Determination of 4 Nucleosides via One Reference Compound in Chinese Cordyceps by HPLC-UV at Equal Absorption Wavelength

A high-performance liquid chromatography (HPLC) method for the determination of 4 nucleosides by one reference compound in Chinese cordyceps was developed. The sample of Chinese cordyceps was prepared by ultrasonic extraction with a 0.5% phosphoric acid aqueous solution. The separation of the sample was performed on a CORTECS T3 column (100 mm × 4.6 mm, 2.7 μm) by gradient elution with acetonitrile and water at a flow rate of 1.0 mL/min. The wavelengths were set as 258 nm (0-5 min), 252 nm (5-9.1 min), 258 nm (9.1-10.5 min), 249 nm (10.5-20 min) at which 4 nucleosides exhibited identical ultraviolet absorption. The accuracy, precision, reproducibility, and stability tests of the HPLC method were carried out, and the results indicated that the established HPLC method was suitable for the quantitative analysis of 4 nucleosides in Chinese cordyceps. This approach was compared to the traditional external standard method with 4 nucleoside reference compounds and the relative standard errors of the content determination results by the 2 methods were less than 3.5%. The HPLC method developed for quantitative measurement of 4 nucleosides in Chinese cordyceps is simple, lower cost, and time-saving, which provides a methodology alternative for quality control of Chinese cordyceps.