Tips and Tricks: GPC/SEC Copolymer Analysis in GPC/SEC 3: Two-dimensional Chromatography
Copolymer analysis is challenging due to the effect that at least two distributions can be present simultaneously: the molar mass distribution (MMD) and the chemical composition distribution (CCD). A problem in GPC/SEC, that cannot be solved by using any detection technique, is that the method may suffer from limited chromatographic resolution.
Combination of different separation techniques into a single experiment (multi-dimensional chromatography; also called 2D chromatography, orthogonal chromatography and cross-fractionation) can help to overcome this. The corresponding peak capacity in an n-dimensional separation is substantially higher because each dimension contributes to the total peak capacity as a factor and not as an additive term.