Packing columns for capillary electrochromatography

Considering the current interest in capillary electrochromatography (CEC), performed in packed columns, we present the different methods used to pack capillary columns for use in CEC. General considerations on column packing are given and the column fabrication process is discussed in sufficient det ail to allow instruction to those who are not experienced in the field. Fiv e different packing methods are discussed to deliver packing material into the capillary column from a practical view point: slurry pressure packing, packing with supercritical CO2, electrokinetic packing, using centripetal f orces, and packing by gravity. Entrapment of particulate material by sinter ing and sol-gel technology is also mentioned. Although slurry pressure pack ing procedures are most common, higher separation efficiencies are obtained using other packing approaches. Electrokinetic packing seems to be the sim plest technique to deliver the packing material into the capillary columns. Nevertheless, as with the other packing techniques, skill and experience a re required to complete all the steps involved in the fabrication of packed columns for CEC. (C) 2000 Elsevier Science B.V. All rights reserved.