| 摘要 |
<P>PROBLEM TO BE SOLVED: To attain a quantitative method by which phosphate ions with comparatively high concentration contained in inspection water is quantitated and which is suitable for automation. <P>SOLUTION: A quantitative method of phosphate ions includes: a process 1 of adding a color-producing agent containing sulfuric acid, molybdenum compound of hexaammonium heptamolybdate and one of alkali metal salt of molybdate, antimony compound whose valence of antimony is 3, iron salt capable of generating bivalent or trivalent iron ions and hydroxylamine salt to the inspection water to be heated at temperature from 65°C to boiling temperature of the inspection water; and a process 2 of measuring absorbance of arbitrary wavelength within a range of 600 to 900 nm for the inspection water which passes through the process 1. One embodiment of the color-producing agent to be used here consists of: a first agent consisting of aqueous solution containing sulfuric acid and hydroxylamine salt; and a second agent consisting of aqueous solution containing the molybdenum compound, antimony compound and iron salt, and iron salt capable of generating trivalent iron ion. <P>COPYRIGHT: (C)2012,JPO&INPIT |
