Tritium concentration in the modern commercial DO reagents.

We investigated the tritium concentration in commercial modern DO reagents frequently used in nuclear magnetic resonance analysis for analytical chemistry and in environmental tracer testing. The concentration of tritium in 11 DO and 1 HO reagents ranged from 61 Bq/L (5 × 10 TU) to 2.5 × 10 Bq/L (2 × 10 TU) in order of magnitude. The tritium concentration in the DO reagents have increased with the increasing purity of DO. The tritium concentration in all reagents was an order of magnitude greater than that in the surface waters at the Fukushima off-site of the Fukushima Daiichi Nuclear Power Plant after the accident in 2011 and in precipitation during the nuclear test era. However, the concentration of the tritium was lower than the regulatory limit for the concentration of tritium in drinking water accepted by the World Health Organization guidelines. The internal exposure effects from drinking the tritium water, which is contaminated by the tritium condensed in the reagent production processes, were negligible, even if the reagent was used in the environmental tracer test.