Drinking water oxyhalides

Determination of Inorganic Oxyhalide Disinfection By-products in Drinking Water using Ion Chromatography with the Addition of a Postcolumn Reagent for Trace Bromate Analysis... 

Hautman DP, Bolyard M. 1992a. Analysis of oxyhalide disinfection by-products and other anions of interest in drinking water by ion chromatography. J Chromatogr 602(l-2) 65-74. 

Weinberg HS, Yamada H. 1998. Post-ion-chromatography derivatization for the determination of oxyhalides at sub-ppb levels in drinking water. Anal Chem 70 1-6. 

Detection limit. A sensitive chromatographic method was developed to measure sub-part-per-billion levels of the disinfectant by-products iodate (I03), chlorite (C I02 ), and bromate (BrOf) in drinking water. As the oxyhalides emerge from the column, they react with Br to make Brj, which is measured by its strong absorption at 267 nm. For example, each mole of bromate makes 3 mol of Br by the reaction BrOj" + 8Br + 6H+ —> 3Brj + 3H20. 

SOURCE H. S. Weinberg and H. Yamada, Post-Ion-Chromatography Derivatization for the Determination of Oxyhalides at Suh-PPB Levels in Drinking Water, Anal. Chem. 1998, 70,1. 

As a result of the disinfection of drinking water by means of ozone, chlorine dioxide, chloramine, and chlorine, a variety of disinfection byproducts may occur in drinking water, including oxyhalides, haloacetic acids, and halogenated AEO and APEO metabolites (Ch. 8.4.2). The LC-MS analysis of disinfection byproducts in drinking water was recently reviewed by Zwiener and Richardson [65]. 

AS9HC M-L 190 Oxyhalides, bromide, bromate in drinking water. Solvent-compatible. 

Exactly what is the analytical problem and what is the minimum analytical information needed to provide a reasonable answer In this connection it is well to categorize the type of analysis desired oxyhalides in drinking water, arsenic speciation in drinking water, speciation of chromium in plating baths, etc. 

Treated waters for domestic use are routinely analyzed using IC for both naturally present common inorganic anions and trace anionic contaminants, several classes of which actually originate as by-products of the treatment processes themselves. Oxyhalides, which originate from various drinking water disinfection processes, such as chlorination and ozonation, can be found present in finished drinking... 

Table 1 lists some of the IC methods prescribed by the US EPA for the analysis of drinking water including several oxyhalide disinfection by-products... 

Determination of inorganic anions and oxyhalides in drinking water by 1C Determination of inorganic cations in drinking water by 1C Determination of perchlorate in drinking water by 1C... 

Determination of inorganic oxyhalide disinfection by-products in drinking water using 1C with the addition of a postcolumn reagent for trace bromate analysis... 

In this connection, many drinking water utilities are changing their primary disinfectants from chlorine to alternative disinfectants, such as ozone, chlorine dioxide, and chloroamines, which reduce regulated trihalomethanes and some organochlorine compound levels but, at the same time, often increase levels of other potentially toxicologi-cally important compounds, such as inorganic oxyhalide by-products (bromate, chlorite, and chlorate). Some of them have been classified as probable human carcinogens. 

Bromate is a disinfection by-product that is produced from the ozonation of source water that contains naturally occurring bromide, whereas chlorite and chlorate are produced as a result of using chlorine dioxide as a disinfectant. Recently, bromate has become the most important inorganic oxyhalide by-product, and its concentration in drinking water has to be controUed. Another chaUenge is seawater, which represents a vay difficult matrix for the analysis of trace ionic constituents, because chloride, sulfate, and sodium are the primary ions and they are presort at extremely high concentrations. " ... 

Inorganic Oxyhalide By-Products in Drinking Water Ion Chromatographic Methods... 

Recently, bromate has become the most important inorganic oxyhalide by-product, and its concentration in drinking water has to be controlled. Furthermore, the subjects of interest and advanced research are chlorite and chlorate. Bromates are formed when water containing bromide is ozonated. The concentration of bromide in natural waters varies, typically, between 10 and 1000 p-g/L. From the theoretical and practical point of view, it can be seen that bromate formation can be influenced by many parameters, such as ozone dose, water pH, temperature, and indigenous concentration of bromide. ... 

The U.S. EPA Method 321.8 specifies the use of an anion-exchange column and detection of bromate using inductively coupled plasma-mass spectrometry (ICP-MS) in the atmospheric pressure mode. The U.S. EPA Method 326.0 has been developed for the analysis of ultra trace bromate concentrations in drinking water using a postcol-unm derivatization reaction with Mo(VI). A review of the methods of IC determination of inorganic disinfection byproducts published by U.S. EPA has been conducted by Hautman et al. The ISO standards for the determination of inorganic oxyhalides in water are smnmarized in Table 1, and U.S. EPA methods recommended are listed in Table 2. 

All the three groups of IC methods recently developed (based on conductivity, UV/Vis, and MS detection modes, respectively) yield comparable results and comply with the requirements of the international directives concerning inorganic oxyhalide by-products in drinking water. " The future application and choice of a method will depend on the equipment available in the laboratories, as well as the number and kinds of samples to be analyzed. 

AS 19 High Oxyhalides and inorganic anions. Key application is trace bromate in ozonated drinking water... 

Figure 10.28b illustrates the performance of the method for the determination of oxyhalides and bromide in a drinking water sample spiked with chlorite, bro-mate, bromide, and chlorate at levels of 108, 11.3, 36, and 72pg/L, respectively. Quantitative recoveries between 96 and 107% were obtained for all anions. As can be seen for the UV/Vis trace in Figure 10.28b, no response is observed for the large peak of chloride (c = 20 mg/L) that elutes immediately after bromate. 

Thermo Fisher Scientific (1997) Ion Chromatography Determination of Oxyhalides and Bromide at Trace Level Concentrations in Drinking Water Using Direct Injection. Application Note No. 

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