Abstract
In consideration of the analysis of Qinghaosu in plant extracts, medicine and biological fluids, UV-absorption and high pressure liquid chromatographic characteristics were investigated after a modification which makes it UV-detectable. The influence of the pH value on the UV-spectrum and extinction of the modified Qinghaosu was examined. Using a UV-detector, the HPLC behaviours of the modified compound were studied. The influence of inorganic salts and buffer mixtures, as well as of methanol in the mobile phase on retention, detection sensitivity, and detection linearity were investigated. By means of preconcentration directly on the column, a detection sensitivity of 10-9 g/ml can be attained. The present method, which utilizes the UV-character of Qinghaosu in HPLC, was practically applied to the determination of Qinghaosu in flowers and leaves of Artemisia annua L.