Instrumentation for capillary electrochromatography.

摘要: One of the reasons for immense interest in capillary electrochromatography (CEC) is its feature to combine chromatographic selectivity with high efficiency and miniaturization potential electrophoresis (CE). The capability commercial CE instruments run CEC has enforced readiness users researchers work on this separation technique. Nevertheless, fully exploit CEC, a routine device can certainly not fulfill all requirements. Two different approaches have been made overcome problem. first was modify various demands. Pressurization packed prevent "air" bubble formation, gradient elution capabilities thermostating devices allowing greater flexibility column designs implemented several manufacturers. A completely approach development modular laboratory-made instrumentation dedicated special In order increase mobile phase velocity thus speed analysis availability voltages higher than 30 kV accomplished some these devices. Gradient achieved by either coupling LC systems or an electroosmotic generation changing eluent composition. When pressure applied between both ends addition voltage gradient, hybrid HPLC results. This mode named pressure-assisted (PEC). Either equipped additional pumps are suitable PEC. sensitivity UV detection rather poor due short optical path length on-column techniques. cell design enhanced light presented further principles like, e.g., fluorescence mass spectrometry discussed.