Chi Cong-Cong, Zhang Zeng, Chai Xin-Sheng, Ge Wei-Wei
State Key Laboratory of Pulp & Paper Engineering, South China University of Technology, Guangzhou 510640, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2010 Apr;30(4):1084-7.
The traditional Douglas colorimetric method (phloroglucinol - glacial acetic acid colorimetry) could only be used to measure all forms of five-carbon sugars, including mono-, oligo- and poly- saccharides. Relative improvement is done on this method to achieve simultaneous determination of pentosan, hexosan and their monosaccharides, by the dual-wavelength method. Results indicate that 425 nm is the equal molar absorption wavelength of pentose and hexose, while 553 nm is the maximum absorption wavelength of pentoses. So the calculating formula has been greatly simplified based on the absorbance at 425 and 553 nm. The research results of interfering substances in the extraction liquor show that the lignin and glucuronic acid has no significant influence on the determination of pentoses or hexoses. It is concluded that this improved method has high precision and accuracy, and its recovery range is from 97.4% to 101.9%. Therefore, as a simple and rapid method, it is quite appropriate for measuring mixed sugars of pentoses and hexoses in the extraction liquor from hardwood or gra minaceous plant.
传统的道格拉斯比色法（间苯三酚 - 冰醋酸比色法）仅能用于测定包括单糖、寡糖和多糖在内的所有形式的戊糖。在此方法基础上进行了相关改进，采用双波长法实现了对戊聚糖、己聚糖及其单糖的同时测定。结果表明，425 nm是戊糖和己糖的等摩尔吸收波长，而553 nm是戊糖的最大吸收波长。因此，基于425 nm和553 nm处的吸光度，计算公式得到了极大简化。对提取液中干扰物质的研究结果表明，木质素和葡萄糖醛酸对戊糖或己糖的测定没有显著影响。得出的结论是，这种改进后的方法具有较高的精密度和准确度，其回收率范围为97.4%至101.9%。因此，作为一种简单快速的方法，它非常适合用于测定阔叶木或禾本科植物提取液中的戊糖和己糖混合糖。
