Sensitive and robotic determination of bromate in sea water and drinking deep-sea water by headspace solid-phase micro extraction and gas chromatography-mass spectrometry

► This study is the first analysis method with HS SPME GC-MS of bromate. ► Selection of reagent and fibre, reaction temperature/time and pH were optimized. ► The best reagent and fiber is 2,6-DMP and CAR-PDMS. ► LOD and LOQ in sea water were 0.016 and 0.051 μg L−1 and RSD was less than 7.0%.