New assessments of dispersion in micellar electrokinetic chromatography

✍ Scribed by Joe M. Davis

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 226 KB
• Volume: 10
• Category: Article
• ISSN: 1040-7685
• DOI: 10.1002/(sici)1520-667x(1998)10:6<479::aid-mcs3>3.0.co;2-d

✦ Synopsis

A recent theory for plate number N in micellar electrokinetic chro-Ž . matography MEKC is reevaluated using more accurate measurements of micellar diffusion coefficients and instrumental contributions to dispersion. These measurements are determined using theory outlined here from the low-field dispersion of peaks of micellar markers. The theory for N accurately predicts the experimental N 's of weakly and intermediately retained analytes over wide ranges of field strength and concentration of the surfactant, sodium dodecylsulfate. The departure from theory of experimental N 's of highly retained species developed at high field strengths in buffers having high surfactant concentrations is shown by additional theory to be consistent with the radial variation of micellar electrophoretic mobility resulting from Joule heat. These calculations are the most accurate reported to date that reconcile with theory the observed high-field dispersion of highly retained neutral compounds in MEKC.