| 摘要 |
[Problem] To provide a method for measuring the concentration of a dissolved substance in a sample, wherein whether the amount of a reagent added to the sample is proper or not can be determined prior to the measurement. [Solution] Light including visible-region components is caused to pass through a sample liquid to be examined which has been colored by addition of a reagent thereto. The visible-region light among the resultant transmitted light is divided into approximately equal three portions to obtain light components respectively within three regions, i.e., red, green, and blue regions, and a light component for dissolved-substance concentration measurement is selected from the three light components. A colorant whereby the liquid to be examined is colored in a tint whereby the light component for dissolved-substance concentration measurement is permitted to pass without being absorbed is added to a reagent to prepare a colorant-containing reagent. On the basis of the transmitted light which has passed through the liquid to be examined to which the colorant-containing reagent has been added, the absorbance of the light component for dissolved-substance concentration measurement and the absorbance A3 of the light component in another region which is attributable to the colorant only are calculated. Whether the reagent has been added to the sample in a just necessary amount can be determined by comparing the absorbance A3 with a reference absorbance A0. |
