Abstract Different types of lignin have been depolymerized via oxidative cleavage in sub- and supercritical water. As expected, a wide range of products of different structure and molecular weight have been obtained. Instead of analysing them one by one, we believe that it is equally useful and much more feasible to determine certain global parameters such as type of aromatic substituents, OH functionality or molecular weight distribution, particularly if the objective is to obtain a mixture of compounds with a particular application. To this end, each sample (products of lignin depolymerisation) was fractionated according to its solubility in water and ethyl acetate and the yield of the different fractions was determined. Then each fraction was analysed using CHNS elemental analysis; 31P- and 13C NMR and aqueous Gel Permeation Chromatography (GPC). Important conclusions about the effect of the reaction on the lignin structure can be deduced. These conclusions agree with previous observations found in literature. Based on these conclusions, some further insights have been proposed.

中文翻译：

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高温水中木质素解聚产物的定量分析

摘要 在亚临界和超临界水中通过氧化裂解可以解聚不同类型的木质素。正如预期的那样，已经获得了范围广泛的不同结构和分子量的产品。我们认为，与其一一分析它们，不如确定某些全局参数（例如芳族取代基的类型、OH 官能度或分子量分布）同样有用且更可行，特别是如果目标是获得具有以下特征的化合物的混合物一个特定的应用程序。为此，根据其在水和乙酸乙酯中的溶解度对每个样品（木质素解聚的产物）进行分级，并确定不同级分的产率。然后使用 CHNS 元素分析对每个馏分进行分析；31P-和13C NMR和水性凝胶渗透色谱(GPC)。可以推导出关于反应对木质素结构影响的重要结论。这些结论与先前在文献中发现的观察结果一致。基于这些结论，提出了一些进一步的见解。