GB/T 21863-2008 in English

《GB/T 21863-2008凝胶渗透色谱法（GPC） 用四氢呋喃做淋洗液》由TC251（全国危险化学品管理标准化技术委员会）归口，主管部门为国家标准化管理委员会。
本标准为首次发布。本标准规定了凝胶渗透色谱法（ＧＰＣ）测定在四氢呋喃（ＴＨＦ）中溶解的聚合物的分子量分布、数均分子量Mn和重均分子量Mw的方法和试验条件。本标准等同采用德国标准化组织ＤＩＮ５５６７２-１：２００７ 《凝胶渗透色谱法（ＧＰＣ）　第１部分：用四氢呋喃（ＴＨＦ）作洗脱溶剂》（德文版）。

Scope

This standard specifies the methods and tests for gel permeation chromatography (GPC) to determine the molecular weight distribution, number average molecular weight M_n and weight average molecular weight M_w of polymers dissolved in tetrahydrofuran (THF). condition. Even if individual polymers are chromatographically separated with good reproducibility, this method is not suitable if specific interactions (e.g. absorption) occur in the sample/eluent/separating material system. Gel Permeation Chromatography (GPC) is a relative method requiring calibration with commercially available linear polystyrene standards of known molecular weight using an absolute method. The results for polymer samples with different structures can only be used as reference values for groups of samples of the same structure. This standard is not applicable to the determination of polymers with M_n greater than 10⁶g/mol (see Appendix C). Correction methods (such as eliminating peak spread) cannot be implemented in this standard. If absolute molar masses are to be determined, absolute methods should be used (eg membrane osmometry for M_n, or light scattering for M_w).