[Surveillance of Chromium(VI) Concentrations in Mineral Water Products]

We developed and evaluated a method of quantifying chromium(VI) in mineral water (MW). After a performance evaluation, we performed a surveillance of chromium(VI) concentrations in 150 kinds of MW products purchased from markets in 2016. Recovery rates, as examined by using 150 spiked samples prepared from the purchased MW products, ranged from 93 to 107%. These results strongly suggest that the validated method is suitable for quantifying chromium(VI) in MW. Chromium(VI) was detected in 65 kinds of MW products; the detection rate was 43%. The minimum concentration of chromium(VI) was 0.0001 mg/L and the maximum was 0.0019 mg/L. The median value of chromium(VI) concentration was 0.0003 mg/L. In most of the products in which chromium(VI) was detected, the concentration ranged from 0.0001 to 0.0002 mg/L. No products were found with concentrations higher than the value (0.05 mg/L) set by the Food Sanitation Law as the specification for MW.