (2.027-48.66) μg/mL (r=0.9994) respectively. The relative standard deviation of the samples was 0.57%. The recovery rate was 98.25% (RSD=3.82%), 99.81% (RSD=3.31%) and 101.8% (RSD=4. 86%) . The detection limits of quercetin and kaempferide were both 0.50 μg, while Isorhamnetin was 0.80 μg, the total flavonol glycosides was 4.52 μg. The content of total flavonol glycosides detected by this method was lower than the content of the total glavonoids detected by the method provided by technical specification for inspection and evaluation of health food (2003 Edition) . Conclusion This method proved to be simple, stable and had strong repeatability and could be used for the determination of total flavonol glycosides in health food.