KR101340767B1 - the detecting method for low concentration of phosphate - Google Patents

Abstract

The present invention relates to a detection method for analyzing water quality, that is, a method for detecting total phosphorus or phosphate-phosphorus concentration, and more specifically, a phosphate-phosphorous powder detection reagent prepared by mixing Potassium Pyrosulfate, Ascorbic Acid, Molybdate, and tartrate. Phosphate-phosphate (PO ₄ -P, Phosphate), which is encountered with the powder detection reagent of the present invention, meets sodium molybdate in the powder detection reagent and forms an intermediate, a phosphomolybdate compound (Phosphomolybdate complex). ) And also a method for detecting phosphate-phosphate concentration using a process in which the phosphomolybdate complex thus formed meets ascorbic acid to cause a color change. Technology.
The present invention is a process of inducing a color change by reacting by adding a predetermined amount of a detection reagent mixed with a mixture of Potassium Pyrosulfate, Ascorbic Acid, Molybdate, tartrate to a sample containing a low concentration of phosphate-phosphate to be measured, the induced A method of detecting phosphate phosphorus concentrations is provided by comparing the degree of color change against a colorimetric table for standard solutions.
In addition, a process of inducing a color change by adding a predetermined amount of a detection reagent mixed with Potassium Pyrosulfate, Ascorbic Acid, Molybdate, and tartrate to a sample containing a low concentration of phosphate-phosphate to be reacted to induce color change, the induced color change It provides a method for detecting the phosphate phosphorus concentration using the degree of absorbance.
In addition, a process of generating a phosphomolybdate compound, which is an intermediate forming material, meets with sodium molybdate in the detection reagent, and the phosphomolybdate compound may be used ascorbic acid ( It provides a method to detect phosphate concentrations consisting of a process that involves the process of meeting color changes with ascorbic acid).

Description

The detecting method for low concentration of phosphate

The present invention relates to a detection method for analyzing water quality, that is, a method for detecting total phosphorus or phosphate-phosphorus concentration, and more specifically, a phosphate-phosphorous powder detection reagent prepared by mixing Potassium Pyrosulfate, Ascorbic Acid, Molybdate, and tartrate. Phosphate-phosphate (PO ₄ -P, Phosphate), which is encountered with the powder detection reagent of the present invention, meets sodium molybdate in the powder detection reagent and forms an intermediate, a phosphomolybdate compound (Phosphomolybdate complex). ) And also a method for detecting phosphate-phosphate concentration using a process in which the phosphomolybdate complex thus formed meets ascorbic acid to cause a color change. Technology.

Recently, as environmental regulations on pollutants such as nitrogen or phosphorus contained in river water, lake water, and waste water have been tightened, various types of water quality measurements have been made on discharged water or river water. In addition to the basic requirements to ensure precision and reproducibility, the characteristics required for water quality measurement should be fast, convenient, environmentally friendly and economical.

Among the pollutants mentioned above, regulation of total phosphorus, which is an important pollutant that causes eutrophication and green algae of appeals, is regarded as important, and water quality measurement is frequently performed as a preliminary operation to discharge effluent meeting environmental standards.

Phosphorus measurement in water is indicated by total phosphorus and phosphate-phosphorus (PO ₄ ^-3 ), which refers to the total amount of phosphorus compounds, organics and phosphate-phosphates in a sample.

It is very important to measure phosphate-phosphorus because total phosphorus is measured by converting organic matter and phosphorus compound into phosphate-phosphorus form.

In general, the phosphate-phosphorus measurement is measured by the absorbance method through the tin chloride reduction method or ascorbic acid reduction method.

The conventional phosphate-phosphorus measurement method has a disadvantage that the measurement process is very complicated with various reagents and complicated procedures, and that the measurement time is not only economical in terms of cost but also takes a long time due to the use of various reagents.

Therefore, the present invention is intended to solve the above problems.

In addition, it is intended to provide a detection method that can significantly exclude the effects of interference by other kinds of ions that may occur in the measurement of phosphate-phosphorus concentration (especially low concentration measurement).

