新型壳寡酸标准物质的膜法分离制备

Study on separation and preparation of certified reference material of chitin oligosaccharide acid by membrane

基于不同类型膜的分离机理,构建了壳寡酸-无机盐混合体系的分离技术路线：首先用超滤膜除去壳寡酸混合体系中大部分无机盐和不具备生物活性的小分子壳寡酸;进一步用纳滤膜和透析膜除盐,制备分子量为1000~3500的壳寡酸产品。壳寡酸原始样品中无机盐成分与含量用离子色谱定量检测,结果显示,样品所含的无机盐阴离子为SO4^2-、PO4^3-和NO3^-,其在单位质量样品中的含量分别为171.9、297.04和129mg/g。采用电导率仪检测壳寡酸混合溶液中无机阴离子的总含量,其精度经离子色谱验证,结果显示,当透过液电导率小于5μs/cm时,经透析分离制备的高纯壳寡酸标准品检测不到无机阴离子。首次分离出具有活性功能的壳寡酸标准品,为壳寡酸的工业生产提供了参照标准。

Membrane separation process suitable for the mixture of oligosaccharide acids and inorganic salts was proposed based on membrane separation mechanism. Ultrafiltration membrane was used to separate oligosaccharide acids with different molecular weight distribution from the mixture of oligosaccharide acids and inorganic salts. The separated oligosaccharide acids solution was concentrated through nanofiltration, and further putrefied by dialysis membrane. Thus, the certified reference material of oligosaccharide acids with molecular weight of 1000~3500 was obtained. The composition and concentration of inorganic salts in the original mixture were detected by ion chromatography. The results showed that the contents of SO4^2- ,PO4^3- and NO3^- in lg oligosaccharide acids mixture were 171.9mg,297.04mg and 129mg respective- ly. Conductivity meter was used to detect total inorganic anions concentration, and the criterion of detection was proposed that the conductivity of permeate in dialysis should below 5μs/cm if inorganic anions could not be detected. The separated material with biological activity and high purity can be regarded as a kind of certified reference material of oligosaccharide acids.