PREPARATION OF CONTINUOUS BEDS DERIVATIZED WITH ONE-STEP ALKYL AND SULFONATE GROUPS FOR CAPILLARY ELECTROCHROMATOGRAPHY

A simple one-step procedure for the preparation of columns for capilla ry electrochromatography is described, The nonpolar compounds (stearyl or butyl methacrylate) used for the introduction of hydrophobic ligan ds (C18, C4) are rendered water-soluble in the aqueous monomer mixture used for the synthesis of the matrix by the addition of a surfactant, This solution is sucked into a piece of fused silica tubing, the inne r walls of which are activated by methacryl groups. Following polymeri zation, the continuous bed column is ready for use, Since the bed is a ttached covalently to the tubing wall, no hit to support the bed is re quired, which simplifies the preparation of the column. In addition, a frit can easily become clogged and is often a site for the generation of air bubbles. Some new approaches to increase the resolution and sh orten the analysis times in electrochromatography are suggested and de monstrated experimentally, such as sharpening the starting zone, emplo ying gradient elution, or adding SDS (below cmc) to the mobile phase, Separation of five polycyclic aromatic hydrocarbons can be achieved in 5 min in a 25-mu m-i.d. column.