In addition, the present invention is a test using a solvent extraction method, such as using a separatory funnel, the mixture of sulfuric acid and butyl alcohol to stand and separate the liquid when the coloring material coexist in the prior art or measure the low concentration of phosphate-phosphorus It is intended to provide a detection method that solves the problem to be performed.

Another object of the present invention is to provide a detection method capable of performing a simple measurement that does not require excessive measurement time.

In addition, the present invention is to provide a detection method that can measure the phosphate-phosphorus concentration using the colorimetric control as well as the absorbance method.

In another aspect, the present invention is to provide a detection method that can measure the phosphate-phosphorus concentration does not need to adjust the pH even if the sample is acidic or basic.

In addition, the present invention can measure the low concentration of phosphate-phosphorus, which solves the disadvantage of the cost-effectiveness and the long time-consuming measurement by using a variety of reagents and a complicated procedure and the complexity of the measurement process. It is intended to provide a detection method.

In order to solve the above problems and needs,

A process of inducing color change by adding a predetermined amount of a detection reagent mixed with Potassium Pyrosulfate, Ascorbic Acid, Molybdate, and tartrate to a sample containing a low concentration of phosphate-phosphate to be measured, and inducing the color change. It provides a method for detecting the phosphate phosphorus concentration by comparing the colorimetric table with the standard solution.

In addition, a process of inducing a color change by adding a predetermined amount of a detection reagent mixed with Potassium Pyrosulfate, Ascorbic Acid, Molybdate, and tartrate to a sample containing a low concentration of phosphate-phosphate to be reacted to induce color change, the induced color change It provides a method for detecting the phosphate phosphorus concentration using the degree of absorbance.

In addition, the process of generating a phosphomolybdate compound (Sodium Molybdate) as an intermediate forming the intermediate material (Sodium Molybdate) in the detection reagent, the phosphomolybdate compound (Phosphomolybdate complex) is ascorbic acid ( It provides a method to detect phosphate concentrations consisting of a process that involves the process of meeting color changes with ascorbic acid).

Using a separatory funnel, which may occur when measuring phosphate-phosphorus (especially at the measurement of low concentration of phosphate-phosphorus) using the phosphate-phosphorus concentration detection method of the present invention, by mixing sulfuric acid and butyl alcohol and separating the liquid The effect of solving the problem of having to perform the test by using a solvent extraction method such as

In addition, when the phosphate-phosphorus concentration detection method of the present invention is used, the effect of remarkably eliminating the influence of interference by other kinds of ions that may occur in the measurement appears.

In addition, when the measurement using the phosphate-phosphorus concentration detection method of the present invention does not require excessive measurement time, the effect can be performed very simply.

In addition, when the phosphate-phosphorus concentration is measured using the detection method of the present invention, compared to the existing measurement method has the effect of ensuring the same or more accuracy.

In addition, when the phosphate-phosphorus concentration is measured by using the detection method of the present invention, even if the sample is acidic or basic, the effect of not having to adjust the pH is created.

1 is a standard liquid calibration curve.

Hereinafter, the present invention will be described in detail with reference to the drawings and tables.

In the conventional measurement method of phosphate-phosphorus, the measurement range of the concentration of phosphate-phosphorus can usually be measured in the range of 0.002 to 0.05 mg / l.

The present invention particularly provides a detection method having a very high detection sensitivity in measuring a sample containing a low concentration of phosphate-phosphorus in the above-described measurement range.

In the present invention, the low concentration of phosphate-phosphorus means a range of 0.002 to 0.02 mg / l, and in the range of this concentration, the present invention shows an excellent detection effect.

The present invention provides a detection method that remarkably improves the measuring method using the absorbance method, which is a method for detecting phosphate-phosphorus concentration.

The present invention provides a method for detecting phosphate-phosphorus concentration by using the degree of color development by reacting a phosphate-phosphorus detection reagent to a sample containing phosphate-phosphorus to be measured.

The present invention performs the process of color development through a certain reaction time after adding a certain amount of the phosphate-phosphorous powder detection reagent of the present invention to a predetermined amount of the sample containing phosphate-phosphorus.

