| The content of oleuropein was usually determined by high performance liquid chromatography（HPLC） or gas chromatography（GC） method in previous studies.In this paper,a method for the determination of oleuropein in Olea europaea L.leaves was developed using a substraction of UV-Visible spectroscopy.With the standard rutin and oleuropein,two coloration systems including NaNO2-Al（NO3）3-NaOH and AlCl3 were both used.The total absorbance of total flavonoids and oleuropein was obtained at a wavelength of 510 nm in the former coloration system.In the latter coloration system,the absorbance of total flavonoid was obtained at a wavelength of 415 nm,but oleuropein was not detected at 415 nm in this system.According to the above absorbance properties,the content of oleuropein could be indirectly learned by substraction of the absorbances obtained in the two coloration systems.By using the developed UV-Vis method,the average contents of oleuropein in the olive leaves and purified extractums were 11.6% and 63.4% with RSDs（n=3）of 1.5% and 12%,respectively.Compared with the content determined by HPLC method,the relative error of this method was less than 4%.The result showed that this method could be used to replace the HPLC method for the determination of the content of oleuropein in the olive leaves or its products as the for mer was more simple,faster and lower cost than the latter.It can be looked as a reference methodfor the indirect determination of the active components in herbal materials or natural products. |