Bromate and bromide are often found in potable waters at trace levels, the origins of bromate come from the disinfection process of waters that also contain bromide
Waters that contain the naturally occurring bromide are usually found close to the coast as sea water contains high levels of bromide.
The mechanism by which bromate is formed is generally quite complicated but bromide reacts in a multi step manner with ozone and OH radicals to form bromate.
Bromate is a common contaminant in sodium hypochlorite production and when bleach is used as a disinfectant can enter the drinking water supplies.
Bromate has been known to be a suspected carcinogen since 1990 and so its presence is carefully monitored and regulated; currently the European Community has a maximum contaminant level of 10ug/l in potable waters.
Historically ion chromatography (IC) with conductivity detection has been used to quantify the anions bromate and bromide at levels around the consent limit, or if only bromate is required then UV-vis detection with post column reagent can be employed.
Typically bromate is present at lower levels than bromide.
IC over the last decade has grown hugely in terms of the number of applications that it is now utilised for and has been proven to be a robust technique capable of achieving accurate and reliable results.
By coupling the IC with a mass spectrometer (MS) the hyphenated technique (IC-MS) gives an increase in sensitivity by reduction of the matrix interferences to an absolute minimum.
The use of a suppressed Metrohm IC and an Agilent MS all fully controlled by Agilent ChemStation software allows traces of bromate and bromide in drinking water to be quantified together with a detection limit of 0.1ug/l for each analyte, IC-MS offers the user absolute peak confirmation with no analytical uncertainty.
The bromide concentration can be used to model and predict the risk of bromate formation due to its role as a precursor.
A typical instrument configuration would be the Metrohm MIC 2 Advanced Modular IC System coupled with 1100 series Agilent MS.
The channel partnership between Metrohm and Agilent provides an IC-MS solution that is streamlined for operation and one that can easily be maintained.
The reliability and robustness of the Metrohm suppressor - still the only chemical suppressor available with a ten year warranty as standard - and the solvent compatibility of the Metrohm IC allow for superior detection and performance compared to other available systems.
Application support and continual quality of results day in day out is unrivalled as you would expect from two world leaders like Metrohm and Agilent.
