A Novel Method For The Extraction Of Flavonoid Compounds From Bee Pollen

This study established a new method based on soxhlet extraction and matrix solid-phase dispersion for sample preparation,which was named soxhlet-assisted matrix solid phase dispersion(SA-MSPD).To establish the optimal method of SA-MSPD,this study examines the parameters which affect the extraction yield.And this method was applied to the extraction and detection of flavonoid compounds in bee pollen.Part 1:SA-MSPD was developed to extract flavonoids from rape(Brassica campestris)bee pollen.Extraction parameters including the extraction solvent,the extraction time,and the solid support conditions were investigated and optimized.The best extraction yields were obtained using ethanol as the extraction solvent,silica gel as the solid support with 1:2 samples to solid support ratio,and the extraction time of one hour.Comparing with the conventional solvent extraction and soxhlet method,our results show that SA-MSPD method is a more effective technique with clean-up ability,shorter extraction time,higher extraction yield,less sample and solvent consumption.In the test of six different samples of rape bee pollen,the extracted content of flavonoids was close to 10 mg/g.Part 2:SA-MSPD with acidolysis was developed to analyze flavonoid aglycones from bee pollen.Extraction parameters including the content of acid,the extraction time and the soild support conditions were investigated and optimized.The best extraction yields were obtained using 60%ethanol and 0.30 mol/L hydrochloric acid as the extraction solvent,silica gel as the solid support with 1:2 samples to solid support ratio,and the extraction time of two hour.Comparing with the conventional solvent extraction,our results show that SA-MSPD method is a more effective and new technique with extraction and acidolysis steps at the same time,reducing the operation steps and time.In the test of thirty-nine different samples of bee pollen,the results show that different types of bee pollen have different kinds and contents of flavonoid aglycones,which can be used for distinguishing different types of bee pollen.