ION-EXCHANGE FLOW-INJECTION SPECTROPHOTOMETRIC SIMULTANEOUS DETERMINATION OF TRACES OF BROMIDE AND IODINE IN SOME CHINESE STANDARD SAMPLES

An ion exchange flow injection method is presented for the simultaneou s determination of bromide and iodide based on the catalytic reaction during the oxidation of Pyrocatechol Violet by hydrogen peroxide in st rongly acid solution. Bromide and iodide in sample solutions are conce ntrated when they flow through the ion exchange column; they are-remov ed and separated with sodium nitrate eluant flowing through the column , and are monitored spectrophotometrically at 555 nm. All possible ani onic interferences were studied, The procedure has been applied succes sfully to the determination of bromide and iodide in some Chinese stan dard reference samples, The limits of detection are 0.2 ppm and 0.4 pp m of bromide and iodide respectively in soils and stream sediments.