SEDIMENTATION FIELD-FLOW FRACTIONATION AT GRAVITATIONAL-FIELD OF RED-BLOOD-CELLS - SYSTEMATIC STUDIES OF INJECTION CONDITIONS

Field Flow Fractionation (FFF), which uses the gravitational field for retention, elution, and separation of cellular materials, appeared to obtain a constant success. Blood cells, as well as parasites, were se parated and isolated using this very simple method. A need emerged, th erefore, to evaluate its separation performance. Towards that objectiv e, and because of numerous common features of FFF with chromatography, the injection conditions appeared to be critical. Therefore, we have analysed the effect of injected concentration, of injected volume, and of the specific injection procedure widely used in FFF the ''stop fla w time relaxation process.'' In the light of numerous reports, red blo od cells (RBC) appeared to be considered as a ''model'' for cell analy sis in FFF, and were eluted according to a mechanism described as ''St eric Hyperlayer,'' retention properties of RBC were therefore analysed versus carrier flow rate intensities. Guidelines are given to elute R BC in gravitational FFF depending on the separation objectives i.e., a nalytical or semi preparative.