一种不经分离定量测定木质纤维中木质素含量的方法

本发明公开了一种定量测定木质纤维中木质素含量的方法∶将一系列不同木质素含量的木质纤维试样进行粉碎、脱提取物；将得到的试样球磨处理；称取得到的试样置于LiC1/DMSO溶剂体系中进行溶解；将溶解液稀释，控制稀释后溶液的紫外吸光度值在0.2～0.8∶建立紫外吸光度值与木质素浓度的标准曲线。测定待测试样溶液的紫外吸光度值，根据标准曲线计算木质素的含量。本发明首次提出了机械力作用联合LiC1/DMS0溶剂溶解，在不进行木质素提取和化学处理e 的条件下，用紫外比色的方法测定木质素含量，可适合于不同原料木质素含量的直接测定，与使用TAPPI法测定木质素结果接近，不改变木质素的结构、方法简便、准确度和灵敏度高。

This invention discloses a method for the quantitative determination of lignin content in lignocellulosic fibers. The specific operational steps are: firstly, crush a series of lignocellulosic fiber samples with different lignin contents and remove their extractives; secondly, perform ball milling treatment on the pretreated samples; thirdly, weigh an appropriate amount of the ball-milled samples and dissolve them in a LiCl/DMSO solvent system; fourthly, dilute the obtained solution to control the UV absorbance of the diluted solution within the range of 0.2 to 0.8, and establish a standard curve between UV absorbance and lignin concentration; finally, measure the UV absorbance of the test sample solution, and calculate the lignin content based on the established standard curve. For the first time, this invention proposes a strategy combining mechanical force treatment and LiCl/DMSO solvent dissolution to determine lignin content via UV colorimetry without conducting lignin extraction and chemical processing. This method can be directly used for the quantitative determination of lignin content in various raw materials, and the obtained results are consistent with those measured by the TAPPI method. Moreover, it does not alter the structure of lignin, with the advantages of simple operation, high accuracy and high sensitivity.