高效凝胶色谱法测定聚乙烯亚胺的分子量及其分布

Determination of Molecular Weight and Its Distribution of Polyethylenimine by High Performance Gel Chromatography

目的:探讨高效凝胶色谱法测定聚乙烯亚胺(PEI)及其衍生物的分子量及其分布。方法:采用Ultrahydrogel 250(300mm×7.8mm)色谱柱;以已知相对分子量的PEI为标样;醋酸-醋酸盐缓冲液(0.2mol/1醋酸-0.1mol/1醋酸钠)为流动相;柱温40℃;流速1ml/min;示差折光检测器。结果:测得自制PEI衍生物的重均分子量(M_w)为5093,数均分子量(M_n)为2090、Z均分子量(M_z)为11031,分布宽度(M_w/M_n)为2.44。结论:高效凝胶色谱法操作简单、灵敏度高,适合于快速、简便地测定PEI及其衍生聚合物的分子量及其分布。

Objective： To determine molecular weight and its distribution of PEI and its derivatives by high performance gel chromatography （HPGCG）. Methods： Molecular weight and its distribution of PEI and its derivatives were determined by HPGCG on Ultrahydrogel 250 （300mm× 7.8mm） column at 400C; PEI with known relative molecular weight was selected as standard sample; acetate-acetate buffer （0.2mol/1 acetate-0.1mol/1 sodium acetate ） as the mobile phase; It was detected by differential refractometry. The flow velocity of the mobile phase was l ml/min. Results： The weight-average molecular weight （Mw） of self-made PEI derivatives Was 5093; number-average molecular weight （Mn） 2090; Z-average molecular weight （Mz） 11031; distribution width （Mw/Mn）. Conclusions： HPGCG method is easy to operate, with high sensitivity, which is suitable for the molecular weight and its distribution determination of PEI and its derivatives.