魔芋葡甘聚糖分子量的GPC-LS-RI与LS法研究比较

运用静态激光光散射仪,比较了凝胶渗透色谱-激光光散射联机(GPC-LS-RI)法与(LS)单机法研究魔芋葡甘聚糖(KGM)的重均分子量(-Mw)。实验结果显示,联机法测得KGM的-Mw=2.476×105g/mol,单机法测得KGM的-Mw=2.508×105g/mol,二者差比仅为1.3%,表明两种方法测定KGM重均分子量的实验数值十分接近;同时联机法分析了KGM的多分散系数(-Mw/-Mn)及构象指数(β),而单机法求得了联机法无法测得的KGM分子与溶剂分子之间相互作用的第二维利系数(A2)。这些均为KGM分子形态的理论研究提供了参考依据。

GPC-LS-RI and LS Comparison of the Molecular Weight of Konjac Glucomannan

The gel permeation chromatography combined with laser light scattering and refractive index(GPC-LS-RI) online method and(LS) single method researched the molecular weight(M-w) of konjac glucomannan(KGM) were used by static laser light scattering instrument in this paper.The results show that the determination results of molecular weight of KGM are similar by two method,the molecular weight of KGM is 2.476×105 g/mol by on-line method measured,and it is 2.508×105 g/mol by single method measured,compared with only 1.3% difference between the two method.And at the same time,the molecular weight distributions of KGM and conformation index were analyzed by online method.While the second Virial coefficient(A2) that characterizes the interaction between KGM molecules and solvent molecules was acquired by single method,which can provide reliable foundation for the molecular chain morphology research of KGM.