Comparison of Commercial Column Types in Liquid Chromatography

Abstract

Several commercially available liquid chromatographic column types have been experimentally evaluated. A conventionally-sized column containing 5 μm packing, a microbore column containing 10 μm packing, a column containing 3 μm packing, and two short, wide-bore columns containing 5 μm packing were compared at optimum velocity (van Deemter minimum) and at twice the optimum velocity where possible. All columns contained reversed-phase media of the C-18 type. Attention was focused on establishing advantages and limitations of each column with regard to maximum available plate count, minimum separation time, and required pressure drop. A van Deemter plot was constructed for each column type and the number of plates generated per unit length, time, and pressure was determined. In addition reduced parameters, separation impedance, peak capacities, and analysis times at a given k' were calculated. Calculations indicated the highest possible plate counts should be obtained with coupled microbore columns. Small particle (3 μm) columns provided the best performance for high speed, moderate plate count separations. Conventional-sized columns containing 5 μm packing material appeared to be a good compromise between high speed and high total plate count.