Abstract:Objective: To determine and compare the content of 18 amino acids from the Semen Platycladi Herbs of different origins. Method: Pre-column derivatization HPLC method was used for determination of amino acid content.The hydrochloric of Semen Platycladi Herbs with 6 mol·L-1 hydrochloric acid solution was at 110 ℃, 2, 4-dinitrofluorobenzene as the pre-column derivatization reagent.Elite-AAK amino acid analysis column (4.6 mm×250 mm, 5 μm) ;the mobile phase was acetonitrile-water (1:1)-buffer solution, the flow rate was set at 1.2 mL·min-1, gradient elution, detection wavelength was 360 nm, the column temperature was 27 ℃. Result: The linear correlation of 18 amino acids was larger than 0.999 1, each amino acids recoveries between 98.03%-103.21%, recoveries average of 100.36%, RSD≤1.77%. Conclusion: Pre-column derivatization HPLC method for determination of amino acids from the Semen Platycladi Herbs is feasible, which reveals the foundation of the relationship between quality and origin of the Semen Platycladi.