Abstract: A high performance liquid chromatography (HPLC)-based method was developed for the determination of N-acetylneuraminic acid added to raw materials and dairy products. After pre-treatment of the test samples,a C₁₈ column (250 mm×4.6 mm,5 μm) was used,and 0.005 mol/L sulfuric acid solution and 0.005 mol/L methanol sulfuric acid solution were used as mobile phases in the gradient elution method. The experimental conditions were optimized by one-way and orthogonal experiments,and the retention time of N-acetylneuraminic acid was 5.69 min when the column temperature was 40 ℃,the flow rate was 0.6 mL/min,the pH value of the mobile phase was 2.0,and the ratio of the mobile phase was 85∶15 (V/V),which showed good separation and precision,and a good linearity in the concentration range of 0~3.0 mg/mL (R²= 0.9989). The spiked recoveries ranged from 99.2%~103.4%,and the precision tests（relative standard deviation（RSD）ranged from 0.47% to 1.26%. The method is easy to operate,with accurate and reliable results and good precision,which not only improves the technical operation of the inspectors,but also applies to the analysis of N-acetylneuraminic acid content in raw materials and dairy products.

Key words: Sialic acid, High performance liquid chromatography, Dairy products, Detection method