The phosphate-phosphorus detection reagent which is a technical feature of the present invention is described.

The powder detection reagent of the present invention refers to a powdered reagent prepared by mixing with Potassium Pyrosulfate, Ascorbic Acid, Molybdate, and tartrate.

In the present invention, Potassium Pyrosulfate contains S ₂ O ₇ ^-2 which is a pyrosulfite anion as the chemical formula K ₂ S ₂ O ₇ . Potassium Pyrosulfate dissolves in the sample and completes the complete reaction of phosphate-phosphorus.

In the present invention, it is preferable to use CAS No .: 7790-62-7 to show more significant action and effect.

In the present invention, the Cas No. is consistently described and the characteristic of the compound is interpreted to include all compounds having the same or similar properties and physical or chemical properties as the Cas No. compound in the technical idea of the present invention. shall.

Ascorbic Acid (ascorbic acid) of the present invention is a substance that oxidizes the chemical formula C6H8O6.

Ascorbic acid was found to be an effective substance for scurvy, and in 1928 Hungarian A. Centzorzy separated it from the adrenal cortex of cattle. It is now industrially synthesized from sorbose via chitongulonic acid. In nature, it contains a lot of green tea, lemon, spinach, cabbage, etc., especially in the adrenal cortex in the animal body.

The present invention may be used to allow ascorbic acid synthesized or extracted by any of the above routes.

More preferably, the use of CAS No .: 50-81-7 results in more pronounced detection and effect.

In the present invention, Molybdate (molybdate) means a compound containing molybdenum (molibdenum) and oxygen acid (oxoanion) containing a high hexavalent high oxygen acid. Therefore, molybdate is named in various forms according to the number of cations of molybdenum and is also applicable to the present invention.

Therefore, Na2MoO4, CaMoO4, tetrabutylammonium salt, ethylenediamine salt, hexa-molybdate (tetramethylammonium salt), ammonium molybdate, sodium molybdate can be used.

In the present invention, especially sodium molybdate shows very good efficacy in terms of its measurement sensitivity.

As the sodium molybdate used in the present invention, it is more preferable to use CAS No .: 10102-40-6.

In the present invention, tartrate is also referred to as tartarate and is also referred to as ester or dicarboxylic acid of tartaric acid of an organic compound and is divided into sodium tartrate and potassium tartrate.

The present invention can use all of the above tartrate types. Preferably, it is preferable to use potassium tartrate, which serves to further promote the reaction in the sample.

More preferably, antimony potassium tartrate may be used among potassium tartrate.

As the antimony potassium tartrate used in the present invention, it is more preferable to use CAS No .: 28300-74-5.

Preferably, the detection reagent of the present invention is a powder detection reagent composed of 100 parts by weight of Potassium Pyrosulfate, 10 to 40 parts by weight of Ascorbic Acid, 4 to 20 parts by weight of Molybdate, and 1 to 5 parts by weight of tartrate.

In addition, the present invention is characterized in that the Molybdate is sodium molybdate, the tartrate is more preferably composed of a powder-type detection reagent characterized in that the antimony potassium tartrate.

The present invention performs the process of color development through a predetermined reaction time after adding a predetermined amount of the above-described phosphate-phosphorus detection reagent of the present invention to a predetermined amount of the sample containing phosphate-phosphorus.

The reaction time may be determined by the estimated concentration of phosphate-phosphorus contained in the sample, and usually about 1 to 10 minutes is good. The present invention is mainly a method for measuring low concentration of phosphate-phosphorus, so about 5 minutes is sufficient.

In addition, the amount of detection reagent added to the sample should be about 0.4 to 2 g based on the sample volume of 10 ml. However, the amount of detection reagent added to the sample is not necessarily limited thereto.

Phosphate-phosphate (PO ₄ -P, Phosphate) encountered with the powder detection reagent of the present invention during the reaction time was met with sodium molybdate in the powder detection reagent (Phosphomolybdate complex) ) Process.

In addition, the resulting phosphomolybdate complex (Phosphomolybdate complex) meets ascorbic acid (Ascorbic acid) to perform a process to change the color.

