JP2010127830A - Method and apparatus for quantifying hydrogen peroxide - Google Patents

Abstract

A hydrogen peroxide determination method and a hydrogen peroxide determination apparatus capable of accurately and continuously determining the hydrogen peroxide concentration in a sample solution are provided.
A sample solution containing hydrogen peroxide is contacted with a hydrogen peroxide decomposition catalyst supporting platinum, and a dissolved oxygen concentration in a processing solution is measured by an optical oxygen sensor, and the sample is calculated from the dissolved oxygen concentration. A method for quantifying hydrogen peroxide that quantifies the concentration of hydrogen peroxide in a solution. Further, in the above method, when the dissolved oxygen in the sample solution is measured before hydrogen peroxide decomposition, the accuracy is improved. Further, after supplying a sample solution containing hydrogen peroxide to the optical oxygen sensor and measuring the dissolved oxygen concentration in the sample solution, the solution is converted into a hydrogen peroxide decomposition catalyst supporting platinum and the sample solution by a switching means. After the contact with each other, the dissolved oxygen concentration in the processing solution is measured by the optical oxygen sensor, and the hydrogen peroxide concentration in the sample solution is determined from the dissolved oxygen concentrations obtained by the optical oxygen sensor. It can also be quantified.
[Selection] Figure 1

Description

  The present invention relates to a method for quantifying hydrogen peroxide for measuring the concentration of hydrogen peroxide in a sample solution containing hydrogen peroxide, and a quantification apparatus therefor.

Hydrogen peroxide is used as a cleaning agent, a bleaching agent, a disinfectant and the like in foods, pharmaceuticals, paper pulp, fibers, and the electronics industry because of its excellent oxidizing action. In particular, in semiconductor and liquid crystal manufacturing factories and the like, they are used for cleaning electronic components and sterilizing and disinfecting manufacturing plants. In the field of water treatment, oxidants such as ozone are used to treat substances to be treated. As a result, hydrogen peroxide is generated as a by-product, and hydrogen peroxide is decomposed to prevent adverse effects in the post-treatment process. Need to disappear. In particular, when this treated water is discharged out of the system as discharged water, it is necessary to completely decompose the hydrogen peroxide contained therein.
In the water treatment field that handles such water and wastewater, it is highly necessary that the concentration of hydrogen peroxide must be continuously and accurately grasped and managed.

Conventionally known methods for measuring the concentration of hydrogen peroxide are iodometric titration, absorptiometry using titanium sulfate and permanganic acid. However, these methods are not suitable for continuous measurement and the sensitivity is not sufficient.
Therefore, a method for measuring hydrogen peroxide by an luminescence method using an enzyme (Patent Document 1), a method for measuring hydrogen peroxide by ultraviolet spectroscopic analysis (Patent Document 2), and decomposing hydrogen peroxide in a sample water into dissolved oxygen. A method of calculating the hydrogen peroxide concentration in the sample water (Patent Document 3) has been proposed.
In the invention method described in Patent Document 1, a sample solution containing a chemiluminescent substance that emits light by reacting with hydrogen peroxide is reacted in the presence of a catalytic enzyme, and a chemiluminescence amount proportional to the hydrogen peroxide concentration is measured with an optical sensor. A hydrogen peroxide sensor using luminol as a chemiluminescent substance and peroxidase as a catalytic enzyme is used.
On the other hand, in the method described in Patent Document 2, the concentration of hydrogen peroxide in a sample solution containing hydrogen peroxide and a component that interferes with the measurement of the concentration of hydrogen peroxide, the amount of transmitted UV light of the sample solution, and the sample The measurement is performed by estimating from the ratio to the amount of transmitted ultraviolet light obtained by decomposing and removing a predetermined amount of hydrogen peroxide from the solution.
In the description of Patent Document 2, a sample solution tank, a hydrogen peroxide decomposition tank, and a three-way switching valve are provided, and a coiled platinum wire as a hydrogen peroxide decomposition catalyst is disposed in the decomposition tank. A vibration motor is also attached to the decomposition tank to promote hydrogen peroxide decomposition. The hydrogen peroxide concentration-attenuated sample is prepared by holding for 10 minutes in a decomposition tank, for example, and is appropriately switched to the sample solution by a three-way switching valve and supplied to the spectroscopic analyzer.
In the method described in Patent Document 3, the hydrogen peroxide decomposition part having the sample water from the water treatment process and the dissolved oxygen measuring part are passed through, and the hydrogen peroxide concentration in the sample water is calculated.

