FLOW INJECTION-CAPILLARY ELECTROPHORESIS

LIMITATIONS OF CE Despite the multiple and outstanding advantages of CE as a separation technique, including a wide range of applicable analytes, high column efficiency and resolution, low sample and electrolyte consumption, and short analysis times, some generally recognized limitations still affect its broad acceptance in routine applications. The main limitations of conventional CE may be summarized as: (a) Discontinuous mode of sample introduction (electro-kinetic, gravitational), even automated, confines the sample throughput and precision. (b) The electro-kinetic mode can “bias” sample introduction; sample components with higher electrophoretic mobilities are preferentially introduced over those with low mobilities. (c) Low sensitivity in terms of the concentration with photometric detection owing to the short light path. (d) Difficulties with samples containing large amounts of proteins and macromolecules when directly injected into the separation capillary, owing to fouling of the capillary walls by adsorption.