Size classification method of packing materials for aqueous gel chromatography

Instrumentation of classification system and application to dextran particles

Abstract

The size classification of low density particles e.g. dextran or agarose (d_p=1.001.05) is relatively difficult compared to that of ion exchange resin (d_p= 1.2). In this paper, the concept of hydrodynamic chromatography is introduced for the size classification of low density particles. Aqueous solution containing 10% 2-propanol was used to inhibit aggregation of particles. The classification was made for the suspension using the long range of laminar flow. Elution time (t_f) of particles can be predicted using the following equation:
t_f =ηl /[v_cη - 1.960×10^-3(d_p - d_f) a²]
t_f : elution time (h), η : viscosity of eluent (g/cm s), l : length of laminar flow layer (cm), v_c : counter flow rate (cm/h), d_p: density of particle (g/cm³), d_f: density of eluent (g/cm³), a: diameter of particle (μm). Sephadex G-200 was classified using this method by the following conditions: column size; 155×5.5 cm I.D., counter flow rate; 4.4 cm/h, eluent; 10 % 2-propanol. For the given size of classified particles, the elution time was found to be approximately identical with that predicted by the equation. Particles of 10 and 20 μm were flowed out within 48 h (the predicted time is 34.6 h) and 96 h (the predicted time is 71.6 h) respectively.