However, in the method described in Patent Document 1, since the measurement of hydrogen peroxide is caused by an enzyme reaction in the membrane containing the enzyme, the amount of light emitted with respect to the amount of hydrogen peroxide varies depending on the enzyme activity affected by temperature or the like. Or a chemiluminescent substance must be contained in the sample solution to be measured, so that the measurement is inevitably batch-type, and stable measurement is difficult. It was not suitable for applications where hydrogen peroxide in the solution was constantly monitored.
Also in the method described in Patent Document 2, the above-described spectroscopic measurement method using ultraviolet rays requires a broadband light source in the ultraviolet region, that is, a large discharge tube (such as a mercury lamp or a xenon lamp) and a power source that require high voltage. In order to reduce wavefront aberration due to the short wavelength of ultraviolet spectroscopic measurement equipment, it is necessary to use optical components with high accuracy and excellent ultraviolet transmittance by the ratio of wavelength compared to visible light. As a result, the apparatus becomes larger, heavier, and more expensive. In addition, the spectroscopic measurement method using ultraviolet rays has a problem in that the hydrogen peroxide concentration cannot be accurately measured because the absorption spectrum of the interfering substance in the sample solution often covers the absorption spectrum of hydrogen peroxide.
Neither method is particularly suitable for applications in which hydrogen peroxide in a large amount of sample solution is continuously monitored.
On the other hand, the method described in Patent Document 3 is a method that can automate the hydrogen peroxide concentration of the specimen water, but there is a description that the dissolved oxygen measuring means is constituted by a known dissolved oxygen meter. If such a known dissolved oxygen meter is not always maintained sufficiently, an error occurs immediately. Therefore, even if the measurement itself can be automated, maintenance of the apparatus may be difficult.
Furthermore, the hydrogen peroxide decomposition means described in Patent Document 3 is also exemplified by metal catalysts (such as Pt), but it is described that activated carbon and synthetic adsorbents are particularly suitable. However, these materials are not active. Since it is not sufficient, a large amount of material may be required and the exchange frequency may increase.

JP-A-2-86798 JP 2002-139430 JP 2005-274386 A

  An object of the present invention is to provide a hydrogen peroxide quantification method and a hydrogen peroxide quantification device capable of quantifying the hydrogen peroxide concentration in a sample solution accurately, rapidly, and continuously as necessary. And

As a result of intensive studies to solve the above problems, the present inventors have conceived the method of the present invention and found that the object can be achieved.
That is, the gist of the present invention is as follows.
1. After the sample solution containing hydrogen peroxide is brought into contact with the hydrogen peroxide decomposition catalyst supporting platinum, the dissolved oxygen concentration in the treatment solution is measured by a photo-oxygen sensor, and the excess oxygen in the sample solution is measured from the dissolved oxygen concentration. A method for quantifying hydrogen peroxide, characterized in that the concentration of hydrogen oxide is quantified.
2. The dissolved oxygen concentration in the sample solution containing hydrogen peroxide and the dissolved oxygen concentration in the treatment solution after the platinum-supported hydrogen peroxide decomposition catalyst was brought into contact with the sample solution were measured with an optical oxygen sensor. A method for quantifying hydrogen peroxide, comprising quantifying the hydrogen peroxide concentration in the sample solution from both dissolved oxygen concentrations obtained by the optical oxygen sensor.
3. After supplying the sample solution containing hydrogen peroxide to the optical oxygen sensor and measuring the dissolved oxygen concentration in the sample solution, the sample solution was brought into contact with the hydrogen peroxide decomposition catalyst supporting platinum by the switching means. Thereafter, the dissolved oxygen concentration in the processing solution is measured by the optical oxygen sensor, and the hydrogen peroxide concentration in the sample solution is quantified from both dissolved oxygen concentrations obtained by the optical oxygen sensor. Method for determining hydrogen peroxide.
4. The method for quantifying hydrogen peroxide according to any one of 1 to 3, wherein the sample solution is degassed and then brought into contact with the hydrogen peroxide decomposition catalyst.
5). 5. The method for quantifying hydrogen peroxide according to any one of 1 to 4 above, wherein the platinum contains 0 to 200 ppm by mass of a protective colloid-forming agent.
6). 6. The method for quantifying hydrogen peroxide according to any one of 1 to 5 above, wherein the platinum is platinum nanoparticles.
7). 7. The method for quantifying hydrogen peroxide according to 6 above, wherein the platinum nanoparticles are particles having a volume average particle diameter of 1 to 50 nm.
8). 8. The method for quantifying hydrogen peroxide according to any one of 1 to 7, wherein the hydrogen peroxide decomposition catalyst has platinum supported on a surface having an anion exchange group.
9. 9. The method for quantifying hydrogen peroxide according to any one of 1 to 8 above, wherein the optical oxygen sensor is excited by visible light and detects dissolved oxygen by fluorescence or phosphorescence.
10. 10. The method for quantifying hydrogen peroxide according to any one of 1 to 9, wherein the sample solution containing hydrogen peroxide is continuously supplied, and the hydrogen peroxide concentration is continuously quantified.
11. A sample solution supply means containing hydrogen peroxide, a hydrogen peroxide decomposition tank filled with a hydrogen peroxide decomposition catalyst supporting platinum, a dissolved oxygen measuring means by an optical oxygen sensor, and a dissolved oxygen measuring means by the optical oxygen sensor. A calculating means for calculating the hydrogen peroxide concentration in the sample solution from the measured dissolved oxygen concentration; a means for supplying the sample solution from the sample solution supplying means to the hydrogen peroxide decomposition tank; and the hydrogen peroxide decomposition tank And a means for supplying the processing solution from the above to the dissolved oxygen measuring means by the optical oxygen sensor.
12 Sample solution supply means containing hydrogen peroxide, dissolved oxygen measuring means A using an optical oxygen sensor, a hydrogen peroxide decomposition tank filled with a hydrogen peroxide decomposition catalyst carrying platinum, and dissolved oxygen measuring means B using an optical oxygen sensor And calculating means for calculating the hydrogen peroxide concentration in the sample solution from the dissolved oxygen concentrations measured by the dissolved oxygen measuring means A and B by the optical oxygen sensor, and the sample solution from the sample solution supplying means. Means for supplying dissolved oxygen measuring means A by the optical oxygen sensor; means for supplying effluent from the dissolved oxygen measuring means A to the hydrogen peroxide decomposition tank; and treatment liquid from the hydrogen peroxide decomposition tank. Means for supplying the dissolved oxygen measuring means B by the optical oxygen sensor;
13. Hydrogen peroxide decomposition tank filled with hydrogen peroxide decomposition catalyst supporting platinum, dissolved oxygen measuring means using optical oxygen sensor, dissolved oxygen measuring means using optical oxygen sensor for sample solution containing hydrogen peroxide, or platinum A sample solution supply means having a switching means capable of being supplied to any one of the hydrogen peroxide decomposition tanks filled with the supported catalyst, and a processing solution from the hydrogen peroxide decomposition tank filled with the platinum-supported catalyst as the optical oxygen sensor. Supplying the dissolved oxygen measuring means by the optical oxygen sensor, the dissolved oxygen concentration measured by the dissolved oxygen measuring means by the optical oxygen sensor, and the treatment liquid from the hydrogen peroxide decomposition tank filled with the platinum-supported catalyst to the optical oxygen sensor. And a calculating means for calculating the hydrogen peroxide concentration in the sample solution from the dissolved oxygen concentration measured by the dissolved oxygen measuring means by .
14 14. The hydrogen peroxide concentration quantification apparatus according to any one of the above 11 to 13, wherein the hydrogen peroxide decomposition tank is equipped with a deaeration device.
15. 15. The apparatus for quantitatively determining a hydrogen peroxide concentration according to any one of the above 11 to 14, wherein the platinum contains 0 to 200 mass ppm of a protective colloid-forming agent.
16. 16. The apparatus for determining a hydrogen peroxide concentration according to any one of the above 11 to 15, wherein the platinum is platinum nanoparticles.
17. 17. The hydrogen peroxide concentration quantification apparatus according to 16, wherein the platinum nanoparticles are particles having a volume average particle diameter of 1 to 50 nm.
18. 18. The apparatus for quantitatively determining a hydrogen peroxide concentration according to any one of the above 11 to 17, wherein the hydrogen peroxide decomposition catalyst has platinum supported on a surface having an anion exchange group.
19. 19. The apparatus for quantitatively determining a hydrogen peroxide concentration according to any one of the above 11 to 18, wherein the optical oxygen sensor is excited by visible light and detects dissolved oxygen by fluorescence or phosphorescence.
20. 20. The hydrogen peroxide concentration quantification apparatus according to any one of the above 11 to 19, wherein the sample solution containing hydrogen peroxide is continuously supplied and the hydrogen peroxide concentration is continuously quantified.

