Field- and flow-dependent trapping of red blood cells on polycarbonate accumulation wall in sedimentation field-flow fractionation

Sedimentation field-flow fractionation (SdFFF) instrumentation is now mature. Methodological procedure and particle separation development rules are well established even in the case of biological species. However, in some biological applications, retention properties of samples not predicted by any field-flow fractionation (FFF) elution models are observed. It is demonstrated that the trapping of cellular material in the separation system is not related to geometrical instrumentation features but to channel wall characteristics. The physicochemical particle-wall attractive interactions are different depending on the how-rate and field intensity applied. Separation power in SdFFF for biological species is therefore limited by the intensity of these interactions. In terms of separation, a balance is to be found between external field and flow intensity to limit particle-wall interactions. (C) 1999 Published by Elsevier Science B.V. All rights reserved.