Qu Q, Tang X, Mangelings D, Wang C, Yang G, Hu X, Yan C. Control of electroosmotic flow by a cation additive to enhance the separation of amino acids by micellar electrokinetic chromatography.
J Chromatogr B Analyt Technol Biomed Life Sci 2007;
853:31-7. [PMID:
17418648 DOI:
10.1016/j.jchromb.2007.02.061]
[Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2006] [Revised: 01/03/2007] [Accepted: 02/23/2007] [Indexed: 10/23/2022]
Abstract
The effect of a divalent cation (Mg2+) and 3 monovalent cations (Na+, Li+, and K+) as buffer additives on the electroosmotic flow (EOF) was investigated in order to improve the separation performance of p-acetamidobenzenesulfonyl fluoride (PAABS-F) derivatives of 20 standard amino acids by micellar electrokinetic chromatography (MEKC). The EOF can be decreased with increasing concentration of cations with the order of cations as Mg2+>K+>Na+>Li+. However, it was found that the resolution cannot be improved easily using a buffer cation which is more capable of decreasing the EOF. Taking the migration time, resolution, and peak shape into account, Na+ is the best buffer additive, although the EOF decreased most using Mg2+. Using 20 mmol/L borate at pH 9.3 containing 140 mmol/L SDS and 20 mmol/L Na+ as electrolyte, 20 standard amino acids were successfully separated within 14 min.
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