Measurement of pore diffusivity in separation media for high performance liquid chromatography.

It was demonstrated that the peak parking-moment analysis (PP-MA) method could be used as an alternative for the measurement of pore diffusivity (D(p)) in porous packing materials for HPLC. The value of D(p) of uracil was measured by the PP-MA method under non-retained conditions in the RPLC systems using C18-silica gel particles and C18-silica monolith as the stationary phase and 70 vol% methanol as the mobile phase. The value of D(p) was compared with that derived by the pulse response-moment analysis (PR-MA) method under the same conditions. The D(p) values of uracil derived by the PP-MA and PR-MA methods were almost in agreement with each other. Because the PP-MA and PR-MA methods have complementary characteristics as experimental methods for studying mass transfer kinetics, it is expected that the combination of the two methods would lead to an effective strategy for the measurement of D(p) in porous separation media for HPLC.