JP5141728B2 - Determination of total phosphorus - Google Patents

Description

  The present invention relates to a method for quantifying total phosphorus, and in particular, quantifies the total phosphorus in test water by decomposing the phosphorus compound contained in the test water and converting it into phosphate ions and then quantifying the phosphate ions in the test water. Regarding the method.

  Phosphorus is one of the causative substances related to eutrophication such as ocean water, lake water, river water, and groundwater, so there are regulations on the discharge of factory wastewater. Quantification of phosphate ions is required before discharge. Here, factory effluents not only contain phosphorus as phosphate ions, but may also contain phosphorus elements as various phosphorus compounds. Phosphorus compounds are naturally decomposed after being discharged into the environment, which is the source of phosphorus. It becomes. For this reason, factory wastewater and the like may be required to determine not only phosphate ions but also the total amount of phosphate ions including phosphate ions that can be generated from phosphorus compounds, so-called total phosphorus.

  As an official method for quantifying total phosphorus contained in water, molybdenum blue (ascorbic acid reduction) absorptiometry described in Non-Patent Document 1 is known. In this quantitative method, a heteropoly compound produced by reacting phosphate ions contained in water with hexaammonium heptamolybdate and potassium antimonyl tartrate (dipotassium bis [(+)-tartrate] antimony (III)) is produced. Phosphate ions are quantified by measuring the absorbance of the test water colored by molybdenum blue produced by reduction with L (+)-ascorbic acid.

In the determination of total phosphorus by molybdenum blue (ascorbic acid reduction) absorptiometry, first, a predetermined amount of test water is collected, and pretreatment is performed to decompose the phosphorus compounds contained in the test water and convert them into phosphate ions. . In this pretreatment, after adding a potassium peroxodisulfate solution, which is an oxidizing agent of a phosphorus compound, to the test water, the test water is treated in a high-pressure steam sterilizer set at 120 ° C. for 30 minutes to oxidize the phosphorus compound. Decomposes and converts to phosphate ion. Next, a predetermined amount of ammonium molybdate-ascorbic acid mixed solution is added to the pretreated test water, shaken, and then allowed to stand at 20 to 40 ° C. for about 15 minutes. Then, the absorbance at a wavelength of about 880 nm is measured for this solution, and the phosphate ion concentration (mgPO ₄ ³⁻ / L) of the test water is calculated based on a calibration curve prepared in advance from the measured value.

  The pretreatment of the test water in such a total phosphorus quantification method requires the use of a high-pressure steam sterilizer, that is, a pressure-resistant container, which complicates the operation and requires special safety. In addition, potassium peroxodisulfate used as an oxidizing agent needs to be used in an excessive amount because it decomposes the phosphorus compound at the same time as oxidative decomposition under a temperature environment of 120 ° C. and also proceeds with autolysis.

  Therefore, as a pretreatment method that replaces this pretreatment method, Non-Patent Document 2 proposes a method in which potassium peroxodisulfate is added to test water and then treated at 100 ° C. for 60 minutes. However, in this method, a portion of potassium peroxodisulfate remains in the test water, which may inhibit the reduction of the heteropoly compound by L (+)-ascorbic acid, so the ammonium molybdate-ascorbic acid mixture Before adding the solution, the test water is allowed to cool to 20 to 40 ° C. to suppress the oxidative action of potassium peroxodisulfate, or sodium sulfite as a reducing agent is added to the test water in an alkaline state. It is necessary to extinguish potassium disulfate.

  However, when the oxidation of potassium peroxodisulfate is suppressed by allowing the test water to cool, it takes a long time to cool the test water, making it difficult to complete a series of quantitative operations in a short time. In addition, when sodium sulfite is added to extinguish potassium peroxodisulfate, harmful sulfur dioxide gas is generated. Therefore, safety measures are required.

  In addition, as described in Non-Patent Document 1, the above-described method for quantifying total phosphorus is a trace amount range of 1.25 to 25 μg, so that the test water contains a relatively large amount of phosphate ions and phosphorus compounds. If the test water contains silica such as silicon dioxide, silicic acid and silicate, the quantitative results may vary due to the influence of silica and lack reliability. .

Japanese Industrial Standard JIS K 0102, Factory Wastewater Test Method (2008) 46.1.1 and 46.3

2002 Ministry of the Environment contract work result report, water quality analysis method study investigation, pages 5 and 13

  An object of the present invention is to enable the total phosphorus of test water to be quantified safely and in a short time.

  The present invention relates to a method for quantifying the total phosphorus of test water by decomposing the phosphorus compound contained in the test water and converting it into phosphate ions, and then quantifying the phosphate ions of the test water, In this quantification method, the alkali metal salt of peroxodisulfuric acid or ammonium peroxodisulfate and sulfuric acid were added to the test water, and the process was heated for a predetermined time at a temperature from 65 ° C. to the boiling temperature of the test water. For test water, at least one first compound selected from a hydroxyl group-containing compound group consisting of hydroxycarboxylic acids and alditol, carbon 5 aldose, carbon 6 aldose, carbon 6 ketose and carbon by decomposition Is it a saccharide compound group consisting of monosaccharide-producing compounds capable of producing aldoses of number 5, aldoses of carbon number 6 or ketoses of carbon number 6? Step 2 of adding a first aqueous solution containing at least one of the selected second compounds and subsequently heating for a predetermined time; and hexammonium heptamolybdate or an alkali metal salt of molybdic acid in the test water passed through Step 2 And adding a second aqueous solution containing an antimony compound having an antimony valence of 3, and maintaining the temperature at 65 ° C. or higher, and the test water having undergone step 3, the absorbance at an arbitrary wavelength in the range of 600 to 950 nm And measuring step 4.

  Here, when the first aqueous solution includes only one of the first compound and the second compound, the second aqueous solution further includes a compound that is not included in the first aqueous solution among the first compound and the second compound. . For example, when the first aqueous solution contains only the first compound of the first compound and the second compound, the second aqueous solution contains the second compound. When the first aqueous solution contains only the second compound of the first compound and the second compound, the second aqueous solution contains the first compound.

  In the present invention according to another aspect, the phosphorous compound contained in the test water is decomposed and converted into phosphate ions, and then the total phosphorus contained in the test water is determined by quantifying the phosphate ions in the test water. A method 1 for treating test water, comprising adding an alkali metal salt of peroxodisulfuric acid or ammonium peroxodisulfate and sulfuric acid to test water and heating at a temperature from 65 ° C. to the boiling temperature of the test water for a predetermined time 1 And at least one first compound selected from a hydroxyl group-containing compound group consisting of hydroxycarboxylic acids and alditol, and aldose having 5 carbon atoms, aldose having 6 carbon atoms, and 6 carbon atoms. Saccharification comprising monosaccharide-forming compounds capable of producing aldoses having 5 carbon atoms, aldoses having 6 carbon atoms or ketoses having 6 carbon atoms by ketose and decomposition Subsequently adding a first aqueous solution containing at least one compound of the second compound selected from the object group and a step 2 of heating a predetermined time.

