Analytical methods for determining functional groups in various technical lignins
Analytical methods for determining functional groups in various technical lignins
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DOI：
10.1016/j.indcrop.2007.02.006
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发表时间：
2007-08-01
影响因子：
5.9
通讯作者：
Salvado, Joan
中科院分区：
文献类型：
--
作者：
El Mansouri, Nour-Eddine;Salvado, Joan
本文比较了硫酸盐法、亚硫酸盐法、碱/蒽醌法、有机溶剂法和乙醇法木质素中官能团的测定方法。这些木质素根据甲氧基、酚基和脂肪羟基、羰基、羧基和磺酸基进行了表征。所用的分析方法有：气相色谱法、氨解法、紫外光谱法、H-1和（13）CNMR光谱法、肟化法、IFTIR光谱法、酸数测定法、非水电位法和水电位法。对各种羟基（酚类和脂肪族）分析方法的统计比较表明，所得结果不具有完全的可比性。胺解法和非水电位法被认为是最可靠的酚羟基测定方法。我们观察到羰基的测定方法也有相同的趋势，并选择近似法作为测定总羰基的可靠方法。羧基处理方法的结果在0.05的显著水平上具有相关性。我们选择了水滴定法和非水滴定法作为可靠的木质素测定方法。我们还比较了所有的商业木质素在官能团方面。最后，通过对各种工艺木质素的官能团进行完整表征，建立了所研究的每种木质素最完整、最具代表性的展开式C-9。(C) 2007 Elsevier B.V.版权所有
In this paper we compare various analytical methods for determining functional groups in technical lignins of five different origins: kraft, sulfite, soda/anthraquinone, organosolv and ethanol process lignins. These lignins were characterized in terms of methoxyl, phenolic and aliphatic hydroxyl, carbonyl, carboxyl and sulfonate groups. The analytical methods used were: gas chromatography, aminolysis, UV-spectroscopy, H-1 and(13) CNMR spectroscopy, the oximating method, IFTIR spectroscopy, acid number determination, and non-aqueous and aqueous potentiometry.The statistical comparison of the various analytical methods for hydroxyl groups (phenolic and aliphatic) shows that the results obtained are not fully comparable. Aminolysis and non-aqueous potentiometry are assumed to be the most reliable for phenolic hydroxyl. We observed the same trend for the methods for carbonyl groups and selected the oximating method as reliable for determining total carbonyl. The results for the methods used for carboxylic groups showed correspondence at a significance level of 0.05. We selected aqueous and non-aqueous titration as being reliable for the lignins studied. We also compare all the commercial lignins in terms of functional groups.Finally, by completely characterizing the functional groups of various technical lignins, we have established the most complete representative expanded formula C-9 for each lignin under study. (C) 2007 Elsevier B.V. All rights reserved.