New EPA Methods for Bromate and Haloacetic Acids with the EPA Office of Ground Water and Drinking Water  

Dionex announces two recently approved methods for the determination of disinfection by products in drinking waters.

Method 302 is a two-dimensional (2-D) IC method that was developed to provide a more robust solution for drinking waters with high concentrations of anions compared to the post column method 317 and 326. Using a Reagent-Free™ IC (RFIC™) system, EPA 302.0 allows the user to just add water to each system instead of preparing eluents and unstable or toxic post-column reagents. EPA 302 uses a 2-D system setup.

1) the first system partially resolves the matrix, andremoves and traps a time segment containing bromate, and

2) reruns this time segment on a second system. Both systems only require the addition of distilled water. This method can be performed using two IC systems, or a dual ICS-3000 system. Method 302 is suitable for all waters which are regulated for bromate compliance monitoring.

EPA 557 is an alternative to methods 552.1, -.2, and -.3, which use GC/ECD based detection. The 552 methods require extensive sample preparation—laborious extraction, 2 hr. derivatization, and pH adjustment; pretreatment that can take up to 3-4 hours per sample. Alternatively, 557 is a direct injection technique with no sample preparation that uses an RFIC system and hydroxide eluent for ion-exchange separation prior to MS/MS detection. The newly developed IonPac® AS24 column provides complete chromatographic resolution for each analyte, even in high-ionic-strength waters. This allows diversion of suppression-causing anions to waste prior to entering the ESI source for exceptional sensitivity and detection.