Studies In Applications Of Hyphenated HPLC-UV-ELSD For Analysis Of Traditional Chinese Medicines

High-performance liquid chromatography (HPLC) is one of the most important means for the quality analysis of traditional Chinese medicines (TCMs), while ultraviolet detector (UVD) and evaporative light-scattering detector (ELSD) are two most important detectors in HPLC instruments. As the TCM systems of analytical interest become more complex, neither UVD nor ELSD is capable to fulfill the analyzing requirements alone, thus hyphenated HPLC-UV-ELSD is increasingly employed for instrumental analysis of TCMs.In this thesis, the principles, current improvements and applications of ELSD were reviewed first. Analyzing methods for a botanical preparation, Fufang Danshen Tablet (FDT) and a cruel herb, Radix Ophiopogonis were established by HPLC-UV-ELSD, basing on quantitative determination of marking compounds and chromatographic chemical fingerprinting, respectively. The main contents and outcomes of this thesis are listed as follows:1. An HPLC method was constructed for the simultaneous determination of the active components derived from Radix Salvia miltionhiza and Panax notoginseng in FDT products. UV at 280 nm was utilized for determination of danshensu, protocatechuic aldehyde and salvianolic acid B, UV at 254 nm was utilized for determination of cryptotanshinone, tanshinone I and tanshinone IIA, and ELSD was utilized for determination of notoginsenoside R₁, ginsenoside R_g1 and ginsenoside R_b1. The precision, repeatability, stability and accuracy of the established method were well-validated and proved to be satisfactory. The method was successfully applied for the quantitative determination of the components in 10 batches of FDT products.2. A binary HPLC-UV-ELSD fingerprinting for Radix Ophiopogonis was established for the first time. The chemical characteristics of homoisoflavonoids, saponins and other non-saccharide components could be simultaneously revealed. A data processing method corresponding to HPLC-UV-ELSD fingerprinting was also proposed, in order to integrate the information of the two sub-fingerprints, remove redundant data and adjust the responsing magnitudes of the two detectors. Using the established method, fingerprints of 14 Radix Ophiopogonis samples and 2 Radix Liriopes samples were obtained, and the similarities of the Radix Ophiopogonis samples were calculated.The results of the present work indicated that the UVD and the ESLD provided diverse, complementary performances. By hyphenate UV-ELSD, much more information could be obtained. Considering that many TCMs simultaneously contain chromophoric and non-chromophoric components, HPLC-UV-ELSD is predictably playing a more important role in the analysis of TCMs in the future.