Stability of perfluorocarbon blood substitutes determined by sedimentation field-flow fractionation.

It is shown that the method known as sedimentation field-flow fractionation, which has been applied to the separation and characterization of many industrial and biological particles and recently to emulsions, can be used to obtain high-resolution droplet diameter profiles for perfluorocarbon blood substitutes. Following a description of the methodology, experiments are described for two commercial perfluorocarbon emulsions, Fluosol-DA 20% and Fluosol-43. The droplet diameter profiles for both of these blood substitutes are shown to shift to noticeably higher diameter values in less than 2 months. The diameter at the profile peak for Fluosol-DA 20%, for example, shifts from 0.19 to 0.27 micron in 56 days.