  According to the present invention, a hydrogen peroxide quantification method and a hydrogen peroxide quantification apparatus capable of accurately, rapidly, and continuously quantifying the hydrogen peroxide concentration in a sample solution as needed. Can be provided.

In the present invention, a material having as high a hydrogen peroxide decomposition capability as possible and not containing impurities and elution is used in an optimal form, and only oxygen generated by the decomposition of hydrogen peroxide is measured. Hydrogen peroxide in the sample solution is decomposed using a catalyst supporting platinum, and the dissolved oxygen generated at that time is measured with an optical oxygen sensor to quantify the hydrogen peroxide concentration in the sample solution. The method and apparatus for determining the hydrogen peroxide concentration of the present invention will be described with reference to FIGS.
First, FIG. 1 is a flow chart showing an embodiment of the present invention using two optical oxygen sensors. The dissolved oxygen measuring means 10 using the optical oxygen sensor A (hereinafter simply referred to as the optical oxygen sensor A). ), A means for supplying a sample solution containing hydrogen peroxide to the optical oxygen sensor A (hereinafter sometimes simply referred to as a sample solution supply means) 3, and a hydrogen peroxide decomposition tank filled with a platinum-supported catalyst ( Hereinafter, it may be simply referred to as a hydrogen peroxide decomposition tank.) 2, dissolved oxygen measuring means 10 using the optical oxygen sensor B (hereinafter sometimes simply referred to as the optical oxygen sensor B), and the optical oxygen sensor A. Means 4 for supplying the effluent from the hydrogen peroxide decomposition tank 2 (hereinafter sometimes simply referred to as effluent supply means) 4 and the treatment liquid from the hydrogen peroxide decomposition tank 2 for the optical oxygen sensor. Means for supplying to B (hereinafter simply referred to as processing liquid supply means) There are Ukoto.) And 5, the dissolved oxygen concentration measured by the optical sensors A and B, comprises a, an arithmetic unit (not shown) for calculating the concentration of hydrogen peroxide in the sample solution. The effluent from the optical oxygen sensor B is discharged from the measurement system by the sample solution discharge means 6.