  According to another aspect of the present invention, an alkali metal salt of peroxodisulfuric acid or ammonium peroxodisulfate and sulfuric acid are added to test water containing a phosphorus compound, and the test water is heated to a temperature from 65 ° C. to the boiling temperature of the test water. The present invention relates to a reagent used for quantifying the total phosphorus of test water prepared by heating for a predetermined time in which a phosphorus compound is converted into a phosphate ion. This reagent is composed of hydroxycarboxylic acids and alditol. At least one first compound selected from the group of hydroxyl group-containing compounds, and aldose having 5 carbon atoms, aldose having 6 carbon atoms, ketose having 6 carbon atoms and aldose having 5 carbon atoms by decomposition, aldose having 6 carbon atoms, or A second compound selected from the group of saccharide compounds consisting of monosaccharide-producing compounds capable of producing a ketose having 6 carbon atoms A second aqueous solution containing a first aqueous solution containing at least one of the compounds, an alkali metal salt of hexaammonium heptamolybdate or molybdic acid prepared separately from the first aqueous solution, and an antimony compound having an antimony valence of 3. It consists of an aqueous solution. Here, when the first aqueous solution includes only one of the first compound and the second compound, the second aqueous solution further includes a compound that is not included in the first aqueous solution among the first compound and the second compound. .

  Hydroxycarboxylic acids used in the total phosphorus determination method, the test water treatment method for total phosphorus determination, and the total phosphorus determination reagent according to the present invention include, for example, citric acid, malic acid, aldaric acid, and aldonic acid. . The monosaccharide-generating compound is, for example, an oligosaccharide selected from the group consisting of sucrose, maltose, lactose, raffinose, kestose, stachyose, isomaltulose, maltulose and lactulose.

  Since the total phosphorus quantification method according to the present invention includes the above-described steps 1 to 4, the total phosphorus of the test water can be quantified safely in a short time.

  Moreover, since the processing method of the test water for the determination of total phosphorus according to the present invention includes the above-described steps 1 and 2, the phosphorus compound contained in the test water can be safely converted into phosphate ions, Moreover, the test water after a process can be rapidly applied to the determination process of a phosphate ion.

  Furthermore, since the total phosphorus determination reagent according to the present invention comprises the first aqueous solution and the second aqueous solution described above, it can be used in the total phosphorus determination method according to the present invention.

FIG. 3 is a diagram showing a calibration curve created in Example 1. FIG. 6 is a diagram showing a calibration curve created in Example 2. FIG. 6 is a diagram showing a calibration curve created in Example 3. The figure which shows the calibration curve created in Example 4. FIG. FIG. 6 is a diagram showing a calibration curve created in Example 5. FIG. 6 is a diagram showing a calibration curve created in Example 6. FIG. 10 is a diagram showing a calibration curve created in Example 7. FIG. 10 is a diagram showing a calibration curve created in Example 8. FIG. 10 shows a calibration curve created in Example 9. FIG. 10 is a diagram showing a calibration curve created in Example 10. FIG. 10 is a diagram showing a calibration curve created in Example 11. The figure which shows the calibration curve created in Example 12. The figure which shows the calibration curve created in Example 13.

  The test water capable of quantifying total phosphorus by the quantification method of the present invention is not particularly limited, but in addition to wastewater that is usually provided with phosphorus discharge regulations such as factory wastewater and domestic wastewater, marine water, Natural water such as lake water, river water and groundwater.

  When quantifying the total phosphorus of the test water, a predetermined amount of the test water is collected, and a pretreatment is performed to convert the phosphorus compound contained in the test water into phosphate ions. In this pretreatment, first, an alkali metal salt of peroxodisulfuric acid or ammonium peroxodisulfate (hereinafter sometimes referred to as a peroxodisulfuric acid compound) and sulfuric acid are added to test water, and boiling of the test water starts at 65 ° C. under normal pressure. It is heated for a predetermined time at a temperature up to the temperature, preferably from 75 ° C. to the boiling temperature of the inspection water (step 1). As a result, organic and inorganic phosphorus compounds, particularly organic phosphorus compounds, contained in the test water are oxidatively decomposed by the peroxodisulfuric acid compound, and phosphorus elements are converted into phosphate ions.

  The alkali metal salt of peroxodisulfuric acid used here is usually potassium peroxodisulfate or sodium peroxodisulfate.

  The peroxodisulfuric acid compound is usually added to test water as an aqueous solution dissolved in purified water, for example, pure water, distilled water or ion exchange water. The concentration of the aqueous solution is usually preferably set to 0.4 to 50 g / L, and more preferably set to 3.0 to 40 g / L. The amount of the peroxodisulfuric acid compound aqueous solution added to the test water is preferably set so that the concentration of the peroxodisulfate compound in the test water can sufficiently oxidatively decompose the phosphorus compound contained in the test water. If it is added, the peroxodisulfuric acid compound remains in the inspection water, and there is a possibility of causing false color development in Step 3 described later. For this reason, it is preferable to set the concentration of the peroxodisulfuric acid compound in the test water so that the concentration when the aqueous peroxodisulfate compound solution and sulfuric acid are added to the test water is usually 0.5 to 9 g / L. 1 to 6 g / L is more preferable.

  On the other hand, the amount of sulfuric acid added to the inspection water is preferably set so that the concentration of sulfuric acid when the aqueous peroxodisulfuric acid compound solution and sulfuric acid are added to the inspection water is 0.1 M or more. However, if too much is added, neutralization treatment of excess sulfuric acid may be necessary for the purpose of generating molybdenum blue (coloration of phosphate ions) in Step 2 and later described below. It is preferable to set to 0.1 to 0.3M.

  The heating time of the inspection water in this step varies depending on the heating temperature, but is usually preferably set to 20 to 40 minutes.

  Next, the 1st aqueous solution containing a predetermined compound is added to the test water which passed through the process 1, and it heats for a predetermined time continuously (process 2). This process can be applied to the test water in the high temperature state or the heating continuation state after completion of the process 1 without cooling the test water that has passed through the process 1 by standing cooling or the like.

  The first aqueous solution is obtained by dissolving one or both of at least one first compound selected from the hydroxyl group-containing compound group and a second compound selected from the saccharide compound group in purified water. The first compound is to suppress the consumption of phosphate ions by the silica contained in the test water from forming complexes with phosphate ions, thereby affecting the absorbance measured in step 4 to be described later. is there. That is, the first compound is for suppressing silica from forming a complex with a phosphate ion. In addition, the second compound prevents the peroxodisulfuric acid compound that is not consumed for the oxidative decomposition of the phosphorus compound and remains in the test water from interfering with the reduction of the heteropoly compound produced in Step 3 to be described later. Therefore, the peroxo diacid compound is made to disappear by decomposing.

