2021 年 37 巻 11 号 p. 1517-1523
We present an analytical method for dissolved oxygen based on the quantification of Mn(III) absorbance in a water sample. After Mn(II) reacts with the oxygen molecules in water, Mn(III) is formed and stabilized by hexa-metaphosphate under acidic conditions. The UV visible absorbance of Mn(III) is proportional to the oxygen concentration in the water sample. Compared to the Winkler method, the proposed method has the same accuracy (R = 0.9992 at 0 – 52 mg dm−3) but requires fewer reagents; furthermore, it does not involve titration. Interferences from nitrite and iodate were not observed. This procedure can be used to accurately and quickly determine the oxygen concentrations in different natural water sources, including seawater.