The present invention detects the phosphate-phosphate concentration by comparing or comparing this color change, that is, the developed color of the sample with the developed color by mixing the phosphate-phosphate detection reagent of the present invention with respect to the standard solution for each phosphate-phosphate concentration. Provide a method.

In the present invention, a method of contrasting or comparing the degree of color development between the sample and the standard solution may be employed in various ways. Preferably, the concentration of phosphate-phosphorus (particularly high concentration) may be calculated by using an absorbance method or a colorimetric control. Can be.

Therefore, the present invention can calculate the phosphate-phosphorus concentration contained in the sample by using the absorbance method or the colorimetric control method by mixing the phosphate-phosphorus detection reagent described above with the sample.

Absorbance spectroscopy, which is a conventional method for detecting phosphate-phosphorus concentration, includes a tin tin reduction method and an ascorbic acid reduction method.

1.Tinyl chloride reduction method

(1) Measuring principle

It is a method of quantifying phosphate phosphorus by measuring the absorbance of molybdenum blue produced by reducing ammonium, molybdate, produced by reacting phosphate with ammonium molybdate, with tin tin at 690 nm.

The range of quantitation is 0.002 ~ 0.05mg / l PO ₄ -P and the standard deviation is 10 ~ 2%.

(2) appliances and appliances

Photophotometer or photospectrometer

(3) Test method

A suitable amount of the filtered sample (containing 0.05 mg or less as a phosphate) is accurately taken and placed in a 50 ml volumetric flask to add about 40 ml.

If the sample is acidic, add p-nitrophenol solution (0.1W / V%) as an indicator and add sodium hydroxide solution (4W / V%) or ammonia water (1 + 10) to neutralize the solution until yellow.

Add 5 ml of ammonium molybdate solution and shake it, add about 0.25 ml of tin tin chloride solution (for phosphate test), add water to fill the mark, shake again, and leave it at 20 ～ 30 ℃ for 10 minutes. Transfer to a layer of 10 mm absorption cell to obtain a sample solution.

Separately, 40 ml of water is tested according to the test method of the sample, which is used as the blank test solution. Using the blank test solution as a control, measure the absorbance of the sample solution at 690 nm and calculate the concentration (mg / l) by calculating the amount of phosphate phosphorus from the calibration curve prepared in advance.

(4) Preparation of calibration curve

Take 1 ～ 10ml of phosphate standard solution (0.005mg P / mL) in 50ml volumetric flask, add water to make 40ml and test it according to the test method of sample. Create a line.

At this time, the time required to measure the absorbance after adding the coloring agent is 10 to 12 minutes.

In addition, when the concentration of phosphorus phosphate is small or when the coloring material coexists in the sample, the measurement sensitivity can be increased by using the following solvent extraction method.

Take an appropriate amount of sample (containing 0.01 mg PO ₄ -P or less) into a 125 ml separatory funnel, add water to about 50 ml, add 1 ml of sulfuric acid (1 + 50) and 15 ml of butyl alcohol, shake, stand, and separate the liquid. do. Transfer the aqueous layer to another separatory funnel, add 6.5 ml of ammonium molybdate solution, mix, add 0.25 ml of tin tin chloride solution, shake again, and leave for about 10 minutes.

Add 10 ml of butyl alcohol, shake and mix, extract blue molybdate and settle to separate the liquid. Transfer a portion of the butyl alcohol layer to a 10 mm long absorbent cell to prepare a sample solution. Separately, take 50 ml of water and test according to the test method for the sample.

Using the blank test solution as a control, absorbance is measured at around 730 nm and the concentration of phosphorus phosphate is obtained. The calibration curve is to dilute exactly 5 times of phosphate standard solution (0.005mg P / mL), take 1 ~ 10ml stepwise, and measure the absorbance by extracting operation as the test method of sample.

2. Ascorbic acid reduction method

(1) Measuring principle

It is a method of quantifying phosphate phosphorus by measuring the absorbance of blue molybdate acid produced by reducing phosphorus ammonium molybdate produced by reacting ammonium phosphate with ammonium molybdate to ascorbic acid at 880 nm. This method is applicable to samples containing a large amount of salts such as chlorides and sulfates.