The hydroxyl group-containing compound group is composed of hydroxycarboxylic acids and alditol. Hydroxycarboxylic acids include, for example, citric acid, malic acid, aldaric acid and aldonic acid, and salts thereof (eg, alkali metal salts). Aldaric used _herein, HO 2 C- (CHOH) formula n-CO ₂ H (n represents an integer of 1 or more, preferably is an integer of from 1 to 5) it was in a water-soluble compound represented by the Examples thereof include tartaric acid having n of 2 and mucoic acid having n of 4. Table Further, aldonic acids used _herein, HO 2 C- (CHOH) formula _n-CH 2 OH (n is an integer of 1 or more, preferably an integer of 1 to 5, more preferably 4 or 5) in For example, n is 1 glyceric acid, n is 4 gluconic acid, and n is 5 glucoheptonic acid. The alditol used here is a compound represented by the general formula of HOH ₂ C— (CHOH) n—CH ₂ OH (n is an integer of 1 or more, preferably an integer of 2 to 5) and is water-soluble. Examples thereof include erythritol, where n is 2, xylitol where n is 3, sorbitol where n is 4, and boremitol where n is 5.

  The saccharide compound group includes a aldose having 5 carbon atoms, an aldose having 6 carbon atoms, a ketose having 6 carbon atoms, and a aldose having 5 carbon atoms, an aldose having 6 carbon atoms, or a ketose having 6 carbon atoms by decomposition. It consists of Examples of aldoses having 5 carbon atoms include ribose, arabinose and xylose. Examples of aldoses having 6 carbon atoms include altrose, glucose, mannose and galactose. Examples of ketoses having 6 carbon atoms include fructose and sorbose.

  As the monosaccharide-generating compound, an oligosaccharide or a glycoside capable of generating an aldose having 5 carbon atoms, an aldose having 6 carbon atoms, or a ketose having 6 carbon atoms by decomposition is used. Examples of oligosaccharides include disaccharides sucrose, maltose, lactose, isomaltulose, maltulose, lactulose, galactosucrose, primeverose and vicyanose, trisaccharides raffinose, kestose, gentianose, planteose and umbelliferose, tetrasaccharides Mention may be made of stachyose and pentasaccharide Belvas course. These exemplary oligosaccharides, upon decomposition, produce xylose (5 carbon aldose), glucose (6 carbon aldose), galactose (6 carbon aldose) or fructose (6 carbon ketose). Can do. Examples of glycosides include arbutin and salicin. These exemplary glycosides can produce glucose upon degradation.

As the first aqueous solution, one of the following three types is used depending on the content of the first compound and the second compound.
Type A: Contains only the first compound.
Type B: Contains only the second compound.
Type C: One containing both the first compound and the second compound.

  When the first aqueous solution of type A or type C is used, the concentration of the first compound in the test water when the first aqueous solution is added in this step is such that the silica contained in the test water forms a complex with phosphate ions. It is preferable to set it to a sufficient amount necessary for suppressing the above. From this point of view, the concentration of the first compound in the test water (concentration at the time of addition) is usually preferably set to 0.5 to 10 g / L, and more preferably set to 1 to 7 g / L. The concentration of the first compound in the first aqueous solution of type A or type C and the amount of the first aqueous solution added to the test water are preferably adjusted based on this viewpoint.

  On the other hand, when the first aqueous solution of type B or type C is used, the concentration of the second compound in the test water when the first aqueous solution is added in this step (in the case where a monosaccharide-generating compound is used, carbon generated by decomposition thereof) The concentration of the aldose of number 5, the aldose of carbon number 6 or the ketose of carbon number 6) is at least an amount necessary for extinguishing the peroxodisulfate compound remaining in the test water, or in excess of the amount. Set to be In the latter case, the second compound added to the test water in this step can also be used as a reducing agent for the heteropoly compound produced in step 3 described later. From this viewpoint, the concentration of the second compound in the test water (concentration at the time of addition) is usually preferably set to 2 to 60 g / L, and more preferably set to 5 to 40 g / L. The concentration of the second compound in the type B or type C first aqueous solution and the amount of the first aqueous solution added to the test water are preferably adjusted based on these viewpoints.

  The heating temperature of the inspection water in this step can be usually set in the same temperature range as the heating in the step 1, but it is usually preferable to set the heating temperature in the step 1 to be the same. Moreover, although the heating time of the test water in this process changes with heating temperature, it is preferable to set normally several seconds-30 minutes.

  In this step, when the first aqueous solution of type A or type C is used, the first compound contained in the added first aqueous solution suppresses the silica contained in the test water from forming a complex with phosphate ions. Is done.

  In this step, when the first aqueous solution of type B or type C is used, the second compound contained in the added first aqueous solution remains in the inspection water without being consumed for the oxidative decomposition of the phosphorus compound. The peroxodisulfuric acid compound is decomposed and disappears. More specifically, when the second compound is an aldose having 5 carbon atoms, an aldose having 6 carbon atoms, or a ketose having 6 carbon atoms, these monosaccharides are not consumed for the oxidative decomposition of the phosphorus compound, but are used in the test water. The peroxodisulfuric acid compound remaining in is decomposed and disappears. On the other hand, when the second compound is a monosaccharide-generating compound, a peroxodisulfuric acid compound remaining by aldose having 5 carbons, aldose having 6 carbons, or ketose having 6 carbons produced by decomposition of the monosaccharide-generating compound is obtained. Decomposes and disappears. When the monosaccharide-generating compound is an oligosaccharide, the remaining peroxodisulfate compound can be decomposed by the oligosaccharide itself.

  The treatment of the inspection water including the above steps 1 and 2 can be operated under normal pressure and can be safely performed because no harmful gas is generated. In addition, since it is not necessary to cool the inspection water by allowing it to cool when the process 1 is shifted from the process 1 to the process 2, the test water after the completion of the process 1 can be transferred to the process 2 smoothly and quickly. It can be completed in a short time.

  Next, a second aqueous solution containing a predetermined compound is added to the test water after the above-described treatment, that is, the test water that has undergone step 2, and the temperature is maintained at 65 ° C. or higher (step 3). The second aqueous solution used here contains at least a molybdenum compound and an antimony compound, and is prepared separately from the first aqueous solution.

