Overcoming Fear, Uncertainty, and Doubt in GPC: The Need for an Absolute Measurement of Molar Mass
While conventional calibration for gel permeation (GPC) or size-exclusion chromatography (SEC) is useful, there are inherent disadvantages in this type of analysis that introduce experimental error. This uncertainty may cast serious aspersions on the rigour and utility of the results. Multi-angle light scattering (MALS) detection is quite simple to add to an existing chromatography system and can help overcome the challenges faced with single detector chromatography and conventional calibration-based methods. An alternative separation technique called asymmetric flow field-flow fractionation (AF4) offers tunable, column-free fractionation.