In March 2019, bottled water of a brand was recalled in large quantities because the carcinogen bromate exceeded the standard. As soon as the news came out, everyone was filled with doubts. What is bromate?Is bromate really carcinogenic? Do all bottled water contain bromate?

"What is bromate?"

Ozonation is an effective bactericidal and bacteriostatic method for packaging water.Bromate is a compound formed by the gradual oxidation of bromine ions in natural water by ozone.The concentration of bromate mainly depends on the concentration of bromide ion, ozone and the contact time between ozone and water.

"Is bromate really carcinogenic?"

The International Agency for Research on Cancer (IARC) has designated bromate as a 2B carcinogen. In China's drinking water monitoring project, bromate content should not exceed 0.01mg/L.

Category II Carcinogen List of (IARC)

"Does all bottled water contain bromate?"

No！

Bromate occurs in water only when the following two conditions are met at the same time.

(1) The water itself contains a large amount of bromide.

(2) Use high concentration ozone to sterilize. 

Natural water and mineral water mostly contain bromides. Therefore, if ozone is used to sterilize them, a combination of the two factors will produce a higher concentration of bromate.

"How to detect the content of bromate in bottled water?"

Ion chromatography is the preferred method for the determination of inorganic anions. In GB 8538-2016, ion chromatography is the only method for the determination of bromate radical (BrO3-).

Recommended configuration conditions

l IC type:CIC-D160(built-in eluent generator)

l Analysis column:SH-AC-11

l Guard column:SH-G-1

l Eluent:NaOH gradient elution

l Flow rate:1.0mL/min

Sample test chromatogram

Table1  Gradient elution chromatogram of 7 kinds of common anions and bromate radical