  The molybdenum compound used here is hexaammonium heptamolybdate or an alkali metal salt, alkaline earth metal salt or heavy metal salt of molybdic acid. Of these, it is preferable to use hexaammonium heptamolybdate or an alkali metal salt of molybdic acid. Examples of alkali metal salts of molybdate include sodium molybdate, potassium molybdate and lithium molybdate. Examples of alkaline earth metal salts of molybdate include calcium molybdate and magnesium molybdate. Examples of the heavy metal salt of molybdate include zinc molybdate and aluminum molybdate.

  The antimony compound used here is an antimony compound having an antimony valence of 3. Examples of the antimony compound having an antimony valence of 3 include potassium antimonyl tartrate, antimony trioxide (that is, antimony (III) oxide), and a halide salt of antimony. As the halide salt of antimony, it is preferable to use antimony trichloride (that is, antimony (III) chloride) that hardly generates harmful substances by hydrolysis.

  An antimony compound having an antimony valence of 5 can also be used as the antimony compound. Since this antimony compound is naturally converted into an antimony compound having an antimony valence of 3 in an aqueous solution, it can be used as a source of the antimony compound having an antimony valence of 3. Examples of the antimony compound having an antimony valence of 5 usable here include antimony pentoxide (that is, antimony (V) oxide) and an antimony halide salt having a valence of 5. As the halide salt of antimony having a valence of 5, it is preferable to use antimony pentachloride (that is, antimony chloride (V)) that does not easily generate harmful substances by hydrolysis.

The second aqueous solution includes the following types.
Type a: Including the aforementioned second compound as an essential component in addition to the molybdenum compound and antimony compound described above.
Type b: In addition to the above-described molybdenum compound and antimony compound, the above-mentioned first compound as an essential component.
Type c: Contains only the above-mentioned molybdenum compound and antimony compound.

  The type of the second aqueous solution is selected according to the type of the first aqueous solution. That is, when the first aqueous solution is type A, the type a as the second aqueous solution is used. In this case, the second aqueous solution of type a may contain the first compound at the same time. When the first aqueous solution is type B, the type b is used as the second aqueous solution. In this case, the second aqueous solution of type b may contain the second compound at the same time. Furthermore, when the first aqueous solution is type C, any one of type a, type b, and type c may be used as the second aqueous solution. In this case, the thing of the kind a may contain the 1st compound simultaneously, and the thing of the kind b may contain the 2nd compound simultaneously.

  The second aqueous solution can be prepared by dissolving at least one of the molybdenum compound, the antimony compound, and, if necessary, the first compound and the second compound in purified water. Here, when an alkaline earth metal salt of molybdic acid is used as the molybdenum compound, an appropriate amount of sulfuric acid or hydrochloric acid can be added to promote dissolution of the alkaline earth metal salt of molybdic acid. When antimony trioxide is used as the antimony compound, an appropriate amount of hydrochloric acid can be added in order to promote dissolution of antimony trioxide.

  In this step, the concentration of the molybdenum compound in the inspection water when adding the second aqueous solution (concentration converted excluding water molecules when using a hydrate) is usually 0.3 to 3.0 g / L. It is preferable to set, and it is more preferable to set to 0.5 to 2.0 g / L. In addition, the concentration of the antimony compound in the test water at the same time (concentration converted excluding water molecules when a hydrate is used) is usually preferably set to 0.01 to 0.24 g / L. It is more preferable to set it to 0.02 to 0.13 g / L. However, in the test water, the concentration ratio (A: B) between the antimony compound (A) and the molybdenum compound (B) is preferably set to 1: 8 to 100, and preferably 1:10 to 50. It is more preferable to set.

  Furthermore, when the first aqueous solution of type A is used in step 2 and the second aqueous solution of type a is used in this step, the concentration of the second compound in the test water when the second aqueous solution is added (monosaccharide-generating compound) Is used, the concentration of the aldose having 5 carbon atoms, the aldose having 6 carbon atoms or the ketose having 6 carbon atoms produced by the decomposition is at least sufficient to eliminate the peroxodisulfate compound remaining in the test water. It is set to an amount sufficient to reduce the heteropoly compound described later produced in this step. From this point of view, the concentration of the second compound in the test water when the second aqueous solution is added is usually preferably set to 2 to 60 g / L, and more preferably set to 5 to 40 g / L. On the other hand, when the first aqueous solution of type B is used in step 2 and the second aqueous solution of type b is used in this step, the concentration of the first compound in the inspection water when the second aqueous solution is added is It is preferable to set so that the amount of silica contained is sufficient to suppress the formation of complexes with phosphate ions. From this viewpoint, the concentration of the first compound in the test water when the second aqueous solution is added is usually preferably set to 0.5 to 10 g / L, and more preferably set to 1 to 7 g / L. .

  The concentration of each component in the second aqueous solution and the amount of the second aqueous solution added to the test water are adjusted so that the concentration of each component is set as described above when the second aqueous solution is added to the test water. preferable.

  In this step, the second aqueous solution can be added to the inspection water while continuing the heating in step 2. Thereby, the inspection water to which the second aqueous solution is added is maintained at 65 ° C. or higher. The time for maintaining the inspection water at the same temperature or higher is usually set to 3 to 60 minutes. When the heating temperature of the inspection water in step 2 is set to a temperature sufficiently higher than 65 ° C., the heating is stopped at the time of transition from step 2 to step 3 or after the transition to step 3, and the inspection water In this step, the temperature of the inspection water can be maintained at 65 ° C. or higher for a predetermined time while naturally cooling.

  In this process, the phosphate ion originally contained in the test water and the phosphate ion generated by the oxidative decomposition of the phosphorus compound in Step 1 react with the molybdenum compound and antimony compound in the second aqueous solution to form a heteropoly compound. To do. And the produced | generated heteropoly compound is decomposed | disassembled by the decomposition | disassembly product of the 2nd compound of the 1st aqueous solution added at the process 2 or the 2nd aqueous solution added at the process 3 in the acidic environment by the sulfuric acid added at the process 1 or the 2nd compound. Reduced. Specifically, when the second compound is an aldose having 5 carbon atoms, an aldose having 6 carbon atoms, or a ketose having 6 carbon atoms, the heteropoly compound is reduced thereby. Further, when the second compound is a monosaccharide-generating compound, the heteropoly compound is reduced by an aldose having 5 carbon atoms, an aldose having 6 carbon atoms, or a ketose having 6 carbon atoms generated by decomposition thereof. In this case, when the monosaccharide-producing compound is a reducing oligosaccharide, such as maltose, lactose, isomaltulose, maltulose, lactulose, and primeverose, the heteropoly compound produced by the reducing oligosaccharide itself is reduced. obtain. Reduction of such a heteropoly compound generates molybdenum blue (coloration of phosphate ions), and the molybdenum blue changes the color of the inspection water.

