The valorization of biorefinery downstream lignin fractions is a key issue in increasing the sustainability of second-generation biofuels. The development of reliable methodologies for the selective determination of the apparent masses of the poly(hydroxy)-aromatic ethers arising from lignin depolymerization reaction is crucial. Diffusion-ordered spectroscopy (DOSY) has been tested to estimate the molecular weight in downstream biorefinery lignins and base-catalyzed depolymerization reaction mixtures. Excellent correlation was found in the calibration of molecular weight and diffusion coefficients with standards. DOSY permitted the selective estimation of the apparent masses of different fractions in the lignin and in the depolymerization reaction mixtures, providing a more profound knowledge of the reaction mixture composition than that obtained with traditional size-exclusion chromatography (SEC). Excellent correlations have been achieved in the estimation of the apparent masses of poly(hydroxy)-aromatic ethers between SEC and DOSY. This permits a reliable estimation of the molecular weight of different fractions in the lignin and in the depolymerization product, which is essential for their further applications.

中文翻译：

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用于基础催化解聚反应混合物产生的真实木质素和馏分中分子量选择性测定的系统扩散有序光谱法

生物炼油厂下游木质素馏分的增值是提高第二代生物燃料可持续性的关键问题。开发用于选择性测定木质素解聚反应产生的聚（羟基）-芳族醚表观质量的可靠方法至关重要。已经测试了扩散有序光谱法（DOSY）来估算下游生物炼厂木质素和碱催化的解聚反应混合物中的分子量。在分子量和扩散系数与标准品的校准中发现极好的相关性。DOSY允许选择性估计木质素和解聚反应混合物中不同馏分的表观质量，与传统的排阻色谱法（SEC）相比，它提供了对反应混合物组成更深入的了解。在估算SEC和DOSY之间的聚（羟基）-芳族醚的表观质量时，已经获得了极好的相关性。这允许可靠地估计木质素和解聚产物中不同部分的分子量，这对于它们的进一步应用是必不可少的。