样品的重均分子量(Mw)和分子量分布(Mw/Mn)由凝胶渗透色谱 (gel permeation chromatography, GPC) 测定。TSP P100 高效液相色谱仪 (美国，Thermoquest公司生产) 配以TSK G3000-PWXL色谱柱。流动相为0.2mol/L CH3COOH /0.1mol/L CH3COONa溶液，流速1.0ml/min，柱温保持30°C，RI150示差折射检测器检测。测试样品浓度为0.4% (w/v)，以TOSOH pullulan 为分子量标准，用江申工作站(大连江申色谱软件公司生产) 进行数据处理得到重均分子量Mw和分子量分布Mw/Mn。
Determiantion of molecular weight
Weight-average molecular weight (Mw), number average molecular weight (Mn) and molecular weight dispersion (Mw/Mn) of sample were measured by gel permeation chromatography (GPC). The GPC equipment consisted of TSK G3000-PWXL columns, TSP P100 pump and RI 150 refractive index detector. The eluent was 0.2 M CH3COOH/0.1 M CH3COONa. The flow rate and column’s temperature was maintained at 1.0 ml/min. The column temperature was maintained at 30°C. The sample concentration was 0.4 mg/ml. The standards used to calibrate the column were TOSOH pullulan. All data provided by the GPC system were collected and analysed using the Jiangshen Workstation software package.
Figure 1. GPC profiles of Low Molecular Weight Chitosan