Bromine is an oxidant and can be used as sanitizer, especially for the disinfection of swimming pools, spas, and cooling tower water. Bromine determination in aqueous samples is performed mainly to ensure effectiveness of the disinfection and to prevent negative health impact on humans.
According to ANSI/APSP/ICC-11 Standard for Water Quality in Public Pools, the ideal range for bromine is 2 to 4 ppm for pools and 4 to 6 ppm for spas.1
Bromine is not used in public drinking water treatment, but it is a registered disinfectant by the U.S. Environmental Protection Agency for drinking water applications aboard some navy ships and oil drilling platforms.2 According to 40 CFR Section 180.519 the bromine level shall not exceed a final concentration of 1.0 ppm in the treated water.3
This Application Note describes the method that was formerly available as Spectroquant® Bromine Test (1.00605) which is now discontinued. The method is furthermore available as preprogrammed method in the Spectroquant® photometers and colorimeters Prove 100/300/600, Nova 60 and Move 100 and can be performed with the use of the reagent of Spectroquant® Chlorine Test (1.00598).
The reagent Cl2-1 of Cat. No. 1.00598 Spectroquant® Chlorine Test has the identical reagent composition as the reagent Br2-1 of the discontinued Cat. No. 1.00605 Spectroquant® Bromine Test.
The method with a measuring range of 0.020 – 10.00 mg/L Br2 is suitable to determine the bromine concentration in drinking water, swimming-pool water, wastewater and disinfection solutions.
In weakly acidic solution free bromine reacts with dipropyl-p-phenylenediamine (DPD) to form a red-violet dye that is determined photometrically.
Drinking water, swimming-pool water, wastewater, disinfection solutions
Other components in the sample - than the target analyte Br2 – may interfere with the detection chemistry described here. Some of them were checked in solutions containing 3.5 and 0 mg/L Br2. The determination is not yet interfered with up to the concentrations of foreign substances given in the table. Cumulative effects were not checked; such effects can, however, not be excluded.
For bromine measurement one of the following Spectroquant® photometers is necessary:
The Spectroquant® Prove Connect to LIMS software package provides an easy way to transfer your data into an existing LIMS system. This software can be purchased under:
Prove Connect to LIMS (Y.11086)
Pipettes for a pipetting volume of 10.0 mL
It is recommended to perform a zero adjustment for this method each new working day. Details regarding the zero adjustment can be found in the user manual of your instrument.
It is recommended to use the same cell for zero adjustment and for sample measurement. For zero adjustment fill the cell with distilled water (or water for analysis) and follow the instructions in the user manual of your instrument.
Note: Recommended before each measurement series.
To check the photometric measurement system (test reagent, measurement device, handling) and the mode of working, a freshly prepared bromine standard solution containing 5.00 mg/L Br2 (application see the website) can be used. Sample-dependent interferences (matrix effects) can be determined by means of standard addition.