[A simple method for preparing reversed-phase electrochromatographic column and its evaluation]

The packed column was prepared with a simple method by combination of vacuum filling and pressure compressing. The reproducibility of efficiency and retention time was evaluated. The mixture of thiourea and three aromatic compounds was used. RSD values of retention time were smaller than 2.2% and RSD values of efficiency were smaller than 7.5%. The influence of voltage, phosphate concentration, acetonitrile volume fraction and column temperature on the electroosmotic flow and capacity factor of neutral compounds was investigated. Acetonitrile concentration had significant effect on the electroosmotic flow and capacity factor of neutral compounds. High concentration of acetonitrile improved the elution ability. Low concentration of acetonitrile improved the resolution. Voltage, phosphate concentration, and column temperature also had effects on the electroosmotic flow and capacity factor of neutral compounds, but the effects were smaller than the concentration of acetonitrile. These results gave a guide to select separation conditions in capillary reversed-phase electrochromatography.