The Study Of Extracting Quercetin And HPLC Analysis

Analytical chemistry plays an increasingly important role in traditional Chinese medicine research. The applications of analytical chemistry in traditional Chinese medicine research involve the extraction, separation and characterization of the effective constituents in the medicines.In this thesis, we studied the extraction and separation methods of quercetin .Two new extraction methods were used to extract the effective constituents from traditional Chinese medicines were developed: ultrasonic technology and ultrahigh-pressure extraction. The influence of extraction variables on extraction efficiency of quercetin was investigated. Compared with the conventional extraction method, the extraction time is shorter when new methods were applied. The ultrasonic extraction technique and ultrahigh-pressure extraction were shown to be very efficient in the extraction of quercetin from Syringa oblata Lindl leaves.The determination of the quercetin in Syringa oblata Lindl leaves were performed by high performance liquid chromatography (HPLC). In this study, the conditions of HPLC, such as components and ratio of the mobile phase,detection wavelength,flow rate,column temperature and components of the buffer solutions were examined in detail. The experimental results for recovery and precision determination showed that HPLC is an accurate, fast and highly efficient method to separate and determine the effective constituents quercetin from traditional Chinese medicine.The method was applicable for the quantification of commercial tablets. The HPLC were shown to be more efficient in the detection of quercetin from Syringa oblata Lindl leaves than HPCE.