Dual-opposite-injection CZE: theoretical aspects and application to organic and pharmaceutical compounds.
Several important figures of merit (migration time, efficiency, resolution, resolution per unit time, and electrophoretic selectivity) are quantitatively compared for the first time for conventional CZE and dual-opposite-injection CZE (DOI-CZE). Aspects of DOI-CZE relevant to the separation of organic and pharmaceutical ions (MW>120 Da) are also discussed. Two new approaches to resolve the codetection of anions and cations, hydrodynamic flow-modified DOI-CZE and polarity reversal in combination with asymmetric detector window positioning, are compared with the method of preliminary transport, a variable procedure within sequential sample introduction, using a six-component sample of organic and pharmaceutical compounds. The advantages of DOI-CZE for the simultaneous analysis of organic/pharmaceutical anions and cations are illustrated in a direct comparison of conventional CZE and DOI-CZE for the separation of a ten-component mixture of pharmaceutical ions (five ionized acids and five ionized bases).
Weekley
Brian S
BS
Analytical R&D, Pfizer Global Research and Development, Ann Arbor, MI, USA.
Foley
Joe P
JP
D000838:Anions / Q000737:chemistry; D002412:Cations / Q000737:chemistry; D019075:Electrophoresis, Capillary / Q000379:methods*; D017022:Flow Injection Analysis / Q000379:methods*; D009930:Organic Chemicals / Q000302:isolation & purification*; D004364:Pharmaceutical Preparations / Q000302:isolation & purification*; D012680:Sensitivity and Specificity; D012996:Solutions / Q000737:chemistry
D000838:Anions; D002412:Cations; D009930:Organic Chemicals; D004364:Pharmaceutical Preparations; D012996:Solutions