Method for quantification of total phosphorous

Abstract

The purpose is to quantify the total phosphorous in water of interest safely and within a short time. Provided is a method for quantifying the total phosphorus in water of interest by decomposing phosphorous compounds contained in the water to convert the phosphorous compounds into phosphate ions and determining the quantity of the phosphate ions in the water, wherein an alkali metal salt of peroxydisulfuric acid and sulfuric acid are added to the water and the resulting mixture is heated at a temperature ranging from 65°C to a boiling point for a predetermined period. Subsequently, a color-developing agent comprising at least one hydroxy-group-containing compound selected from a group of hydroxy-group-containing compounds consisting of hydroxycarboxylic acids and alditols, a saccharide compound selected from a group of saccharide compounds consisting of aldoses having 5 carbon atoms, aldoses having 6 carbon atoms, ketoses having 6 carbon atoms and monosaccharide-generating compounds capable of being decomposed to generate any one of the aforementioned monosaccharides and hexaammonium heptamolybdate is added to the water, the resulting mixture is heated at 65°C or higher for a predetermined period, and the absorbance of any wavelength ranging from 600 to 950 nm in the water is measured.

Description

technical field [0001] The present invention relates to a method for quantifying total phosphorus, in particular, after decomposing phosphorus compounds contained in test water into phosphate ions, the phosphate ions in the test water are quantified, and the total phosphorus in the test water is thus quantified. Quantitative method. Background technique [0002] Phosphorus is one of the causative substances related to eutrophication of ocean water, lake water, river water, groundwater, etc. Therefore, discharge restrictions are set in factory effluents, etc., and phosphate ion quantification is required before discharge of factory effluents, etc. into the environment. Here, factory effluents and the like contain phosphorus not only as phosphate ions but also as various phosphorus compounds, which become sources of phosphorus by natural decomposition after they are discharged into the environment. Therefore, it is sometimes required to quantify not only phosphate ions but al...

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Problems solved by technology

[0008] In addition, as described in Non-Patent Document 1, the quantification range of the above-mentioned total phosphorus quantification method is a trace range of 1.25 to 25 μg, so it is not applicable to test the presence of a large amount of phosphate ions and phosphorus compounds in the water. In addition, if the test water contains silicon dioxide such as silicon dioxide, silicic acid, and silicate, the quantitative results will fluctuate due to the influence of silicon dioxide, and the reliability will be lacking.

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