  Next, the absorbance at an arbitrary wavelength in the range of 600 to 950 nm is measured for the test water discolored by molybdenum blue (step 4). Then, based on a calibration curve prepared by examining the relationship between the absorbance and the phosphate ion concentration in advance, the phosphate ion amount of the test water, that is, the total phosphorus amount is determined from the absorbance measurement value.

  In this step, since the silica contained in the test water is suppressed from forming a complex with phosphate ions by the first compound added in step 2 or step 3, the measurement accuracy of absorbance can be increased. A highly reliable quantitative result of total phosphorus can be obtained.

  The method for quantifying total phosphorus according to the present invention can be safely carried out without using a special reaction apparatus such as a pressure vessel that requires attention in handling, and it is not necessary to cool inspection water between processes. Therefore, a series of processes can be smoothly advanced without interruption, and can be completed in a short time. For this reason, this quantification method is easy to apply to automation.

  In the method for determining total phosphorus according to the present invention, when a calibration curve is prepared, the linear relationship between the phosphate ion concentration and the absorbance at an arbitrary wavelength in the range of 600 to 950 nm is relatively high. Since it is well established up to the range of the phosphate ion concentration, the upper limit of quantification of phosphate ions contained in the test water is expanded to a range of 4 mg [P] / L or more. Therefore, this quantification method can also be applied to test water having a high content of phosphate ions and phosphorus compounds.

The unit of mg [P] / L indicates the number of milligrams of phosphorus contained in 1 L of water.
Reagents and spectrophotometers The reagents and spectrophotometers used in the following examples and the like are as follows.
Phosphorus standard solution (for water quality test): Wako Pure Chemical Industries, Ltd. Code 160-19241
Silicon standard solution: Wako Pure Chemical Industries, Ltd. Code 192-06031
1M sulfuric acid (for volumetric analysis): Wako Pure Chemical Industries, Ltd. Code 198-09595
Hydrochloric acid (special grade reagent): Wako Pure Chemical Industries, Ltd. Code 080-01066
Potassium peroxodisulfate (for nitrogen and phosphorus measurement): Wako Pure Chemical Industries, Ltd. Code 169-1189
Ammonium peroxodisulfate (special grade reagent): Wako Pure Chemical Industries, Ltd. Code 012-03285
Hexammonium hexamolybdate tetrahydrate (special reagent grade): Wako Pure Chemical Industries, Ltd. Code 018-06901
Lithium molybdate: Wako first grade code 125-03501 from Wako Pure Chemical Industries, Ltd.
Potassium molybdate: Wako Pure Chemical Industries, Ltd. Code 165-04002
Molybdenum (VI) disodium dihydrate (reagent special grade): Wako Pure Chemical Industries, Ltd. Code 190-02475
Potassium antimony tartrate trihydrate (special grade reagent): Wako Pure Chemical Industries, Ltd. Code 020-12832
Antimony oxide (III) (chemical use): Wako Pure Chemical Industries, Ltd. Code 018-04402
Antimony (III) chloride (reagent special grade): Wako Pure Chemical Industries, Ltd. Code 011-0492
DL-tartaric acid: Wako special grade code 203-00052 from Wako Pure Chemical Industries, Ltd.
Mucus acid: Tokyo Chemical Industry Co., Ltd. Code M0466
Sodium gluconate: Wako Special Code 193-13195 from Wako Pure Chemical Industries, Ltd.
Sodium glucoheptonate dihydrate: Tokyo Chemical Industry Co., Ltd. Code G0214
DL-glyceric acid (40% aqueous solution): Tokyo Chemical Industry Co., Ltd. Code D0602
DL-malic acid: Wako Special Code 139-00565 from Wako Pure Chemical Industries, Ltd.
Citric acid: Wako Special Code 030-05525 from Wako Pure Chemical Industries, Ltd.
meso-erythritol: Wako first class code 056-00242 from Wako Pure Chemical Industries, Ltd.
Xylitol: Wako Special Code 244-00542 from Wako Pure Chemical Industries, Ltd.
Sorbitol: Wako first grade code 194-03752 from Wako Pure Chemical Industries, Ltd.
D-fructose: Wako special grade code 127-02765 of Wako Pure Chemical Industries, Ltd.
D-arabinose: Wako Special Code 013-04572 from Wako Pure Chemical Industries, Ltd.
D-glucose (special reagent grade): Wako Pure Chemical Industries, Ltd. Code 047-100592
Sucrose (special grade reagent): Wako Pure Chemical Industries, Ltd. Code 196-00001
D-Raffinose pentahydrate (reagent special grade): Wako Pure Chemical Industries, Ltd. Code 180-00012
D-maltose monohydrate: Wako special grade code 130-00615 from Wako Pure Chemical Industries, Ltd.
Lactose monohydrate (special grade): Wako Pure Chemical Industries, Ltd. Code 128-00095
D-galactose (reagent special grade): Wako Pure Chemical Industries, Ltd. Code 071-00032
1-kestose (for biochemistry): Wako Pure Chemical Industries, Ltd. Code 112-00433
Stachyose n hydrate: Wako Pure Chemical Industries, Ltd. Code 196-12864
Isomaltulose: Palatinose monohydrate (for biochemistry) from Wako Pure Chemical Industries, Ltd. Code 169-12991
Martulose monohydrate: Tokyo Chemical Industry Co., Ltd. Code M1138
Lactulose (for biochemistry): Wako Pure Chemical Industries, Ltd. Code 126-03732
Adenosine-5′-triphosphate disodium salt trihydrate (for biochemistry): Wako Pure Chemical Industries, Ltd. Code 018-16911
Phenyl disodium phosphate dihydrate: Wako Special Grade Code 044-04262 from Wako Pure Chemical Industries, Ltd.
Sodium diphosphate decahydrate (special grade reagent): Wako Pure Chemical Industries, Ltd. Code 195-03025
Ascorbic acid (special grade reagent): Wako Pure Chemical Industries, Ltd. Code 014-04801
Spectrophotometer: Shimadzu Corporation trade name “UV-1600PC”

Phosphate ion solution The phosphate ion solution used in the following examples and the like is as follows.
Five types of phosphate ion solutions having phosphate ion concentrations of 0, 1.0, 2.0, 3.0, and 4.0 mg [P] / L were prepared. For phosphate ion solutions with a phosphate ion concentration of 0 mg [P] / L, distilled water was used as it was, and for other phosphate ion solutions, the phosphate standard concentration was adjusted by diluting the phosphorus standard solution with distilled water. .

