The disinfection of water can lead to the formation of potentially carcinogenic compounds referred to as disinfection byproducts (DBP). Bromate, an oxyhalide DBP, is currently regulated in US drinking waters with a maximum contaminant limit (MCL) of 10 µg/L. Other parts of the world have the same limit and there is a limit of 3 µg/L for bottled mineral water in Europe. Recently there has been a discussion of lowering the 10 µg/L limit and this could require more sensitive analytical methods.  The most commonly applied analytical technique for measurement of oxyhalides in drinking water is ion chromatography with suppressed conductivity detection (IC-CD). Suppressed conductivity detection has low selectivity as many compounds are ionic and thus can be detected by CD. This study developed a method to determine bromate in water by coupling IC with single quadrupole mass spectrometry (IC-MS). This coupling delivers both CD and MS detections. The IC-MS method described here was compared with the established US EPA Method 300.1 Part B (IC-CD) for bromate analysis. The IC-MS method offers significant advantages over the traditional IC-CD method in terms of sensitivity and selectivity. The limit of detection (LOD) of bromate was 0.04 µg/L, which is an improvement of about 8-10 times compared to IC-CD. IC-MS also offers a more confident identification, particularly for complex matrices. This method was then applied to bottled and drinking water samples. The recovery of bromate in water samples was 95-105%. This method can simultaneously determine other oxyhalides (chlorite, chlorate) and bromide and thus is able to deliver Method 300.1 Part B data, confirm peak identification, and provide a more sensitive detection of bromate. Coupling MS with CD takes advantage of the strengths of each detector, high sensitivity of MS detector, and wider linear range of CD detector.

Determination of bromate in drinking water using ion chromatography-single quadrupole mass spectrometry

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.