Improved sensitive determination method for bromate in bread

An effective clean-up procedure was developed to determine trace levels of bromate in bread by high-performance liquid chromatography with post-column flow reactor detection. Bromate was extracted from bread with deionized pure water. After centrifugation, the supernatant was filtered through a paper filter. The filtrate was filtered through a 0.2 micron nylon filter and chloride ion was removed by an IC-SP M Ag cartridge column or On-Guard Ag cartridge column. The eluate was applied to an Oasis MAX anion exchange cartridge column. The column was washed with 20% acetic acid and water. Bromate was then eluted with 0.5% sodium nitrate solution. The eluate was determined by HPLC with post column flow reactor detection. The method had a quantitation limit of 2 ng/g in bread products. Recoveries of bromate from bread ranged from 68 to 72% at a spiked bromate level of 2-10 ng/g.