Experimental example 1
The following sample water and oxidizer aqueous solution were prepared. D-glucose used for the preparation of the sample waters 2, 3 and 4 assumes an organic substance as a contaminant.
<Sample water>
Sample water 1:
A phosphate ion solution having a phosphate ion concentration of 5 mg [P] / L.
Sample water 2:
An aqueous solution obtained by dissolving sodium diphosphate decahydrate and D-glucose in distilled water (sodium diphosphate equivalent concentration is 5 mg [P] / L, D-glucose concentration is 40 mg / L).
Sample water 3:
An aqueous solution obtained by dissolving adenosine-5′-triphosphate disodium trihydrate and D-glucose in distilled water (adenosine-5′-triphosphate disodium equivalent concentration is 5 mg [P] / L D-glucose concentration is 40 mg / L).
Sample water 4:
An aqueous solution obtained by dissolving phenyl disodium phosphate dihydrate and D-glucose in distilled water (phenyl disodium phosphate equivalent concentration is 5 mg [P] / L, D-glucose concentration is 40 mg / L) .

<Oxidizing agent aqueous solution>
Oxidizing agent aqueous solution 1:
A potassium peroxodisulfate aqueous solution having a concentration of 40 g / L (a potassium peroxodisulfate aqueous solution having a concentration described in JIS K 0102 46.1.1 (hereinafter referred to as “JIS method concentration”)).
Oxidizing agent aqueous solution 2:
A potassium peroxodisulfate aqueous solution having a concentration of 20 g / L (a potassium peroxodisulfate aqueous solution having a concentration of 50% of the JIS method concentration).
Oxidizing agent aqueous solution 3:
A potassium peroxodisulfate aqueous solution having a concentration of 8 g / L (a potassium peroxodisulfate aqueous solution having a concentration of 20% of the JIS method concentration).
Oxidizing agent aqueous solution 4:
A potassium peroxodisulfate aqueous solution having a concentration of 4 g / L (a potassium peroxodisulfate aqueous solution having a concentration of 10% of the JIS method concentration).
Oxidizing agent aqueous solution 5:
A potassium peroxodisulfate aqueous solution having a concentration of 2 g / L (a potassium peroxodisulfate aqueous solution having a concentration of 5% of the JIS method concentration).
Oxidizing agent aqueous solution 6:
A potassium peroxodisulfate aqueous solution having a concentration of 0.4 g / L (a potassium peroxodisulfate aqueous solution having a concentration of 1% of the JIS method concentration).

  1 mL of one of the oxidant aqueous solutions 1 to 6 was added to 5 mL of each of the sample waters 1 to 4, and 1 mL of 1M sulfuric acid was further added, and then each sample water was heated at 95 ° C. for 40 minutes using a block heater. . Each sample water was diluted 5 times with distilled water, and each sample water was colored according to the molybdenum blue (ascorbic acid reduction) spectrophotometric method described in 46.1.1 of JIS K 0102, and the absorbance at 890 nm was obtained. It was measured. That is, 0.2 mL of a 5: 1 mixed solution of ammonium molybdate solution and ascorbic acid solution specified in the same method was added to diluted sample water and left at 25 ° C. for about 15 minutes, and then the absorbance at 890 nm was measured. It was measured. The results are shown in Table 1.

  In Table 1, the oxidative degradation rate of sample waters 2 to 4 is the ratio of absorbance to the absorbance measured for sample water 1, and is converted into phosphate ions by oxidative degradation among the phosphorous compounds contained in sample water. Shows the percentage of food. According to the oxidative degradation rate in Table 1, the phosphorus compound contained in the sample water is 90% or more when an aqueous solution (oxidant aqueous solution 4) having a potassium peroxodisulfate concentration of 4 g / L or more is used. When an aqueous solution (oxidant aqueous solution 3) having a concentration of 8 g / L or more is used, 95% or more is decomposed and converted into phosphate ions. From this, potassium peroxodisulfate in the oxidizing agent aqueous solution can effectively oxidatively decompose the phosphorus compound contained in the sample water even when the concentration is set to about 1/5 or less of the JIS method concentration. .

Experimental example 2
The following sample water was prepared. D-glucose used for the preparation of the sample waters 5 and 6 is assumed to be an organic substance as a contaminant.
Sample water 5:
Dissolving adenosine-5'-triphosphate disodium trihydrate, phenyl disodium phosphate dihydrate and D-glucose in distilled water to a concentration of 1 mg adenosine-5'-triphosphate. [P] / L, phenyl disodium phosphate concentration adjusted to 1 mg [P] / L, and D-glucose concentration adjusted to 50 mg / L.
Sample water 6:
An aqueous solution in which sodium diphosphate decahydrate and D-glucose are dissolved in distilled water to adjust the sodium diphosphate concentration to 2 mg [P] / L and the D-glucose concentration to 50 mg / L.

  To 5 mL of each sample water, 0.8 mL of a potassium peroxodisulfate aqueous solution having a concentration of 30 g / L and 1.2 mL of 1M sulfuric acid were added. And each sample water was heated for 40 minutes at 95 degreeC using the block heater, Then, it cooled with water rapidly. Distilled water was added to each sample water after cooling to dilute it twice, and in the same manner as in Experimental Example 1, according to molybdenum blue (ascorbic acid reduction) spectrophotometric method described in 46.1.1 of JIS K 0102 Each sample water was colored and the absorbance at 890 nm was measured. Moreover, about the case where the heating time of each sample water by a block heater was shortened, the sample water was similarly developed and the light absorbency of 890 nm was measured. The results are shown in Table 2.

  In Table 2, the relative decomposition rate means the decomposition rate of the phosphorus compound at each heating time when the decomposition rate of the phosphorus compound contained in each sample water is 100% when the heating time is 40 minutes, This is calculated based on the ratio of the absorbance to the absorbance when the heating time is 40 minutes. According to Table 2, it can be seen that the phosphorus compound in the sample water is decomposed by 90% or more in 25 minutes and 98% or more in 30 minutes.

Experimental example 3
The following sample water was prepared.
Sample water 7:
Adenosine-5′-triphosphate disodium trihydrate concentration of 65 mg / L (1 mg [P] / L), phenyl disodium phosphate dihydrate concentration of 82 mg / L (1 mg [P] / L) Adenosine-5′-triphosphate disodium trihydrate in distilled water so that the concentration of D-glucose (assuming organic substances as impurities) is 20 mg / L and the silica concentration is 100 mg [Si] / L Product, disodium phenyl phosphate dihydrate, D-glucose and silicon standard solution were dissolved, and 5 mL of sample water was prepared. This sample water has a total phosphorus concentration of 2 mg [P] / L. In the preparation of the sample water, since the silicon standard solution is alkaline, a silicon standard solution neutralized by adding 1 M sulfuric acid was used, and the silica concentration was adjusted as described above.

Sample water 8:
Without using the silicon standard solution, 5 mL of sample water having a total phosphorus concentration of 2 mg [P] / L was prepared in the same manner as Sample Water 7.

