Continuous bed columns containing sol–gel bonded large-pore octadecylsilica for capillary electrochromatography

✍ Scribed by Qinglin Tang; Naijun Wu; Milton L. Lee

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 405 KB
• Volume: 11
• Category: Article
• ISSN: 1040-7685
• DOI: 10.1002/(sici)1520-667x(1999)11:7<550::aid-mcs8>3.0.co;2-b

✦ Synopsis

Continuous bed columns containing sol᎐gel bonded large-pore octade-Ž .

Ž . cylsilica ODS particles 7 m, 4000 A were prepared by packing ODS particles into fused silica capillaries, filling the packed capillaries with siliceous sol᎐gel, curing the sol᎐gel, and drying the column with supercritical carbon dioxide. The performance of these columns was evaluated for capillary electrochromatography and compared to packed columns with the same column dimensions and packing materials, except for the sol᎐gel, using TRIS buffer in aqueous acetonitrile as mobile phase. No bubble formation was noticed in the sol᎐gel bonded ODS column with electric field strength up to 732 V cm y1 and current as high as 3.5 A. The electroosmotic flow velocity in the sol᎐gel bonded ODS column was the comparable to the mobile phase velocity used in conventional HPLC, and was 30% higher than that measured for the packed ODS capillary column. An efficiency of 5 Ž 2.20 = 10 plates per meter plate height of 4.56 m, or reduced plate height of . 0.65 was obtained for unretained thiourea with a 41r32 cm = 75 m i.d. sol᎐gel bonded large-pore ODS column, which was nearly 2 = greater than that of the packed ODS capillary column. Mixtures of aromatic amines were eluted from the column with symmetrical peak shapes, which suggested that the sol᎐gel matrix had no deleterious effect on peak shapes of solutes under experimental conditions. Based on experimental results, a model of the sol᎐gel bonded ODS column was proposed.