Measure bromate photometrically – simple method, reliable results
Water treatment methods are routinely used to ensure a safe drinking water supply. However, these processes can sometimes lead to unwanted side reactions that introduce compounds, such as bromate, into the water. According to the German drinking water regulation the limit for bromate is 10 µg/l. The measurement of the bromate is described in ISO 15061:2001 and is used in Germany too. One of the possible methods for example is using ion chromatography with conductivity detection to quantify bromate.
Ion chromatography has disadvantages
As a method for measuring bromate, ion chromatography has successfully been used, but it has some disadvantages. These include the high cost of the equipment and the complex procedure used to measure bromate. Co-elution of bromate with for example chloride can occur and this leads to interferences of the analysis. To circumvent this problem, special separation techniques can be used, such as a high-capacity anion exchanger or sample pretreatment. Bromate can then be measured using conductivity detection.
Photometry as Alternative method
Merck Millipore has developed a method using photometry to measure bromate. The method is based on the reaction of 3,3'-Dimethylnaphtidin with iodide and bromate to produce a red radical cation, whose absorbance is determined photometrically. The more bromate contained in the sample, the more intense the color at the end of the reaction time.
Both methods deliver equal accuracy
Ion chromatography and photometry methods were compared using known standards as well as test samples. Measurements showed good agreement with the standards and with each other. The simplicity and low cost of using photometry make it a very desirable method for measuring bromate.
No calibration curve needed
Using classical photometry, a calibration curve must first be done in order to determine the concentration of bromate in the unknown sample. Using a Merck Millipore Spectroquant® photometer, you can completely avoid the time consuming step of preparing a calibration curve. The Spectroquant® instruments are pre-programmed with a calibration curve for accurate determination of bromate levels in your sample from 0.003 – 0.120 mg/l.
Simple photometric application
The sample preparation and bromate analysis is described in a detailed application note from Merck Millipore. The sample is first concentrated for increased sensitivity, then mixed with reagents as specified in the application note. Sample is then incubated for 30 minutes to allow color development followed by bromate measurement using a Spectroquant® photometer. Request your copy of the application by contacting Merck Millipore.
Accurate results + easy protocol – great reasons to trust your bromate analysis to Spectroquant® photometers.
Merck Millipore has long been recognized as a leader in water testing. Merck Merck Millipore’s Spectroquant® system features instruments and test kits for water quality testing – everything you need for certified quality analysis in your lab. As regulations and methods change, Merck Merck Millipore remains at the forefront. In addition to offering new test kits, we regularly supply free of charge software updates for the Spectroquant® instruments. Our commitment doesn’t stop there. We believe you should get the most from your Spectroquant® instrument. By developing alternative methods, we strive to save you time while still delivering accurate, reliable results. You don’t need ion chromatographic equipment to measure bromate. You can do it with the Spectroquant® photometer. Request your copy of the application today.