Effects of methanol-modified mobile phase on the separation of isotopically substituted compounds by micellar electrokinetic capillary chromatography

✍ Scribed by Michelle M. Bushey; James W. Jorgenson

• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: English
• Weight: 533 KB
• Volume: 1
• Category: Article
• ISSN: 1040-7685
• DOI: 10.1002/mcs.1220010304

✦ Synopsis

Near-baseline resolution of dansylated methylamine and dansylated methyld,-amine can be achieved by micellar electrokinetic capillary chromatography (MECC) utilizing a 25-mM sodium dodecylsulfate pseudostationary phase and a mobile phase containing 4.9 M methanol. This study examines the role of methanol on this separation by looking at its effects on to, tr, r,, and resolution over four methanol concentrations, 0 M, 2.5 M, 4.9 M, and 7.4 M. The 4.9 M methanol buffer proves to be the best for optimizing the resolution of these two extremely similar compounds. Because of the high organic content of the mobile phase, it is unreliable to determine t, based upon the migration time of a single species. A method for determining t, based upon a homologous series of standards is presented and examined over the four methanol concentrations. Plots of log i' versus carbon number yield straight lines with similar slopes for each of the four buffer systems, indicating that this procedure is a good method for t, determination.