Hydrodynamic chromatography of latex blends.

The ability to characterize the size and shape distributions of broadly polydisperse analytes is a driving force in particle size analysis. Multi-detector hydrodynamic chromatography (HDC), which has previously shown promise in its ability to characterize the size and shape of monodisperse, spherical polystyrene latex standards, is applied here to include the characterization of bi-, tri-, and tetramodal latex blends and their constituents varying in size, chemistry, and compactness. The ability of multi-detector HDC to distinguish between similar-sized particles of different chemistry is realized by the coupling of a concentration-sensitive detector and two different types of light scattering detectors. The use of both multi-angle static and quasi-elastic light scattering permits for determination of two different size parameters across the elution profiles of the blends. Combining the size information obtained from both light scattering methods provides a measure of how particle compactness changes as a function of size in a latex blend. Multi-detector HDC was shown to be a rapid and precise method for characterizing particle size, shape, and their distributions of broadly polydisperse analytes.