利用酸水解法把乳中的唾液酸释放出来，以邻苯二氨盐酸盐（10 mg/mL）为衍生化试剂，在80 ℃水浴锅中衍生40 min，采用Symmetry C18柱（250 mm×4.6 mm，5 m）；流动相为1.0%的四氢呋喃水溶液（含0.2%磷酸）-乙腈（92:8）；流速为1.0 mL/min，柱温为35 ℃；紫外检测波长230 nm。结果表明，唾液酸在10~320 μg/mL范围内线性良好，平均回收率为95.7%。本方法具有灵敏度高，重复性好等特点，可准确测定乳中唾液酸含量。

Sialic acid in milk was released via acid hydrolysis, and then derivated with O-pheny-lenediamine •2HCl (10 mg/mL) at 80 ℃ for 40 min. The content of the derivated sialic acid was determinded on a Symmetry C18 column (250 mm×4.6 mm, 5 μm) using a UV detector at 230 nm. The mobile phase was a mixture of 1.0% tetraphdrofuran (containing 0.2% phosphoric acid) and acetonitrile (92:8) at a flow rate of 1.0 ml/min. The column temperatue was 35 ℃. The results indicated the linear rang of Sialic acid was 10~320 μg/mL and the average recovery was 95.7%. This method for the determination of the sialic acid content in milk had good reproducibility and high sensitivity.

河南省重点科技攻关项目（0522010800）