Next, FIG. 2 is a flowchart showing another embodiment of the present invention. In FIG. 3 and FIG. 4, the same numbers are assigned to the common members.
FIG. 2 shows a flow in which, instead of installing two optical oxygen sensors as shown in FIG. 1, a switching means is arranged in the sample supply means so that measurement can be performed with one optical oxygen sensor. .
That is, the sample solution containing hydrogen peroxide is supplied to the dissolved oxygen measuring means 10 (hereinafter sometimes simply referred to as oxygen sensor C) by the optical oxygen sensor C, and to the hydrogen peroxide decomposition tank 2. The sample solution supply means 3 provided with the supply pipe 3b and the pipes 3a and 3b provided with the switching means 8 and 9, respectively, and the treatment liquid from the hydrogen peroxide decomposition tank 2 are fed by the treatment liquid supply means 5. The oxygen sensor C is supplied.
According to this flow, first, the switching valve 8 is opened, the switching valve 9 is closed, the sample solution is supplied to the optical oxygen sensor C, the dissolved oxygen in the sample solution is measured, and then the switching valve 8 is closed and switched. The flow path of the sample solution is switched by opening the valve 9 and supplied to the hydrogen peroxide decomposition tank 2, where hydrogen peroxide is decomposed to generate oxygen, and then the processing liquid is supplied to the light by the processing liquid supply means 5. The concentration of the hydrogen peroxide can be measured by supplying the oxygen sensor C.
Here, in FIG. 2, the treatment liquid supply means 5 provided in the hydrogen peroxide decomposition tank 2 is shown to join the pipe 3a, but it may be directly connected to the optical oxygen sensor C. good. Further, in FIG. 2, a switching unit having two switching valves is shown, but the present invention is not limited thereto, and for example, a switching unit using one three-way valve may be adopted.
If the flow of FIG. 2 is adopted, only one optical oxygen sensor needs to be used, which is more economical.
In the present invention, a solution adjusting tank may be provided when the flow rate of each means is different, but it is not shown in FIGS.
In the present invention, it is preferable to deaerate the sample solution with a deaeration device (not shown) before contacting with the hydrogen peroxide decomposition catalyst because the measurement accuracy can be improved.
Examples of such a degassing device include a nitrogen gas purge degassing device, a vacuum distillation device, and a membrane degassing device.

  The sample solution containing hydrogen peroxide in the present invention is not particularly limited as long as it is a solution for measuring or monitoring the hydrogen peroxide concentration. For example, it is used in foods, pharmaceuticals, paper pulp, fibers, and the electronics industry. And cleaning agents containing hydrogen peroxide, bleaching agents, and disinfecting agents. In particular, pure water used in semiconductor and liquid crystal manufacturing factories, ultrapure water, wastewater treatment plants, treated water and effluent water in sewage treatment plants, and the like. Among these, the present invention is suitably used as a hydrogen peroxide quantification means for solution systems that need to be continuously monitored.

  In the present invention, a part of the sample solution is sampled from the target solution system containing hydrogen peroxide and supplied to the optical oxygen sensor and the hydrogen peroxide decomposition tank in the present invention. As such a sample solution supply means 3, any means may be adopted, and a commercially available sampling apparatus can be adopted. The sample solution supply means 3 is provided with a metering pump so that a constant flow rate of the sample solution is supplied to the measurement means and the hydrogen peroxide decomposition tank.

The sample solution sampled is supplied to the optical oxygen sensor A or C. The measurement of dissolved oxygen by the optical oxygen sensor A or C is already included in the sample solution in order to increase the measurement accuracy of the hydrogen peroxide concentration. If the dissolved oxygen is not included at all or the amount of dissolved oxygen is known in advance, it is not necessary to perform this. In the case of FIG. What is necessary is just to measure dissolved oxygen with the optical oxygen sensor C after supplying to the hydrogen oxide decomposition | disassembly tank 2. FIG.
In the above description, it is preferable that the optical oxygen sensors A, B and C are all capable of being excited by visible light and detecting dissolved oxygen by fluorescence or phosphorescence. The optical oxygen sensors A and B are preferably the same (hereinafter, the optical oxygen sensors A, B and C may be collectively referred to as the optical oxygen sensor 1).
In contrast, the use of oxygen sensors of a conventional electrochemical, it takes time to reach equilibrium during startup of the apparatus, the measurement error for reasons such as control of the flow rate is difficult is increased.

Examples of the optical oxygen sensor 1 that can be excited by visible light and can detect dissolved oxygen by fluorescence or phosphorescence include the following.
I. Contains a first layer containing a hydrophobic functional group having an amino group and a silane coupling agent having a hydrophilic functional group as an oxygen sensing material on a substrate such as glass and a fat-soluble functional substance such as porphyrin An oxygen sensor provided with a second layer made of dried gel in this order (see JP-A-2006-189271).
II. An oxygen sensor equipped with an optical oxygen sensor chip provided with a hydrolysis / polymerization film of a silane alkoxide having an alkyl group or an aryl group containing a porphyrin compound as an oxygen sensing material on a substrate such as glass (Japanese Patent Laid-Open No. 2008-14896) Issue no.).
III. An optical oxygen sensor in which a ruthenium complex is dispersed in rubber or plastic as an oxygen sensing material (see JP-A-2002-501363).
IV. Effect of Processing Temperature on the Oxygen Quenching Behavior of Tris (4,7 '-diphenyl-1,10'-phenanthroline) Ruthenium (II) Sequestered Within Sol-Gel-Derived Xerogel Films. See Journal of Sol-Gel Science and Technology 1771-82 2000).
In the present invention, the sample solution can be measured either batchwise or continuously. In particular, among the oxygen sensors exemplified above, the sensors described in I and II are excellent in both sensitivity and life, and are continuously used. Therefore, it is preferable as an oxygen sensor used in the present invention. However, it is not limited thereto, and other known optical oxygen sensors may be employed.

