Accurate determination of molar mass distribution for disperse cellulose samples has proved to be a challenging task. While size-exclusion chromatography coupled to multi-angle light scattering (MALS) and differential refractive index (DRI) detectors has become the most commonly used method for molar mass determination of celluloses, this technique suffers low sensitivity at the low-molar mass range. As discussed here, the universal method for accurate molar mass distribution analysis of cellulose samples not exists and thus thorough understanding on the differences of the various methodological approaches is important. In this study, the focus is in the accurate determination of the low-molar mass fraction. The results obtained by combining the two calibration strategies, MALS/DRI for polymeric region of a cellulose sample and conventional calibration for oligomeric region, was compared to the results obtained using only MALS/DRI (with extrapolation of the curve where signal-to-noise of MALS is low). For birch pulp sample, the results from the two approaches were comparable; it should be highlighted, however, that MALS/DRI slightly overestimates the molar masses at the low-molar-mass region.

事实证明，准确测定分散纤维素样品的摩尔质量分布是一项艰巨的任务。虽然与多角度光散射（MALS）和示差折光指数（DRI）检测器结合的尺寸排阻色谱法已成为确定纤维素摩尔质量的最常用方法，但该技术在低摩尔质量范围内灵敏度较低。如此处讨论的那样，不存在用于纤维素样品的精确摩尔质量分布分析的通用方法，因此全面了解各种方法学方法的差异非常重要。在这项研究中，重点是准确确定低摩尔质量分数。通过结合两种校准策略获得的结果，将纤维素样品的聚合物区域的MALS / DRI和低聚物区域的常规校准与仅使用MALS / DRI的结果进行了比较（对MALS的信噪比很低的曲线进行了推断）。对于桦木纸浆样品，两种方法的结果是可比较的。然而，应该强调的是，MALS / DRI稍微高估了低摩尔质量区域的摩尔质量。