Analysis of organic and non-organic arsenious or selenious compounds by capillary electrophoresis

High-performance capillary electrophoresis appeared as an efficient tool for the separation of organic and non-organic arsenious or selenious compounds. The effect of operating conditions, such as pH, concentration of the background electrolyte and addition of surfactant to the background electrolyte in order to reverse the electroosmotic flow, has been studied. This separation technique leads to low levels of detection for both classes of compounds, if mass sensitivity is considered (several tens of pg), but it requires quite concentrated samples (several mg 1^–1), if concentration sensitivity is considered.