Column technology for capillary electrochromatography

Column technologies for capillary electrochromatography( CEC) are reviewed. To achieve high efficiency, the inner diameters of open-tubular and packed columns should be less than 25 and 200 mum, respectively. To obtain acceptable separation speed under typical CEC conditions (e.g. 30 kV, 1 mm s(-1) electroosmotic flow velocity, and 2-4 x 10(-8) m(2) V-1 s(-1) electroosmotic mobility) the column lengths for open-tubular and packed columns should be less than 120 and 60 cm, respectively. Capillary CEC columns are generally classified into three types: packed, open-tubular, and continuous-bed or monolithic. The various column preparation procedures and the advantages and disadvantages of each column type are discussed in detail. (C) 2000 Published by Elsevier Science B.V.