2961
Anal. Chem. 1984, 56,2961-2963
Field Determination of Bromide in Water H a j n a F. Dobolyi
T h e Dexter Corporation, Mogul Division, P.O. Box 200, Chagrin Falls, Ohio 44022
A slmpie and rapld colorlmetrlc determination for bromlde in water, especially useful for fleid test procedures, Is descrlbed. The applicable concentratlon range Is 0.06-5.0 mg/L bromide. The bromide is oxidized by peroxymonosulfate (Oxone) to bromine, which then reacts wlth phenol red at pH 4.6-4.7. t h e developed yellow-to-blue color Is measured colorlmetrlcally at 590 nm. Fading Is avoided by stopping the reaction afler color development wlth thiosulfate. Ammonlum sulfate Is used to mask chloride Interference up to 1000 mg/L concentratlon.
Table I. Effects of Other Substances
substance
concn, mg/L
Ca2+
1000 1000 5 2.5 10 1000 1 10 5 20 200 500 500
c1-
cu2+ Fe2t Fe3+ HC03Hg2+ 1-
Mn2+ "4'
NO;
Bromide may occur in varying amounts in well water and groundwater supplies as a result of seawater intrusion in coastal areas or from industrial discharges. The use of bromide-containing biocides for cooling water applications is also getting to be more and more important. To check for possible contamination or biocide treatment level a simple, rapid analytical method is presented for determining relatively small amounts of bromides. It has been especially adapted for field testing. The method can be also applied when chloride levels are relatively high (
