Chromatographic hydrodynamic chromatography

S.S. Huang, Size exclusion/hydrodynamic chromatography, in Handbook of Size Exclusion Chmma-tography and Related Techniques, vol. 91 (Chromatographic Sciences Series), C.-S. Wu, ed., Marcel Dekker, Inc., New York, 2004, p. 481. 

Hydrodynamic chromatography (HDC) offers a means of obtaining size information on colloidal particles in suspension with the same ease that is characteristic of chromatographic methods for size analysis of molecules in solution. 

Hydrodynamic chromatography is a chromatographic technique for measuring the particle-size distributions of polymer lattices of approximately 0.1-1 pm and inorganic colloids in the 0.01-40 pm range. 

Size exclusion chromatography (SEC) separates molecules of a polymer sample on the basis of hydrodynamic volume. When the chromatograph is equipped only with a concentration-sensitive detector, i.e. conventional SEC, a molecular weight distribution (MWD) can be obtained from the chromatogram only through use of a calibration function relating molecular weight and elution volume V (2). 

Such precise control of porous properties is expected to be very useful in the design of specialized CEC columns for separation in modes other than reversed-phase. For example, size exclusion chromatography (SEC) is an isocratic separation method that relies on differences in the hydrodynamic volumes of the analytes. Because all solute-stationary phase interactions must be avoided in SEC, solvents such as pure tetrahydrofuran are often used as the mobile phase for the analysis of synthetic polymers, since they dissolve a wide range of structures and minimize interactions with the chromatographic medium. Despite the reported use of entirely non-aqueous eluents in both electrophoresis and CEC [65], no appreciable flow through the methacrylate-based monoliths was observed using pure tetrahydrofuran as the mobile phase. However, a mixture of 2% water and tetrahydrofuran was found to substan-... 

By the use of different modes of liquid chromatography it is possible to separate polymers selectively with respect to hydrodynamic volume (molar mass), chemical composition or functionality. Using these techniques and combining them with each other or with a selective detector, two-dimensional information on different aspects of molecular heterogeneity can be obtained. If, for example, two different chromatographic techniques are combined in a cross-fractionation mode, information on CCD and MMD can be obtained. Literally, the term chromatographic cross-fractionation refers to any combination of chromato-... 

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