  To sample water 7, 1.4 mL of 1M sulfuric acid and 1.0 mL of potassium peroxodisulfate having a concentration of 30 g / L were added and heated at 95 ° C. for 40 minutes using a block heater. Subsequently, 1.0 mL of a color former was added while the sample water 7 was heated to 95 ° C., and left for 22 minutes. The color former used here is a solution in which sucrose, hexaammonium heptamolybdate tetrahydrate and potassium antimonyl tartrate trihydrate are dissolved in distilled water, and the concentration of sucrose is 100 g / L, hexamolybdate hexahydrate. The concentration of ammonium tetrahydrate was adjusted to 7 g / L, and the concentration of potassium antimonyl tartrate trihydrate was adjusted to 0.5 g / L.

  It was 1.49 when the light absorbency of 830 nm was measured about the sample water 7 after completion | finish of a heating. The absorbance of the same wavelength was measured for the sample water 8 treated in the same manner, and it was 0.99. Since the sample water 7 containing silica has an absorbance about 1.5 times that of the sample water 8 not containing silica, the measurement result of total phosphorus is greatly affected by silica.

Examples 1-13
(Create a calibration curve)
Table 5 shows 1 mL of 1 M sulfuric acid for 5 mL of each of the five types of phosphate ion solutions with phosphate ion concentrations of 0, 1.0, 2.0, 3.0 and 4.0 mg [P] / L The peroxodisulfuric acid compound aqueous solution 0.8mL shown was added, and it heated at 95 degreeC for 30 minute (s) using the block heater.

  Next, the state heated to 95 ° C. was maintained, and 1.0 mL of the first aqueous solution was added and left for 2 minutes. Subsequently, 1.0 mL of the second aqueous solution was further added while maintaining the state heated to 95 ° C., and left for 20 minutes. The first aqueous solution and the second aqueous solution used here were prepared by dissolving the components shown in Table 3 in distilled water so as to have the concentrations shown in the same table.

  For each phosphate ion solution treated as described above, the absorbance at the wavelengths shown in Table 4 was measured, and a calibration curve for determining the phosphate ion concentration from the absorbance was prepared. The results are shown in FIGS. 1 to 13, this calibration curve shows high linearity at least in the range of the phosphate ion concentration of 0 to 4 mg [P] / L.

(Test water preparation)
The following test water was prepared.
Test water A:
Adenosine-5′-triphosphate disodium trihydrate concentration of 32.5 mg / L (0.50 mg [P] / L), phenyl disodium phosphate dihydrate concentration of 41 mg / L (0.50 mg) [P] / L), D-glucose (assuming organic substances as impurities) in distilled water to a concentration of 20 mg / L, adenosine-5′-triphosphate disodium trihydrate, phosphoric acid Dissolve phenyl disodium dihydrate and D-glucose, and prepare 5 mL of test water having a total phosphorus concentration of 1.00 mg [P] / L.

Test water B:
5 mL of test water having a total phosphorus concentration of 1.00 mg [P] / L was prepared in the same manner as test water A, except that the silicon standard solution was further dissolved so that the silica concentration was 60 mg / L. In the preparation of the test water, a silicon standard solution neutralized by adding 1 M sulfuric acid was used because the silicon standard solution was alkaline.

Test water C:
5 mL of test water having a total phosphorus concentration of 1.00 mg [P] / L was prepared in the same manner as test water B, except that the silicon standard solution was dissolved so that the silica concentration was 50 mg / L.

Test water D:
5 mL of test water having a total phosphorus concentration of 1.00 mg [P] / L was prepared in the same manner as test water B, except that the silicon standard solution was dissolved so that the silica concentration was 80 mg / L.

Test water E:
Adenosine-5′-triphosphate disodium trihydrate concentration is 65 mg / L (1.00 mg [P] / L), phenyl disodium phosphate dihydrate concentration is 82 mg / L (1.00 mg [P ] / L), D-glucose (assuming organic matter as a contaminant) in distilled water to a concentration of 20 mg / L, adenosine-5'-disodium triphosphate trihydrate, phenyl diphosphate Sodium dihydrate and D-glucose were dissolved, and 5 mL of test water having a total phosphorus concentration of 2.00 mg [P] / L was prepared.

Test water F:
5 mL of test water having a total phosphorus concentration of 2.00 mg [P] / L was prepared in the same manner as test water E, except that the silicon standard solution was further dissolved so that the silica concentration was 90 mg / L. In the preparation of the test water, a silicon standard solution neutralized by adding 1 M sulfuric acid was used because the silicon standard solution was alkaline.

Test water G:
5 mL of test water having a total phosphorus concentration of 2.00 mg [P] / L was prepared in the same manner as test water F, except that the silicon standard solution was further dissolved so that the silica concentration was 100 mg / L.

Test water H:
5 mL of test water having a total phosphorus concentration of 2.00 mg [P] / L was prepared in the same manner as test water F, except that the silicon standard solution was further dissolved so that the silica concentration was 70 mg / L.

Test water I:
5 mL of test water having a total phosphorus concentration of 2.00 mg [P] / L was prepared in the same manner as test water F, except that the silicon standard solution was further dissolved so that the silica concentration was 60 mg / L.

Test water J:
Adenosine-5′-triphosphate disodium trihydrate concentration of 97.5 mg / L (1.50 mg [P] / L), phenyl disodium phosphate dihydrate concentration of 123 mg / L (1.50 mg) [P] / L), D-glucose (assuming organic substances as impurities) in distilled water to a concentration of 20 mg / L, adenosine-5′-triphosphate disodium trihydrate, phosphoric acid Dissolve phenyl disodium dihydrate and D-glucose, and prepare 5 mL of test water having a total phosphorus concentration of 3.00 mg [P] / L.

Test water K:
5 mL of test water having a total phosphorus concentration of 3.00 mg [P] / L was prepared in the same manner as test water J except that the silicon standard solution was further dissolved so that the silica concentration was 70 mg / L. In the preparation of the test water, a silicon standard solution neutralized by adding 1 M sulfuric acid was used because the silicon standard solution was alkaline.

Test water L:
5 mL of test water having a total phosphorus concentration of 3.00 mg [P] / L was prepared in the same manner as test water K, except that the silicon standard solution was further dissolved so that the silica concentration was 60 mg / L.

Test water M:
5 mL of test water having a total phosphorus concentration of 3.00 mg [P] / L was prepared in the same manner as test water K, except that the silicon standard solution was further dissolved so that the silica concentration was 50 mg / L.

Test water N:
Adenosine-5′-triphosphate disodium trihydrate concentration is 130 mg / L (2.00 mg [P] / L), phenyl disodium phosphate dihydrate concentration is 164 mg / L (2.00 mg [P ] / L), D-glucose (assuming organic matter as a contaminant) in distilled water to a concentration of 20 mg / L, adenosine-5'-disodium triphosphate trihydrate, phenyl diphosphate Sodium dihydrate and D-glucose were dissolved, and 5 mL of test water having a total phosphorus concentration of 4.00 mg [P] / L was prepared.

