Pressurized flow driven electrochromatography using fluorinated-bonded silica

Capillary electrochromatography using fluorinated-bonded silica (Fluofix(R) ) under pressurized flow was demonstrated to be applied to the separation o f charged compounds and neutral compounds. The reduction and extension of t he elution time due to the application of high voltage were demonstrated. T he typical variation of elution order of the samples was observed. The redu ction of electroosmotic flow mobility (mu(osm)) from the linearity was comp aratively observed on the two different effluents when the voltage was appl ied to the column. The alternations of retention factors of neutral compoun ds due to applied voltage are observed and the retention mechanisms of the compounds are discussed. With the same electrochromatographic condition and pH of the effluents used, the electroosmotic flow velocity (V-osm) magnitu de of the phosphate buffer effluent was higher than the ammonium acetate ef fluent system. Thus the ammonium acetate might suppress the potentially enh anced negative charge of the stationary phase. (C) 1999 John Wiley & Sons, Inc.