Study on its variability of determination method of Total Flavones of total flavones of Hippophae rhamnoides and Ginko Biloba Extract

Objective: To determine the total flavones of Hippophae rhamnoides(TFH)and Ginko Biloba Extract(GBE),and to study whether isorhamnetin can be replaced by quercetin with quercetin and isorhamnetin as reference materials.Methods: Quercetin and isorhamnetin were selected as reference material and Aluminum chloride spectrophotometry was used to determine the total flavones of Hippophae rhamnoides(TFH)and Ginko Biloba Extract(GBE).Results: To convert into quercetin,the total flavones of TFH was 8.90%,the total flavones of GBE was 4.41%;To convert into isorhamnetin,the total flavones of TFH was 16.8%,the total flavones of GBE was 8.25%.Conclusion: The total flavones of the same sample is quite different by using different reference materials.As reference material,isorhamnetin can not be simply taken place by quercetin.