Electric Resistance Variation of Packing Materials in Capillary Electrochromatography by Using Fluorinated-Bonded Silica and Octadecylsilane Phases

The linear relationship between electric resistance of the packed column for capillary electrochromatography and applied voltage was observed in several different effluents and packing materials (fluorinated-bonded silica and octadecylsilane). These linear relationships had different slope values which depended on the charges on the surface of the stationary phase. If there are the negative charges on the stationary phase during the application of the electric field, the slope was negative value as observed in the fluorinated-bonded silica packed column. On the other hand, the slope was positive value in the fluorinated-bonded silica packed column using 0.1% tetrabutyammonium chloride as an effluent. The inclination of the linear relationship between the electric resistance and applied voltage also depended on the kind of the effluent, the concentration of effluent and the ratio of the organic modifier used. In the case of octadecylsilane packed column, the electric resistance of the column did not depend on the applied voltage. The relationship between the electric resistance and the electroosmotic mobility was also studied.