An embodiment of the dissolved oxygen measuring means using such an optical oxygen sensor 1 will be described with reference to FIGS. In FIG. 3 and FIG. 4, the same numbers are assigned to the common members.
In the dissolved oxygen measuring means 10 including the optical oxygen sensor 1 of FIG. 3, unnecessary spectrum other than necessary is cut out of the excitation light irradiated from the excitation light source 11 by the excitation filter 12, and the above-described spectrum is transmitted via the bundle fiber 13. The oxygen sensing material 14 is irradiated. Then, by using the quenching action of the fluorescence or phosphorescence generated in the oxygen sensing material 14, it is sent to the light receiving filter 15 via the bundle fiber 13, where unnecessary spectral components such as stray light of the excitation light are cut, The light receiver 16 is configured to selectively detect the light emission amount of only the wavelength. The sample solution flows through the sample solution flow path 17 and is in direct contact with the oxygen sensing material 14 on the way.

  On the other hand, in FIG. 4, the excitation light is incident on the optical fiber 23 from the excitation light source 11 through the coupling lens 22, and the excitation light is coupled to the optical fiber 25 by the optical demultiplexer / multiplexer 24. The oxygen sensing material 14 is irradiated through 26. Then, using the quenching action of fluorescence or phosphorescence generated in the oxygen sensing material 14, it is coupled again to the optical fiber 25 through the objective lens 26, and then coupled to the optical fiber 27 by the optical demultiplexer / multiplexer 24. It is configured to be detected by the light receiver 16 through the lens 28. The flow of the sample solution is the same as in FIG.

Here, as the excitation light source 11, any light source that emits light having a wavelength suitable for the photo-oxygen sensing material 14 described later, which is dispersedly supported on the surface of the glass substrate 29, can be adopted. Examples include a green LED, a white LED, a halogen lamp, a discharge tube, a green laser, and the like.
As the light receiver 16, any optical oxygen sensing material 14 can be used as long as it can detect the quenching action of fluorescence or phosphorescence generated by detecting dissolved oxygen. As an example, a photomultiplier, Examples include avalanche photodiodes and photodiodes.
Arbitrary optical fibers can be used as the bundle fiber 13 and the optical fibers 23, 25, and 27, but a large-diameter optical fiber made of quartz or an image bundle made of quartz or the like with little autofluorescence is shown as a suitable example.
In these optical oxygen sensors, the quenching action by oxygen is in accordance with the Stern-Volmer rule (I = I ₀ [O ₂ ] (where I: luminescence, I ₀ : material constant, [O ₂ ]: oxygen concentration). The amount of luminescence and the oxygen concentration are proportional to each other.)

The sample solution whose dissolved oxygen concentration has been measured in advance as described above is then supplied to the hydrogen peroxide decomposition tank 2 by the effluent supply means 4 or the pipe 3b.
The hydrogen peroxide decomposition tank used here is a tank filled with a hydrogen peroxide decomposition catalyst 7 capable of decomposing hydrogen peroxide in contact with a hydrogen peroxide-containing liquid and generating oxygen.
In the present invention, platinum particles are employed as the hydrogen peroxide decomposition catalyst 7 because of its high hydrogen peroxide resolution.
With the same platinum group metal, palladium has a high hydrogen peroxide decomposition ability, but also has the ability to absorb hydrogen, so oxygen generated by the decomposition of hydrogen peroxide reacts with hydrogen on the palladium surface to produce water. To do. For this reason, there exists a problem that the produced | generated water interferes and cannot measure correctly.
On the other hand, platinum does not have such a problem, and has higher catalytic activity than palladium.
In the present invention, even when platinum is used, particularly when platinum nanoparticles having a volume average particle diameter of 1 to 50 nm, preferably 1.2 to 20 nm are used, the surface area is increased and the contact efficiency is increased. It is desirable because hydrogen decomposition efficiency is improved.
If the volume average particle size is less than 1 nm, the hydrogen peroxide decomposition activity may decrease. Conversely, if the volume average particle size exceeds 50 nm, the specific surface area of the metal nanoparticles may decrease, and the decomposition activity may also decrease. is there.
Furthermore, in the present application, the platinum is preferably a protective colloid-forming agent in an amount of 0 to 200 ppm by mass, that is, a type that does not substantially contain the protective colloid-forming agent because it can exhibit the maximum catalytic activity. . In addition, platinum that does not contain a protective colloid-forming agent does not contain extra components, so organic substances do not interfere with catalyst activity, cause contamination, or cause side reactions. This is extremely important for measurement in extremely pure systems such as pure water.
From these points, platinum nanoparticles that do not contain a protective colloid-forming agent are particularly suitable.

In the present invention, these platinum group nanoparticles can be used as they are, but it is preferable to support the nanoparticles using a carrier because of problems such as operability and activity efficiency.
The carrier is not limited as long as it can support platinum group nanoparticles, and any carrier can be employed.For example, magnesia, titania, alumina, silica-alumina, zirconia, activated carbon, zeolite, Examples thereof include diatomaceous earth and ion exchange resins. Among these, anion exchange resins can be particularly preferably used for the following reasons.
That is, since the platinum group nanoparticles have an electric double layer and are negatively charged, they are stably supported on the anion exchange resin and difficult to peel off. The platinum group nanoparticles supported on the anion exchange resin are This is because it shows a strong catalytic activity for hydrogen decomposition and removal.
Such an anion exchange resin is preferably a strongly basic anion exchange resin based on a styrene-divinylbenzene copolymer, and more preferably a gel type resin. The exchange group of the anion exchange resin is preferably in the OH form. In the OH-type anion exchange resin, the resin surface becomes alkaline and promotes decomposition of hydrogen peroxide.

