Feasibility of wavelength dispersive X-ray fluorescence spectrometry for a simplified analysis of bromine in water samples with the aid of a strong anion exchange disk

• Bromide and bromate were entirely retained on a strong anion exchange (SAX) disk.
• The SAX disk was used to pre-concentrate dissolved Br species from water samples.
• The SAX disk adsorbing dissolved Br was directly analyzed by WDXRF.
• The accuracy of the SAX–WDXRF method was confirmed by spike and inter-comparison tests.
• Rapid and sensitive Br analysis can be achieved using the proposed SAX–WDXRF method.

The feasibility of wavelength dispersive X-ray fluorescence spectrometry (WDXRF) for a simplified analysis of bromine (Br) in water samples with the aid of strong anion exchange (SAX) disk was assessed in this study. Dissolved Br in the water sample was pre-concentrated on the SAX disk and directly analyzed by WDXRF without an elution step. The SAX disk was capable of fully adsorbing both bromide (Br−) and bromate (BrO3−) on its surface owing to their anionic properties, regardless of the pH level of environmental samples. The SAX–WDXRF system was examined using calibration standards (i.e., SAX disks with specific amounts of Br retained; 1, 10, 50, 100 and 500 μg), and a determination coefficient of R2 = 0.9999 was yielded. The system had a low detection limit for Br (limit of detection = 0.253 μg for Br on the SAX disk) with good reproducibility (relative standard error (RSE) = 4–7%). Spike and inter-comparison tests were performed to confirm the accuracy of the proposed SAX–WDXRF method. Both tests exhibited reasonable accuracy (RSE = 3–6%). The method is simple and easy, indicating a great possibility of application in various environmental sample types, especially for which a simplified analytical system for the determination of Br is urgently required.