Abstract:

A fast, simple and accurate method for determination of lignin content in black liquor from straw pulp（BLSP）was proposed, based on an analysis for the typical absorption of 3,5-dinitrosalicylic acid(DNS) as well as black liquor in a fixed UV-visible wavelength region.The analysis indicated that, at wavelength 520 nm, a high linear relationship was found between the contents of lignin dissolved in BLSP and absorbance values of DNS.The interference of glucose and Na₂SO₃  in black liquor from straw pulp on measuring value could be eliminated.So, this method proposed can be used not only for the accurate determination of lignin content in BLSP but also for lignin content determination in BLSP that produced from basic Na₂SO₃ process.

摘要：

通过对3，5-二硝基水杨酸(DNS)及草浆黑液木素溶液紫外-可见特定波长区域光谱图的研究，建立了一种快速、简便、准确的草浆黑液中木素含量测定方法。研究结果表明，草浆黑液木素在520 nm处DNS溶液吸光度值与木素溶解量二者具有较高的线性关系。该方法在测量时可以排除草浆黑液中还原糖及亚硫酸钠的干扰。不但能测定碱法草浆黑液中木素含量，还可以测定碱性亚硫酸盐法草浆黑液中木素含量。采用该方法测定草浆黑液中木素相对含量是准确可靠的。