Submicron particle size and polymerization excess surfactant analysis by capillary hydrodynamic fractionation (CHDF)

The particle size distribution of a blend of two polymer latex monodisperse standards, 86 and 238 nm, has been measured by capillary hydrodynamic fractionation (CHDF). The particle size distributions obtained agreed well with the expected particle diameters. The relative amounts of the two standards in the blends were accurately measured at different blend ratios. The particle size distribution of a parenteral lipid sample was successfully measured. A soluble species was fractionated from latex standards smaller than 100nm. This soluble species appears to be excess surfactant used in the preparation of small size monodisperse latexes. The amount of excess surfactant increases as the particle diameter of the standard decreases.