In the present invention, the amount of platinum group nanoparticles supported on the carrier, particularly an anion exchange resin, is preferably 0.01 to 5% by mass, and more preferably 0.04 to 1% by mass.
If the supported amount of platinum group nanoparticles is less than 0.01% by mass, the catalytic activity for the decomposition and removal of hydrogen peroxide may be insufficient. The supported amount of platinum group nanoparticles is 0.2 mass% or less, and sufficient catalytic activity is exhibited for the decomposition and removal of hydrogen peroxide. Usually, when the platinum group nanoparticles are supported exceeding 5 mass%, In addition to becoming an economy, there is a risk of elution of platinum into water.
In the present invention, the filling method of the hydrogen peroxide decomposition catalyst containing platinum group nanoparticles may be a fluidized bed method or a fixed bed method.
Further, it is preferable that the liquid passing rate is as close as possible to the decomposition efficiency of the hydrogen peroxide contained therein, and the space velocity is usually about 500 / h to 1 / h. From the viewpoint of decomposition efficiency, it is more preferably about 100 / h to 10 / h.
The treatment liquid in which hydrogen peroxide is decomposed and dissolved oxygen is generated is then sent to the optical oxygen sensor B or C via the treatment liquid supply means 5, where the dissolved oxygen concentration is measured in the same manner as described above. Thereafter, the sample solution is discharged through the sample solution discharging means 6.

As described above, when the dissolved oxygen before and after the hydrogen peroxide in the sample solution is decomposed is measured, the information is sent to the calculation means such as the computer of the present invention. Of course, if the dissolved oxygen is not included in the sample solution or the amount is a known amount, the value may be input in advance.
In the calculation means, the amount of hydrogen peroxide is calculated according to the following hydrogen peroxide quantitative principle.
When hydrogen peroxide in the sample solution comes into contact with the platinum group nanocolloidal metal particle catalyst, hydrogen peroxide is decomposed to generate oxygen according to the following formula.
2H ₂ O ₂ → 2H ₂ O + O ₂
When the dissolved oxygen concentration in the sample solution is sufficiently smaller than the dissolved oxygen concentration, the total amount of oxygen thus dissolved is dissolved in the sample solution. The dissolved oxygen concentration increases as compared with the sample solution.
Here, the decomposition efficiency of the hydrogen peroxide decomposition catalyst (= the ratio of hydrogen peroxide actually contacted with the decomposition catalyst to be decomposed by the above reaction) is α, per unit volume present in the sample solution. If the amount of dissolved oxygen is M and the amount of hydrogen peroxide is N, the amount of dissolved oxygen per unit volume after contacting the cracking catalyst is expressed as M + α (N / 2).
By measuring this increase α (N / 2), the hydrogen peroxide amount N contained in the sample solution can be obtained.
The decomposition efficiency of the hydrogen peroxide decomposition catalyst varies greatly depending on the material, structure, surface area, support material, loading method, flow rate, etc. of the white metal catalyst. As described above, the amount of dissolved oxygen generated when α is close to 1 increases, so that the hydrogen peroxide detection performance is improved. Further, α can be made close to 1 by reducing the flow rate of the sample solution.
Thus, the obtained result may be displayed or printed by an appropriate output means.

  As described above, in the present invention, the change in the dissolved oxygen concentration before and after the sample solution is treated with the hydrogen peroxide decomposition catalyst is measured by an optical oxygen sensor using visible light, and the difference in dissolved oxygen concentration is measured. As a result of the evaluation, it is possible to realize a small, lightweight and low-cost method for determining hydrogen peroxide that can accurately, continuously and stably monitor the hydrogen peroxide concentration even in a large amount of sample solution.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited to this Example at all.
The apparatus configuration used in the examples of the present invention is as follows.
I. Optical oxygen sensor 1) Oxygen sensing material A heterocyclic compound (porphyrin compound) and transition metal complex compound (ruthenium (II) complex) that can be excited by visible light and have an oxygen quenching property are dispersed in a sol-gel glass matrix. Use supported one.
2. Photo-oxygen sensor shown in FIG. 3 The excitation light source uses a green LED with a wavelength of 530 nm. A 7-core bundle fiber with a core diameter of 200 μm is used for the bundle fiber. The light receiving wavelength is selected according to the red phosphorescence with a wavelength of 650 nm, and a photomultiplier is used for the light receiver.
3. Photo-oxygen sensor shown in FIG. 4 The excitation light source uses a green LED with a wavelength of 530 nm. The optical demultiplexer / multiplexer has a cutoff wavelength of 580 nm. The light emission amount of only the red phosphorescent component at 650 nm was selectively measured. A photomultiplier is used for the receiver. For the optical fiber, a large-diameter optical fiber made of quartz (core diameter 200 μm) with little autofluorescence is used.
II. Hydrogen peroxide decomposition tank Ratio of 0.1% by mass of platinum nanocolloid metal having a volume average particle size of 3.5 nm to OH type strongly basic gel type anion exchange resin based on styrene-divinylbenzene copolymer 20 ml of the catalyst supported in (1) was filled in a container. The supply rate of the sample solution was set to a space velocity of 50 / h so that the decomposition efficiency α = 100%. In addition, a membrane type deaerator (Mac Ace, manufactured by Kurita Kogyo Co., Ltd.) was placed in front.
III. Piping Stainless steel piping that does not penetrate oxygen from outside is adopted.

