The impact of extra-column band broadening on the chromatographic efficiency of 5 cm long narrow-bore very efficient columns

Small columns packed with core-shell and sub-2 mu m totally porous particles and monolith columns are very popular to conduct fast and efficient chromatographic separations. In order to carry out fast separations, short (2-5 cm) and narrow-bore (2-2.1 mm) columns are used to decrease the analyte retention volume. Beside the column efficiency, another significant issue is the extra-column band-spreading. The extra-column dispersion of a given LC system can dramatically decrease the performance of a small very efficient column. The aim of this study was to compare the extracolumn peak variance contribution of several commercially available LC systems. The efficiency loss of three different type 5 cm long narrow bore, very efficient columns (monolith, sub-2 mu m fully porous and sub-2 mu m core-shell packing) as a function of extra-column peak variance, and as a function of flow rate and also kinetic plots (analysis time versus apparent column efficiency) are presented. (C) 2011 Elsevier B.V. All rights reserved.