Abstract: A method for measuring bromate ions includes: an adding step of adding a fluorescent substance whose fluorescence intensity changes by the coexistence of bromate ions to sample water; a measuring step of measuring the fluorescence intensity of the fluorescent substance; a difference calculating step of calculating a difference between the fluorescence intensity measured and a reference fluorescence intensity of reference sample water that contains no bromate ion; and a concentration calculating step of calculating bromate ion concentration from the calculated fluorescence intensity difference. The measuring step includes a step of measuring the fluorescence intensity at any one of a case where an excitation wavelength is 264 nm and an emission wavelength is 400 nm, a case where the excitation wavelength is 264 nm and the emission wavelength is 480 nm, and a case where the excitation wavelength is 300 nm and the emission wavelength is 400 nm.

Abstract: A method for measuring bromate ions includes: an adding step of adding a fluorescent substance whose fluorescence intensity changes by the coexistence of bromate ions to sample water; a measuring step of measuring the fluorescence intensity of the fluorescent substance; a difference calculating step of calculating a difference between the fluorescence intensity measured and a reference fluorescence intensity of reference sample water that contains no bromate ion; and a concentration calculating step of calculating bromate ion concentration from the calculated fluorescence intensity difference. The measuring step includes a step of measuring the fluorescence intensity at any one of a case where an excitation wavelength is 264 nm and an emission wavelength is 400 nm, a case where the excitation wavelength is 264 nm and the emission wavelength is 480 nm, and a case where the excitation wavelength is 300 nm and the emission wavelength is 400 nm.