Viebke C, Williams PA
Centre for Water Soluble Polymers, The North East Wales Institute, Plas Coch, Wrexham, UK.
Anal Chem. 2000 Aug 15;72(16):3896-901. doi: 10.1021/ac991205x.
Asymmetrical flow field-flow fractionation coupled to multiangle laser light scattering has been shown to be an effective method to determine the molar mass distribution of polysaccharides. Two polymer standards, dextran and pullulan, were analyzed in the temperature range 30-60 degrees at intervals of 10 degrees C. The weight average molar mass and molar mass distribution obtained at each temperature agreed well with quoted values. The diffusion coefficient, hydrodynamic radius, radius of gyration, and activation energy of diffusion were calculated and all agreed well with literature data obtained by dynamic and static light scattering. The asymmetry factor Rg/Rh suggests a flexible random coil conformation for both polymers, which was supported by the molar mass dependence of both the radius of gyration and the hydrodynamic radius. The results show the potential of asymmetric flow field fractionation coupled to multiangle laser light scattering in undertaking measurements of molar mass distribution as a function of temperature.
非对称流场-流分级联用多角度激光光散射已被证明是一种测定多糖摩尔质量分布的有效方法。在30至60摄氏度范围内，以10摄氏度为间隔对两种聚合物标准品葡聚糖和支链淀粉进行了分析。在每个温度下获得的重均摩尔质量和摩尔质量分布与引用值吻合良好。计算了扩散系数、流体动力学半径、回转半径和扩散活化能，所有这些都与通过动态和静态光散射获得的文献数据吻合良好。不对称因子Rg/Rh表明两种聚合物均具有柔性无规线团构象，这一点得到了回转半径和流体动力学半径对摩尔质量的依赖性的支持。结果表明，非对称流场分级联用多角度激光光散射在进行作为温度函数的摩尔质量分布测量方面具有潜力。
