Size-exclusion chromatography
A clear disadvantage to SEC is with short retention times the peaks overlap and little information could be extracted from such data. Resolution (how well two peaks can two peaks be distinguished between) must be sacrificed if the process is to be shorter in time. SEC does not provide data to distinguish between components of similar molecular mass. For example if component A has molecular mass equal to 900 g/mol and component B has molecular mass equal to 950 g/mol, SEC will show one peak in this region and both components will be represented by the same peak.  To have statistically different peaks there should be a 10% difference between molecular weight. Also lumped into this category are enantiomers and diastereomers which are molecules of the same molecular weight but have slightly different structures. Last SEC fails to take into account for a component’s viscosity or resistance to flow.