Significance and Use
4.1 The oxyhalides chlorite, chlorate, and bromate are inorganic disinfection by-products (DBPs) of considerable health risk concern worldwide. The occurrence of chlorite and chlorate is associated with the use of chlorine dioxide, as well as hypochlorite solutions used for drinking water disinfection. The occurrence of bromate is associated with the use of ozone for disinfection, wherein naturally occurring bromide is oxidized to bromate. Bromide is a naturally occurring precursor to the formation of bromate.
Scope
1.1 These multi-test methods cover the determination of the oxyhalides—chlorite, bromate, and chlorate, and bromide, in raw water, finished drinking water and bottled (non-carbonated) water by chemically and electrolytically suppressed ion chromatography. The ranges tested using these test methods for each analyte were as follows:
|
| Range | Sections |
| Test Method A: |
| |
| Chlorite | 5 to 500 µg/L |
|
| Bromate | 1 to 25 µg/L |
|
| Bromide | 5 to 250 µg/L |
|
| Chlorate | 5 to 500 µg/L |
|
| Test Method B: |
| |
| Chlorite | 20 to 1000 µg/L |
|
| Bromate | 1 to 30 µg/L |
|
| Bromide | 20 to 200 µg/L |
|
| Chlorate | 20 to 1000 µg/L |
|
1.1.1 The upper limits may be extended by appropriate sample dilution or by the use of a smaller injection volume. Other ions of interest, such as fluoride, chloride, nitrite, nitrate, phosphate, and sulfate may also be determined using these test methods. However, analysis of these ions is not the object of these test methods.
1.2 It is the user’s responsibility to ensure the validity of these test methods for waters of untested matrices.
1.3 These test methods are technically equivalent with Part B of U.S. EPA Method 300.1,2 titled “The Determination of Inorganic Anions in Drinking Water by Ion Chromatography.”