In addition, it was 20,3 ppb as a result of analyzing the said ultrapure water by the phenolphthali absorption photometry method by manual analysis.

Example 1
The present invention was implemented with an apparatus having the configuration shown in FIG. 1 equipped with the optical oxygen sensor shown in FIG.
The hydrogen peroxide sample solution used is ultrapure water used in a certain semiconductor manufacturing factory. A sampling device is attached to a part of the ultrapure water supply pipe, and the oxidization generated as a result of TOC removal by UV oxidation. A sample solution containing hydrogen was supplied.
The oxygen concentration was measured after about 5 minutes had elapsed after the optical oxygen sensor was started up.

Example 2
The present invention was carried out with an apparatus having the configuration shown in FIG. 1 equipped with the optical oxygen sensor of FIG.
The hydrogen peroxide sample solution used is the same as in Example 1.

Example 3
The present invention was implemented with an apparatus having the configuration shown in FIG. 2 equipped with the optical oxygen sensor of FIG.
The hydrogen peroxide sample solution used is the same as in Example 1.

Example 4
The present invention was carried out with an apparatus having the structure shown in FIG. 2 equipped with the optical oxygen sensor of FIG.
The hydrogen peroxide sample solution used is the same as in Example 1.

Example 5
The amount of hydrogen peroxide was measured under the same conditions as in Example 1 except that platinum nanocolloid (volume average particle size 3.5 nm) containing 5000 ppm of protective colloid-forming agent was used as the hydrogen peroxide decomposition means.

Comparative Example 1
The amount of hydrogen peroxide was measured under the same conditions as in Example 1 except that commercially available activated carbon was used as the hydrogen peroxide decomposition means.

Comparative Example 2
The amount of hydrogen peroxide was measured under the same conditions as in Example 1 except that palladium nanocolloid (volume average particle size 3.5 nm) was used as the hydrogen peroxide decomposition means.

Comparative Example 3
The amount of hydrogen peroxide was measured under the same conditions as in Example 1, except that 3600 made by Orbis Fair was used as the oxygen sensor and the measurement value after 10 minutes had elapsed after startup.

The above results are summarized in Table 1.

From Table 1, it can be seen that in Examples 1 to 5 of the present invention, the amount of hydrogen peroxide in ultrapure water can be quantified quickly and accurately by automatic analysis. In particular, when the results of Example 5 containing a protective colloid are compared with the results of Examples 1 to 4 that do not contain the protective colloid, it can be seen that it can be quantified more accurately if it is not included.
Compared with the examples, in Comparative Examples 1 to 3, the hydrogen peroxide decomposing means or the oxygen sensor is different from that of the present invention, so that the accuracy is inferior.

  From the above, in the present invention, a material having the highest hydrogen peroxide decomposition ability and free from impurities mixing and elution is used in an optimum form, and only oxygen generated by the decomposition of hydrogen peroxide is measured. Thus, it can be seen that a method for quantitatively determining hydrogen peroxide with improved measurement accuracy and measurement measure and an apparatus therefor are provided.

  It is used to control the concentration of hydrogen peroxide, which is used as a cleaning agent, bleach, and disinfectant in food, pharmaceuticals, paper pulp, fiber, and electronics industries. Further, in the field of water treatment, it is used for preventing adverse effects in the post-treatment process due to hydrogen peroxide, or for controlling the concentration of hydrogen peroxide in a system in which treated water is discharged out of the system as effluent water. In particular, the latter needs to be continuously and accurately grasped and managed, and can be suitably used in such a field.

The flowchart which shows one embodiment of this invention Flow chart showing another embodiment of the present invention The figure which shows one embodiment of the optical oxygen sensor used for this invention The figure which shows the other embodiment of the optical oxygen sensor used for this invention

Explanation of symbols

1, A, B, C Optical oxygen sensor 2 Hydrogen peroxide decomposition tank 3 Sample solution supply means 3a Pipe 3b Pipe 4 Outflow liquid supply means 5 Treatment liquid supply means 6 Sample solution discharge means 7 Hydrogen peroxide decomposition catalysts 8, 9 switching Valve 10 Dissolved oxygen measuring means 11 Excitation light source 12 Excitation filter 13 Bundle fiber 14 Oxygen sensing material 15 Receiving filter 16 Receiving device 17 Sample solution flow path 22, 28 Coupled lenses 23, 25, 27 Optical fiber 24 Optical demultiplexing multiplexer 26 Objective lens 29 Glass substrate

Claims (20)

