Kinetic performance comparison of a capillary monolithic and a fused-core column in micro-scale liquid chromatography

The kinetic performance of monolithic and fused-core capillary C18 columns was compared in isocratic-elution liquid chromatography. Heptanophenone was chosen as a test compound. The (u0, H) couple obtained in a column with permeability Kv0 was transferred into a plate number, dead time (N, t0) couple and the kinetic plots were achieved by using a Kinetic Method Plot Analyzer template. The u0,opt (0.98 mm/s for the monolith and 1.05 mm/s for the fused-core column) and Hmin (17.58 μm for the monolith and 18.08 μm for the fused-core column) values determined from the van Deemter curve were found to be almost identical, whereas the Nopt (the plate number for which the support achieves its best analysis time/pressure cost ratio) (150,000 for monolith and 41,000 for fused-core column), maximal plate number, Nmax (the maximum plate number that can ever be reached with a support) (550,000 for monolith and 120,000 for the fused-core column) and optimal analysis time, topt (the time needed to obtain Nopt plates) (18,583 s for the monolith and 4,068 s for the fused-core column) performance numbers determined from the kinetic plots were found to be significantly different.

► Isocratic performance of packed capillary LC columns was compared.
► The u0,opt and Hmin were found to be almost identical between the two column types.
► Nopt, Nmax and topt were significantly different between the two column types.