The range of quantitation is 0.002 ~ 0.05mg / l PO ₄ -P and the standard deviation is 10 ~ 2%.

(2) appliances and appliances

Photophotometer or photospectrometer

(3) Test method

An appropriate amount of the filtered sample (containing 0.05 mg of phosphate) is taken into a 50 ml volumetric flask and water is added to make 40 ml.

If the sample is acidic, add p-nitrophenol solution (0.1W / V%) as an indicator and add sodium hydroxide solution (4W / V%) or ammonia water (1 + 10) to neutralize the solution until yellow.

Add 4 ml of ammonium molybdate-ascorbic acid mixture, add water to fill the mark, shake, and leave for 20 minutes at 20∼40 ℃. Transfer a portion of this solution to a layer-length 10nm absorber cell as a sample solution. Take 40 ml of water separately and test according to the test method for the sample. Using the blank test solution as a control, absorbance is measured at 880 nm (Note 2), the amount of phosphate is calculated from a calibration curve prepared in advance, and the concentration (mg / l) is calculated.

(4) Preparation of calibration curve

Take 1 ~ 10ml of phosphate standard solution (0.005mg PO ₄ -P / mL) step by step, put it into 50ml volumetric flask, add water to about 40ml and test according to the test method of the sample. Create a relationship line for.

In addition, when absorbance measurement is impossible at 880 nm, it measures at 710 nm.

If the concentration of phosphorus phosphate is small, transfer the sample solution which was left for 15 minutes after color development to 125 ml separatory funnel, add 10 ml of diisobutyl ketone (DIBK), shake for about 5 minutes, separate the solution, and discard the aqueous layer. The DIBK layer was transferred to an absorption cell, and the absorbance was measured at 640 nm. However, the calibration curve is prepared by taking 1 ~ 10 ml of the solution of ginseng salt standard solution (0.005mg PO ₄ -P / mL) diluted exactly 5 times with water and testing it according to the test method of sample.

The conventional methods described above have the disadvantage that the preparation of the measurement reagent and the test procedure are not only very complicated, but also require a lot of skill in the measurement method, and also require the intermediate treatment of the sample due to the presence of interference ions.

However, as described above, by using the phosphate-phosphorus powder detection reagent according to the present invention, the detection, preparation, test procedure, and method of such reagents can be significantly simplified. Effect.

The present invention can calculate the phosphate-phosphate concentration contained in the sample by using the absorbance method or colorimetric control method by mixing the phosphate-phosphorous powder detection reagent, which is a technical feature of the present invention, into the sample as described above. It is.

Absorption spectroscopy used in the present invention means a conventional method of obtaining the concentration of the target component by measuring the degree of light absorption at a specific wavelength by changing the target component in the sample solution into a light absorbing material with a suitable reagent, as mentioned above. .

The absorbance method of the present invention obtains the concentration of a target component by applying Lambert Beer's law. A typical absorbance analyzer includes a light source unit, a wavelength selection unit, a sample unit, and a photometric unit.

As a method of measuring the concentration in the absorbance method, there is a colorimetric method using the degree of color development, and a turbidity method using the degree of suspension of the sample solution. Absorption spectroscopy makes a control solution corresponding to the sample liquid to measure the absorbance, and accordingly prepares a calibration curve and then measures the absorbance of the sample liquid and compares the concentration with the calibration curve.

In the present invention, both the colorimetric method and the colorimetric method can be used, and preferably, the colorimetric method has high accuracy.

In addition, the colorimetric contrast method is as follows.

As described above, a standard solution is prepared according to various concentrations of a desired component, and a reference colorimetric table is set by adding the phosphate-phosphorus detection reagent of the present invention to the standard solution.

And it means a method of measuring the concentration of the sample solution by comparing the degree of color development resulting from the mixing reaction by mixing the above-described phosphate-phosphorus detection reagent to the sample.

For this reason, any method of measuring the concentration using the degree of miscibility of the phosphate-phosphorus detection reagent of the present invention by mixing the sample will be included in the technical content of the present invention.

