Abstract
A multi‐functional open‐tubular (OT) column covalently modified with [3‐(phenylamino)propyl]trimethoxysilane (PPTMS) via a single‐step silanization reaction has been developed, and employed for alkaloids and aromatic acids analytes by CEC. Both anodic and cathodic EOF could be gained in the PPTMS‐bonded column, and anodic EOF was exhibited when the pH of running buffer was less than 8.0. Using thiourea as the EOF marker, a satisfactory column stability was denoted, and the RSD values for migration time and peak area were gained at 0.5 and 3.7% (intra‐day, n=5), 1.7 and 5.6% (inter‐day, n=3), 3.9 and 5.8% (column‐to‐ column, n=16 in four batches). With anodic EOF mode (pH=2.0 of 10 mmol/L phosphate buffer), favorable separations of cationic alkaloids (viz. uridine, adenosine, cytidine, adenine, cytosine) were successfully achieved with column efficiencies ranging from 95 000 to 187 000 plates/m, and the undesired adsorption on the inter‐wall of capillary column could be avoided. Besides, six anionic aromatic acids could be also separated efficiently in the co‐electroosmotic mode with anodic EOF. And high efficiencies ranged from 176 000 to 235 000 plates/m were gained with a good repeatability. PPTMS‐bonded capillary column might be used as an alternative functional medium to physical coating capillary column for the analyses of aromatic organic acids and bases.