Test water O:
5 mL of test water having a total phosphorus concentration of 4.00 mg [P] / L was prepared in the same manner as test water N, except that the silicon standard solution was further dissolved so that the silica concentration was 80 mg / L. In the preparation of the test water, a silicon standard solution neutralized by adding 1 M sulfuric acid was used because the silicon standard solution was alkaline.

Test water P:
5 mL of test water having a total phosphorus concentration of 4.00 mg [P] / L was prepared in the same manner as test water O except that the silicon standard solution was further dissolved so that the silica concentration was 90 mg / L.

(Total phosphorus determination of test water)
To the test water shown in Table 4, 1.2 mL of 1M sulfuric acid and 0.8 mL of a peroxodisulfuric acid compound aqueous solution shown in Table 3 were added and heated at 95 ° C. for 30 minutes using a block heater. Next, with the test water heated to 95 ° C., 1.0 mL of the first aqueous solution (the same as that used when preparing the calibration curve) was added and left for 2 minutes. Further, 1.0 mL of the second aqueous solution (the same as that used when preparing the calibration curve) was added while the test water was heated to 95 ° C., and heating at the same temperature was continued for 20 minutes.

  About the test water after completion | finish of a heating, the light absorbency of the wavelength shown in Table 4 was measured, and the total phosphorus density | concentration was quantified based on the analytical curve created from the measured value. The results are shown in Table 4.

Claims (8)

A method for quantifying the total phosphorus of the test water by decomposing the phosphorus compound contained in the test water and converting it into phosphate ions, and then quantifying the phosphate ion of the test water,
Adding an alkali metal salt of peroxodisulfuric acid or ammonium peroxodisulfate and sulfuric acid to the test water, and heating at a temperature from 65 ° C. to the boiling temperature of the test water for a predetermined time;
At least one first compound selected from a hydroxyl group-containing compound group consisting of hydroxycarboxylic acids and alditol, and aldose having 5 carbon atoms, aldose having 6 carbon atoms, and 6 carbon atoms with respect to the test water having undergone step 1 Including at least one compound selected from the group consisting of saccharide compounds consisting of ketose and saccharides capable of producing aldoses having 5 carbon atoms, aldoses having 6 carbon atoms or ketoses having 6 carbon atoms by decomposition. Step 2 of adding the first aqueous solution and subsequently heating for a predetermined time;
Adding a second aqueous solution containing an hexamonammonium hexamolybdate or an alkali metal salt of molybdic acid and an antimony compound having an antimony valence of 3 to the test water after step 2, and maintaining the temperature at 65 ° C. or higher;
Measuring the absorbance of any wavelength in the range of 600 to 950 nm for the test water that has undergone step 3, and
When the first aqueous solution includes only one of the first compound and the second compound, the second aqueous solution is not included in the first aqueous solution of the first compound and the second compound. Further comprising a compound,
Quantitative method for total phosphorus.   The hydroxycarboxylic acids include citric acid, malic acid, aldaric acid and aldonic acid, and the monosaccharide-forming compound is selected from the group consisting of sucrose, maltose, lactose, raffinose, kestose, stachyose, isomaltulose, maltulose and lactulose. The method for quantifying total phosphorus according to claim 1, which is a selected oligosaccharide.   The total phosphorous according to claim 1 or 2, wherein the first aqueous solution contains only the first compound of the first compound and the second compound, and the second aqueous solution contains the second compound. Quantitation method.   3. The total phosphorous according to claim 1, wherein the first aqueous solution contains only the second compound of the first compound and the second compound, and the second aqueous solution contains the first compound. Quantitation method. Treatment of the test water when the total phosphorus contained in the test water is quantified by decomposing the phosphorous compound contained in the test water and converting it into phosphate ions, and then quantifying the phosphate ion of the test water A method,
Adding an alkali metal salt of peroxodisulfuric acid or ammonium peroxodisulfate and sulfuric acid to the test water, and heating at a temperature from 65 ° C. to the boiling temperature of the test water for a predetermined time;
At least one first compound selected from a hydroxyl group-containing compound group consisting of hydroxycarboxylic acids and alditol, and aldose having 5 carbon atoms, aldose having 6 carbon atoms, and 6 carbon atoms with respect to the test water having undergone step 1 Including at least one compound selected from the group consisting of saccharide compounds consisting of ketose and saccharides capable of producing aldoses having 5 carbon atoms, aldoses having 6 carbon atoms or ketoses having 6 carbon atoms by decomposition. Step 2 of adding the first aqueous solution and subsequently heating for a predetermined time;
Of test water for the determination of total phosphorus, including   The hydroxycarboxylic acids include citric acid, malic acid, aldaric acid and aldonic acid, and the monosaccharide-producing compound is selected from the group consisting of sucrose, maltose, lactose, raffinose, kestose, stachyose, isomaltulose, maltulose and lactulose. The method for treating test water for quantifying total phosphorus according to claim 5, which is a selected oligosaccharide. Prepared by adding an alkali metal salt of peroxodisulfuric acid or ammonium peroxodisulfate and sulfuric acid to test water containing a phosphorus compound, and heating at a temperature from 65 ° C. to the boiling temperature of the test water for a predetermined time, A reagent used for quantifying the total phosphorus of the test water for measurement in which the phosphorus compound is converted into phosphate ions,
At least one first compound selected from the group of hydroxyl group-containing compounds consisting of hydroxycarboxylic acids and alditols, and aldoses having 5 carbon atoms, aldoses having 6 carbon atoms, ketoses having 6 carbon atoms and aldoses having 5 carbon atoms by decomposition; A first aqueous solution containing at least one compound selected from the group of saccharide compounds consisting of a saccharide compound group consisting of a monosaccharide generating compound capable of generating a C6 aldose or a C6 ketose;
A second aqueous solution containing an antimony compound having an antimony valence of 3 and an alkali metal salt of hexaammonium heptamolybdate or molybdic acid prepared separately from the first aqueous solution,
When the first aqueous solution includes only one of the first compound and the second compound, the second aqueous solution is not included in the first aqueous solution of the first compound and the second compound. Further comprising a compound,
Reagent for determination of total phosphorus.   The hydroxycarboxylic acids include citric acid, malic acid, aldaric acid and aldonic acid, and the monosaccharide-producing compound is selected from the group consisting of sucrose, maltose, lactose, raffinose, kestose, stachyose, isomaltulose, maltulose and lactulose. The reagent for quantifying total phosphorus according to claim 7, which is a selected oligosaccharide.

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