Abstract:Objective To establish the method for determining the content of aspartic acid, tyrosine, and valine in cicada slough by pre- column derivatization reversed- phase high- performance liquid chromatography (HPLC). Methods Acid hydrolyzation was performed to prepare amino acid sample solution, and HPLC was performed after pre- column derivatization with phenyl isothiocyanate. HPLC was performed on a Kromasil C18 column (250 mm × 4.6 mm) with mobile phase A of 0.1 mol/L sodium acetate buffer solution- acetonitrile (93∶7) and mobile phase B of acetonitrile- water (4∶1) for gradient elution at a flow rate of 1.0 mL/min, a column temperature of 43 ℃, a wavelength of 254 nm, and a sample size of 20 μL. Results The amino acid derivative solution remained stable within 36 hours. The correlation coefficient between peak area and concentration for these three amino acids within the linear range was higher than 0.999 0, and the recovery rates (n=6) were 95.62%, 101.26%, and 100.00%, respectively. Conclusion The method established is stable and reliable and has good accuracy and reproducibility. It can be used for the determination of aspartic acid, tyrosine, and valine in cicada slough.