水溶性超高效聚合物色谱法测定木质素磺酸盐分级分离产物的相对分子质量分布

以木质素磺酸盐及其超滤分级分离产物为研究对象，系统考察了流动相pH值、离子强度等测试条件对超高效聚合物色谱（APC）法分析水溶性天然高分子相对分子质量的影响，并重点探讨了影响分析结果的非体积排阻效应。以pH6.8的0.1 mol/L NaNO₃水溶液为流动相，采用3根Waters水溶性色谱柱串联，进样量为10 μ L，流速为0.5 mL/min，木质素磺酸盐在色谱柱中获得了精细分离，其相对分子质量分布在8个相对分子质量区间。采用优化获得的测试条件表征木质素磺酸盐的超滤分级分离产物，测试结果表明，超滤法分离的3个组分实现了很好的色谱分离，对应的数均相对分子质量（M_n）分别为40410、12208和1516 Da，证明超滤法对木质素磺酸盐实现了高效分离。该方法为木质素磺酸盐分级分离产物的进一步应用提供了测试基础。

Determination of the relative molecular mass distribution of the ultrafiltration fractionation product of lignosulfonate by advanced polymer chromatography

The effects of testing conditions, such as pH and ionic strength of the mobile phase, on the relative molecular mass obtained by advanced polymer chromatography (APC) were investigated systematically. The non-size exclusion effects were discussed for lignosulfonate and its ultrafiltration fractionation product. The relative molecular mass distribution of lignosulfo-nate was well-characterized by an APC system using three columns in series, with a 10 μ L injection volume and 0.1 mol/L NaNO₃ as the aqueous mobile phase, at a flow rate of 0.5 mL/min. The relative molecular mass distribution is in the eight molecular mass ranges. Optimized test conditions were used to characterize the ultrafiltration fractionation product of lignosulfonate. The obtained number average relative molecular masses (M_n) of the three components were 40410, 12208, and 1516 Da, indicating that lignosulfonate was well separated into three fractions by ultrafiltration membrane separation. The APC technique presented herein provides the basis for further application of the fractional separation products of lignosulfonate.