秸秆降解产物的仪器分析(二)——用气液色谱法测定稻草结构性多糖水解产物的化学成分

Instrumental Analysis of Degradation of Crop Straws (Ⅲ):Determination of Monosaccharide Composition of Rice Straw Structural Polysaccharides by GLC

用气液色谱法对3种典型预处理(NaOH 处理、尿素处理和未处理)秸秆经不同前处理程序(乙醇(体积分数=80%)超声波浸提、中性洗涤、酸性洗涤和对照)后被硫酸水解的产物进行了分析和比较。结果表明,用乙醇(=80%)超声波浸提能有效地保持秸秆细胞壁结构性多糖的完整特征。此外,首次找到了在糖腈乙酰酯法制备单糖衍生物过程中控制葡萄糖和半乳糖不出杂峰(异构衍生物)的条件。针对影响肟化和乙酰化过程中的各种因素和条件进行了优化,并给出了一套快速、完整、适用的日常分析方法。

The monosaccharide composition of rice straw structural polysaccharides obtained from acid hydrolysis through 3 typical preparations(80% ethanol extracts of fibre,NDF,ADF and the control)is quantitatively analyzed by GLC.The results show that the recovery of the structural polysaccharides is obtained by ultrasonic treatment with 80% aqueous ethanol.The formation of the by-products occurring with the aldononitrile acetates of glucose and galactose can be overcome by increas- ing the ratio of hydroxylamine hydrochloride to water in the solution before oxima- tion and acetylation.The factors influencing the yield of derivation of monosaccha- ride to aldononitrile acetates is investigated,and the analytical procedures described here allow the monosaccharide composition of plant cell wall preparations to be determined simply,rapidly,and on a routine basis.