Outside of these areas, however, inexperience of CE and the predominance of HPLC in many analytical laboratories continue to impede uptake of the technique. This is despite the fact that for many analyses CE may be easier, faster and more cost-effective. CE is an automated analytical technique that separates species by applying voltage across buffer filled capillaries. It is generally used for separating ions, which move at different speeds when the voltage is applied depending on their size and charge. The solutes are seen as peaks as they pass through the detector and the area of each peak is proportional to their concentration, which allows quantitative determinations.
Analysis includes purity determination, assays, and trace level determinations.
Analysis times are in the region of 1-30 minutes depending on the complexity of the separation. Modern instruments are relatively sophisticated and may contain fibre optical detection systems, high capacity autosamplers, and temperature control devices. Detection is usually by UV absorbance - often with a diode array. Other commercial detectors include fluorescence detection and coupling to mass spectrometers. Inorganic ions CE can rapidly and efficiently separate inorganic ions such as metal ions and anions, for example chloride, sulphate and nitrate.