An embodiment according to the present invention will be described. Embodiment of the present invention is not intended to limit the technical content of the present invention and should not be construed to reduce the scope of rights.

<Examples>

1. A phosphate-phosphorous powder detection reagent of the present invention is prepared as follows.

<Reagent 1>

Synonyms: Potassium Pyrosulfate, CAS No .: 7790-62-7, 74g

<Reagent 2>

Synonyms: Ascorbic Acid, CAS No .: 50-81-7, 20g

<Reagent 3>

Synonyms: Sodium Molybdate, CAS No .: 10102-40-6, 4g

<Reagent 4>

Synonyms: Potassium Antimonly tartrate, CAS No .: 28300-74-5, 1g

It is prepared by mixing.

2. High concentration phosphate-phosphorus concentration detection process

(1) absorbance spectroscopy

1) 1 ml of the prepared detection reagent is added to 10 ml of the sample containing phosphate-phosphorus to induce color development.

The reaction time was about 1 minute.

The measuring vessel was a 5 inch diameter round glass bottle, and the measuring wavelength was 430 nm.

2) Prepare calibration curve for standard solution.

The control calibration curve for the standard solution is shown in FIG. 1.

Accurate phosphate-phosphate concentration is measured by comparing the absorbance of the control sample and the sample.

(2) colorimetric contrast method

As described above, a colorimetric table for the standard solution is prepared to compare the degree of color development for the color-induced sample to calculate a low concentration of phosphate-phosphorus.

As shown in Table 1 below, the present invention exhibits a high limit that can exclude the effects of ion interference.

Therefore, when using the phosphate-phosphorus concentration detection method according to the present invention it can be seen that the effect of significantly reducing the effect of interference by other kinds of ions contained in the sample.

Interference Limit value (mg / l) K +, Na +, Cl- 100 mg / l COD 100 mg / l Ag + 500 mg / l Cr6 + 100 mg / l Ferric ion 100 mg / l Nitrite 10,000 mg / l Pb2 +, Zn2 +, Hg2 +, Cd2 +, Sn2 + 5,000 mg / l NH3 + 20,000mg / l

As described above, the present invention provides a method for detecting a low concentration of phosphate-phosphorus using a phosphate-phosphorus detection reagent, which is a feature of the present invention.

The present invention can be widely used in water purification and sewage water treatment business, pollution prevention business, education business, etc. related to the Framework Act on Water Environment.

In addition, the present invention can be widely used for pollution prevention monitoring industry, environmental policy related business of national and local government.

In addition, it is a very useful invention for water quality analysis chemicals business, water quality analysis chemical manufacturing industry, environmental supervision business, environmental modeling business, environmental impact assessment business and educational data providing business.

Claims (3)

In the sample containing the low concentration of phosphate-phosphorus,
Potassium Pyrosulfate, Ascorbic Acid are mixed,
CaMoO4, tetrabutylammonium salt, ethylenediamine salt, hexa-molybdate (tetramethylammonium salt) is mixed,
process of inducing color change by adding a certain amount of the detection reagent mixed with sodium tartrate
A method for detecting a low concentration of phosphate phosphorus by comparing the induced color change with the colorimetric table for the standard solution.
In the sample containing the low concentration of phosphate-phosphorus,
Potassium Pyrosulfate, Ascorbic Acid are mixed,
CaMoO4, tetrabutylammonium salt, ethylenediamine salt, hexa-molybdate (tetramethylammonium salt) is mixed,
process of inducing color change by adding a certain amount of the detection reagent mixed with sodium tartrate
The method for detecting a low concentration of phosphate phosphorus by using the absorbance method for the degree of color change induced.
3. The method according to claim 1 or 2,
100 parts by weight of Potassium Pyrosulfate, 10-40 parts by weight of Ascorbic Acid,
4 to 20 parts by weight of a reagent of any one of CaMoO 4, tetrabutylammonium salt, ethylenediamine salt and hexa-molybdate (tetramethylammonium salt),
A method for detecting a low concentration of phosphate phosphorus, characterized by mixing a detection reagent mixed with 1 to 5 parts by weight sodium tartrate.

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