混合溶剂作淋洗剂的体积排除色谱(SEC)中溶剂化高分子峰和溶剂峰的关系

Relationship Between Solvated Polymer Peak and Solvent Peak Using Mixed Solvent as Eluents in Size-exclusion Chromatography

以混合溶剂作淋洗剂的体积排除色谱(SEC)中高分子样品一般会出现2个峰,分别是溶剂化高分子峰和自由溶剂峰.理论分析结果表明,溶剂化高分子峰面积(A3eff)是"裸高分子"峰面积(A3)和被束缚溶剂峰面积(A1*)的加和,被束缚溶剂峰面积(A1*)和自由溶剂峰面积(A*2)大小相等符号相反.以聚苯乙烯(3)-氯仿(1)-甲醇(2)体系为研究对象,分别对A3eff,A3及A2*进行了实验测定,证实了理论推断的正确性,表明由高分子峰和由溶剂峰来求算优先吸附系数是等价的.

In Size-exclusion Chromatography （SEC） two peaks are often observed for polymer samples when solvent mixtures are employed as eluents. These two peaks are solvated polymer peak and free solvent peak respectively. Theoretical analysis shows that the peak area of the solvated polymer A3^eff is actually the sum of the ＂naked polymer＂ peak area A3 and the bound solvent peak area A1^＊. A1^＊ is equal to that of the free solvent peak A2^＊ in magnitude but opposite in sign. In this study the data of A3^eff, A3 and A2^＊ were measured for the system of polystyrene （3） -chloroform （ 1 ） -methanol （2）. The results support the analytical prediction and indicate that the preferential adsorption coefficient can be determined from either the polymer peak or the free solvent peak.