SEPARATION OF BROMIDE, BROMATE, IODIDE, IODATE, NITRITE, NITRATE AND SELENITE ANIONS BY CAPILLARY ZONE ELECTROPHORESIS

Capillary zone electrophoresis (CZE) has been used for the separation of bromide, bromate, iodide, iodate, nitrite, nitrate and selenite anions. The separation was achieved using a fused silica capillary (72 cm long x 50 mum i.d.) filled with an acidic phosphate buffer (pH = 3, 25 mmol/1), and with on-column UV detection at 200 nm. The influence of different experimental parameters such as pH, ionic strength and voltage, was studied. The nitrate concentration of a Rhine water sample was then determined under selected conditions and the results were compared to those obtained by high performance ion chromatography (HPIC).