New trends in capillary electrochromatography techniques (Chapter 5)

Capillary electrochromatography (CEC) is an analytical technique performed in capillaries with a thin internal diameter containing a stationary phase (SP). Compounds are moved into the column to the detector by a strong electroosmotic flow (EOF) generated by the application of a high voltage (10-20 kV). The separation mechanism involved in the analysis process is based on both chromatographic and electrophoretic principle. Therefore, it offers high efficiency and high selectivity typical of capillary electrophoresis and high performance liquid chromatography (HPLC), respectively. CEC has been widely studied and the literature covers several aspects related to this miniaturized technique such as theory, instrumentation, selection and use of different stationary phases, applications etc. The aim of this chapter is to present the main features of CEC and its potentiality for the separation of compounds of different nature (uncharged and charged species). Instrumentation currently used, considering the detectors and the coupling with mass spectrometry (MS), optimization of experimental conditions, the different SPs have also been discussed. Finally, some selected applications in the field of drug analysis, protein, enantiomers, nutraceutical compounds separation are described.