ntroduction to “ Comparison between the efficiencies of columns acked with fully and partially porous C 18-bonded silica materials ”

In the fall of 2006, Prof. Georges Guiochon entered the office of is coworkers at the University of Tennessee Knoxville (Knoxville, N, USA) to announce that he received three prototype columns hat should deserve their particular attention. The message was lear: current research investigations had to be stopped, isocratic nd gradient performances of these columns should be invesigated for small and large compounds, and their fundamental roperties should be tackled. Indeed, for the very first time, 2.7 m uperficially porous particles (SPP) had been successfully prepared nd packed in a 4.6 × 150 mm column format. Based on some rivate communications, Georges revealed that their chromatoraphic speed/resolution performances were stunning and that a erious breakthrough in the field of stationary phases could follow. SPP are made of a solid impermeable silica core surrounded by a orous shell. The concept of SPP was not new in 2006 since pelliclar particles were already imagined in the 1960s by Horvath and ipsky. Back then, the motivation was to improve the poor resoution of macromolecules which diffuse very slowly. Reducing the verage diffusion path across wide 50–100 m fully porous partiles (FPP) was a brilliant solution. These fundamentals expectations ere supported by the actual and significant reduction of the mass ransfer resistance of nucleotides along the chromatographic colmn. Later on, in the 1990s, the concept of SPP was applied to he popular 5 m particles (4.75 m solid core, shell thickness .25 m) but, due to the continuing development of smaller highurity FPP down to the sub-2 m size, the advantages of these 5 m PP rapidly disappear. In contrast, a major change was about to take place in 2006 ith the prototype 2.7 m SPP as their manufacturer (Advanced aterial Technologies, Wilmington, DE, MA) claimed that they had he same resolution power as that of the recently commercialized ub-2 m FPP, which emerged a few years earlier with the new eneration of very high pressure liquid chromatography (vHPLC) nstruments. Chromatographers would then benefit from vHPLC esolution levels using inexpensive HPLC instruments. The present aper “Comparison between the efficiencies of columns packed