Strategy to improve the characterization of chitosan by size exclusion chromatography coupled with multi angle laser light scattering
Strategy to improve the characterization of chitosan by size exclusion chromatography coupled with multi angle laser light scattering
复制标题
尺寸排阻色谱结合多角度激光散射改善壳聚糖表征的策略
DOI：
10.1016/j.carbpol.2018.08.125
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发表时间：
2018-12-15
影响因子：
11.2
通讯作者：
Liu, Yonggang
中科院分区：
文献类型：
--
作者：
Kang, Yu;Wu, Xiaoxue;Liu, Yonggang
本文对重均摩尔质量M-w在33~427公斤/摩尔之间的壳聚糖样品进行了SEC-MALLS研究。由于与中性聚合物相比，阳离子壳聚糖在稀酸缓冲液中的卷曲构象延长，因此必须使用0.1-0.2 mg/mL的低进样浓度来避免SEC柱的过载。此外，对于高摩尔质量的壳聚糖样品，必须以不超过0.5毫升/分钟的洗脱液流速进行SEC。当流速为1.0和1.5mL/min时，最大壳聚糖物种的洗脱被推迟，导致摩尔质量分布向低摩尔质量区域扭曲。这种异常行为是由于层析模式从SEC转变为SLALOM层析，源于壳聚糖链在穿过填充柱的拉长流动中的卷曲-拉伸转变。
Here we present SEC-MALLS study for chitosan samples with weight average molar mass M-w between 33 and 427 kg/mol on columns packed with 8 mu m porous particles. A low injection concentration on the order of 0.1-0.2 mg/mL must be used to avoid overloading of the SEC columns, due to the extended coil conformation of cationic chitosan in the dilute acid buffer as compared to neutral polymers. Additionally, SEC must be performed at an eluent flow rate no more than 0.5 mL/min for high molar mass chitosan samples. At flow rates of 1.0 and 1.5 mL/min, the elution of the largest chitosan species is delayed, which leads to a distortion of the molar mass distribution towards lower molar mass region. Such an abnormal behavior is due to a chromatographic mode transition from SEC to slalom chromatography, originated from the coil-stretch transition of chitosan chains in elongational flow through the packed columns.