  After the sample solution containing hydrogen peroxide is brought into contact with the hydrogen peroxide decomposition catalyst supporting platinum, the dissolved oxygen concentration in the treatment solution is measured by a photo-oxygen sensor, and the excess oxygen in the sample solution is measured from the dissolved oxygen concentration. A method for quantifying hydrogen peroxide, characterized in that the concentration of hydrogen oxide is quantified.   The dissolved oxygen concentration in the sample solution containing hydrogen peroxide and the dissolved oxygen concentration in the treatment solution after contacting the hydrogen peroxide decomposition catalyst supporting platinum with the sample solution were measured with an optical oxygen sensor. A method for quantifying hydrogen peroxide, comprising quantifying the hydrogen peroxide concentration in the sample solution from both dissolved oxygen concentrations obtained by the optical oxygen sensor.   After supplying the sample solution containing hydrogen peroxide to the optical oxygen sensor and measuring the dissolved oxygen concentration in the sample solution, the sample solution was brought into contact with the hydrogen peroxide decomposition catalyst supporting platinum by the switching means. Thereafter, the dissolved oxygen concentration in the processing solution is measured by the optical oxygen sensor, and the hydrogen peroxide concentration in the sample solution is quantified from both dissolved oxygen concentrations obtained by the optical oxygen sensor. Method for determining hydrogen peroxide.   The method for quantifying hydrogen peroxide according to claim 1, wherein after degassing the sample solution, the sample solution is brought into contact with the hydrogen peroxide decomposition catalyst.   The method for quantifying hydrogen peroxide according to claim 1, wherein the platinum contains 0 to 200 mass ppm of a protective colloid-forming agent.   The method for determining hydrogen peroxide according to claim 1, wherein the platinum is platinum nanoparticles.   The method for quantifying hydrogen peroxide according to claim 6, wherein the platinum nanoparticles are particles having a volume average particle diameter of 1 to 50 nm.   The method for quantifying hydrogen peroxide according to claim 1, wherein the hydrogen peroxide decomposition catalyst has platinum supported on a surface having an anion exchange group.   The method for quantifying hydrogen peroxide according to any one of claims 1 to 8, wherein the optical oxygen sensor is excited by visible light and detects dissolved oxygen by fluorescence or phosphorescence.   The method for quantifying hydrogen peroxide according to claim 1, wherein the sample solution containing hydrogen peroxide is continuously supplied and the hydrogen peroxide concentration is continuously quantified.   A sample solution supply means containing hydrogen peroxide, a hydrogen peroxide decomposition tank filled with a hydrogen peroxide decomposition catalyst supporting platinum, a dissolved oxygen measuring means by an optical oxygen sensor, and a dissolved oxygen measuring means by the optical oxygen sensor. A calculating means for calculating the hydrogen peroxide concentration in the sample solution from the measured dissolved oxygen concentration; a means for supplying the sample solution from the sample solution supplying means to the hydrogen peroxide decomposition tank; and the hydrogen peroxide decomposition tank And a means for supplying the processing solution from the above to the dissolved oxygen measuring means by the optical oxygen sensor.   Sample solution supply means containing hydrogen peroxide, dissolved oxygen measuring means A using an optical oxygen sensor, a hydrogen peroxide decomposition tank filled with a hydrogen peroxide decomposition catalyst carrying platinum, and dissolved oxygen measuring means B using an optical oxygen sensor And calculating means for calculating the hydrogen peroxide concentration in the sample solution from the dissolved oxygen concentrations measured by the dissolved oxygen measuring means A and B by the optical oxygen sensor, and the sample solution from the sample solution supply means. Means for supplying dissolved oxygen measuring means A by the optical oxygen sensor; means for supplying effluent from the dissolved oxygen measuring means A to the hydrogen peroxide decomposition tank; and treatment liquid from the hydrogen peroxide decomposition tank. Means for supplying the dissolved oxygen measuring means B by the optical oxygen sensor;   Hydrogen peroxide decomposition tank filled with hydrogen peroxide decomposition catalyst supporting platinum, dissolved oxygen measuring means using optical oxygen sensor, dissolved oxygen measuring means using optical oxygen sensor for sample solution containing hydrogen peroxide, or platinum A sample solution supply means having a switching means capable of being supplied to any one of the hydrogen peroxide decomposition tanks filled with the supported catalyst, and a processing solution from the hydrogen peroxide decomposition tank filled with the platinum-supported catalyst as the optical oxygen sensor. Supplying the dissolved oxygen measuring means by the optical oxygen sensor, the dissolved oxygen concentration measured by the dissolved oxygen measuring means by the optical oxygen sensor, and the treatment liquid from the hydrogen peroxide decomposition tank filled with the platinum-supported catalyst to the optical oxygen sensor. And a calculating means for calculating the hydrogen peroxide concentration in the sample solution from the dissolved oxygen concentration measured by the dissolved oxygen measuring means by .   The hydrogen peroxide concentration quantification apparatus according to any one of claims 11 to 13, wherein the hydrogen peroxide decomposition tank is equipped with a deaeration device.   The apparatus for quantitatively determining a hydrogen peroxide concentration according to claim 11, wherein the platinum contains 0 to 200 mass ppm of a protective colloid-forming agent.   The said platinum is a platinum nanoparticle, The quantitative determination apparatus of the hydrogen peroxide concentration in any one of Claims 11-15.   The apparatus for quantitatively determining a hydrogen peroxide concentration according to claim 16, wherein the platinum nanoparticles are particles having a volume average particle diameter of 1 to 50 nm.   The hydrogen peroxide concentration quantification apparatus according to any one of claims 11 to 17, wherein the hydrogen peroxide decomposition catalyst has platinum supported on a surface having an anion exchange group.   The hydrogen peroxide concentration quantification apparatus according to claim 11, wherein the optical oxygen sensor is excited by visible light and detects dissolved oxygen by fluorescence or phosphorescence.   The hydrogen peroxide concentration quantification apparatus according to claim 11, wherein the sample solution containing hydrogen peroxide is continuously supplied and the hydrogen peroxide concentration is continuously quantified.

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