Flow injection-capillary electrophoresis coupling to automate on-line sample treatment for the determination of inorganic ions in waters

An automated interface for coupling flow injection (FI) systems with capillary electrophoresis (CE) has been developed and tested to combine the sample preparation capabilities of Fl systems with the separation and determination provided by CE. To demonstrate the usefulness of such integration, two automated methodologies have been developed for on-line multiparametric monitoring of both anionic and cationic species in a water purification plant, to provide continuous control of the quality of the water. The concentration of anions such as chloride, nitrate, nitrite, sulphate and phosphate, of cations such as sodium, potassium, ammonium, calcium, magnesium, iron, and of heavy metals at trace level (e.g., manganese, aluminium, lead, cadmium), preconcentrated in the flow system, is provided in an integral manner by the operational procedure proposed in this paper. The determination limits established by legislation in OECD countries have been achieved demonstrating the potential of CE to be applied to real samples. (C) 1997 Elsevier Science B.V.