sentences:  The more concentrated the eluent is, the more efficient the procedure would be.However, it is not always possible to concentrate the eluent, which can be considered as one more disadvantage.Absolute size-exclusion chromatography (ASEC) is a technique that couples a dynamic light scattering (DLS) instrument to a size exclusion chromatography system for absolute size measurements of proteins and macromolecules as they elute from the chromatography system.