Evaluation of a dual-cyclodextrin phase variant of capillary electrokinetic chromatography for separations of nonionizable solutes
- Univ. of Tennessee, Knoxville, TN (United States)
A capillary electrokinetic chromatography technique is described that employs neutral cyclodextrins (CDs) as a primary phase, transported with electroosmotic flow, and charged CDs as an electrophoretically mediated secondary phase. Neutral, hydrophobic solutes are separated on the basis of their differential distribution between these CD phases. The technique resembles micellar electrokinetic capillary chromatography (MECC) with regard to instrumentation and the fundamental relationships for resolution and capacity factor, which are influenced by the existence of a finite elution window. Conversely, the CD technique offers unique and beneficial characteristics when compared to MECC. Efficiency, selectivity, and system retention are evaluated on the basis of separations of polyaromatic hydrocarbons (PAHs). Efficiency is comparable to that of MECC (> 10{sup 5} plates/m). The specificity associated with solute-CD inclusion complexation provides elution orders for PAHs that do not follow the hydrophobicity trends of MECC. Moreover, since the CD phases are largely noninteractive, complex CD systems can be used to enhance selectivity. Capacity factors can be altered in a convenient and predictable fashion simply by changing the CD phase ratio. The technique is rather robust with regard to the use of running buffers containing organic solvents; the effects or organic modifier and pH on system retention are demonstrated. 19 refs., 4 figs., 1 tab.
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- FG05-86ER13613
- OSTI ID:
- 81353
- Journal Information:
- Analytical Chemistry (Washington), Journal Name: Analytical Chemistry (Washington) Journal Issue: 13 Vol. 67; ISSN 0003-2700; ISSN ANCHAM
- Country of Publication:
- United States
- Language:
- English
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