An electric field superimposed on a chromatographic bed, so that electroosmotic flow and electrophoretic migration act together with chromatographic retention, defines electrochromatography, most often implemented as capillary electrochromatography (CEC). The stationary phase may be a packed bed, a surface-grafted open tube, or an in situ formed porous monolith; the mobile phase is driven primarily by electroosmosis rather than by a pressure drop [1]. Rigid polymer monoliths allow independent control of pore structure and surface chemistry, which in turn set permeability, electroosmotic mobility, and chromatographic selectivity [2]. Conceptual boundaries exclude pressure-driven micro-HPLC in the same capillary, and they exclude free-zone capillary electrophoresis that lacks a stationary phase. Essential features are a charged or chargeable surface that supports electroosmosis, a stationary phase that partitions or adsorbs the solutes, and an applied voltage that generates the flow [3]. Monolithic and bead-trapping formats extend the same electrochromatographic principle from fused-silica capillaries to microfluidic channels [4].
- electrochromatography
- capillary electrochromatography
- electroosmotic flow
- polymer monolith
Analytical Chemistry and Chromatography • Spectroscopy • Chemistry • Physical Sciences
References
- Isabelle Gusev; Xian Huang; Csaba Horváth; Capillary columns with in situ formed porous monolithic packing for micro high-performance liquid chromatography and capillary electrochromatography. J. Chromatogr. A 1999, 855, 273-290, 10.1016/s0021-9673(99)00697-4.
- Eric C. Peters; Miroslav Petro; Frantisek Svec; Jean M. J. Fréchet; Molded Rigid Polymer Monoliths as Separation Media for Capillary Electrochromatography. 1. Fine Control of Porous Properties and Surface Chemistry. Anal. Chem. 1998, 70, 2288-2295, 10.1021/ac9713518.
- Hanfa Zou; Xiaodong Huang; Mingliang Ye; Quanzhou Luo; Monolithic stationary phases for liquid chromatography and capillary electrochromatography. J. Chromatogr. A 2002, 954, 5-32, 10.1016/s0021-9673(02)00072-9.
- Richard D. Oleschuk; Loranelle L. Shultz-Lockyear; Yuebin Ning; D. Jed Harrison; Trapping of Bead-Based Reagents within Microfluidic Systems: On-Chip Solid-Phase Extraction and Electrochromatography. Anal. Chem. 1999, 72, 585-590, 10.1021/ac990751n.