bromate ion measurement method and apparatus

Abstract

A method for measuring bromate ion is provided that provides high-sensitivity measurement results more simply and more quickly than conventional bromate ion measurement methods. A fluorescent substance that is quenched by coexistence with bromate ions is added to a sample and the fluorescence intensity of the fluorescent substance after quenching is measured, the measured fluorescence intensity being subtracted from the fluorescence intensity of a standard sample containing no bromate ions to calculated the fluorescence intensity difference. The bromate ion concentration is calculated from the calculated fluorescence intensity difference, using a pre-determined calibration line between the fluorescence intensity difference and the bromate ion concentration.

1 . A method for measuring bromate ions in a sample, comprising the steps of:
 mixing a fluorescent substance with the sample, the fluorescent substance being quenched by coexistence with bromate ions under acidic conditions;   measuring a florescence intensity after quenching of the fluorescent substance;   subtracting the measured fluorescence intensity from a fluorescence intensity of a standard sample that does not contain bromate ions to calculate a fluorescence intensity difference; and   a step of using a pre-determined calibration line between the fluorescence intensity difference and the bromate ion concentration to calculate the bromate ion concentration from the calculated fluorescence intensity difference.   
     
     
         2 . The method according to  claim 1 , wherein the method further comprises a step of adding a chelating agent to the sample before the step of mixing the fluorescent substance and the sample. 
     
     
         3 . The method according to  claim 1 , wherein the fluorescent substance is trifluoroperazine. 
     
     
         4 . The method according to  claim 2 , wherein the chelating agent is ethylene diamine tetraacetate. 
     
     
         5 . The method according to  claim 2 , wherein the fluorescent substance is trifluoroperazine. 
     
     
         6 . The method according to  claim 5 , wherein the chelating agent is ethylene diamine tetraacetate. 
     
     
         7 . An apparatus for measuring the bromate ions in a sample, comprising:
 means for mixing a fluorescent substance with a sample, the fluorescent substance to be quenched by coexistence with bromate ions under oxidizing conditions;   means for measuring a fluorescence intensity after quenching of the fluorescent substance;   means for subtracting the measured fluorescence intensity from a fluorescence intensity of a standard sample that does not contain bromate ions to calculate a fluorescence intensity difference; and   means for using a pre-determined calibration line between the fluorescence intensity difference and the bromate ion concentration to calculate the bromate ion concentration from the calculated fluorescence intensity difference.   
     
     
         8 . The apparatus according to  claim 7 , wherein the apparatus is constituted so as to measure the admixture of the sample and the fluorescent substance that is temporarily held in the mixing means with the fluorescence intensity measuring means. 
     
     
         9 . The apparatus according to  claim 7 , wherein the apparatus is constituted so as to measure with the fluorescence intensity measuring means the admixture of the sample and the fluorescent substance that flows continuously in the mixing means.