Method for measuring total organic halogen content in water body

Abstract

The invention discloses a method for measuring the total organic halogen content in a water body, and relates to the technical field of water quality detection. The method comprises the following steps: acquiring a water sample to be detected; based on a solid-phase extraction column, organic halogen in a water sample to be detected is separated; obtaining halogenated organic matters in the solid-phase extraction column; preparing the halogenated organic matter into a mixed reaction solution; converting the organic halogen in the mixed reaction liquid into inorganic halogen by adopting an ultraviolet reduction device; based on the content of the inorganic halogen in the mixed reaction liquid, the total organic halogen content in the water sample to be detected is obtained. According to the application, the halogenated organic matters are extracted through the solid-phase extraction column, so that most halogenated organic matters in the water sample to be detected can be enriched. Compared with a high-temperature combustion method, the method provided by the invention has the advantages that halogen impurities are not introduced, and inorganic halogen loss is not caused, that is to say, the determination method provided by the invention is relatively small in test result deviation and relatively high in test accuracy rate.

Description

Technical Field

[0001] The present application relates to the technical field of water quality detection, and specifically to a method for determining the total organic halogen content in water. Background Art

[0002] Halogenated organic compounds (HOCs) refer to organic compounds containing halogens (fluorine, chlorine, bromine and iodine, etc.). Due to the complex molecular structure and variable degree of halogenation of halogenated organic compounds, it is difficult to accurately identify each type of halogenated organic compound. In the process of water quality testing, total organic halogens (TOX) are used as a comprehensive pollution assessment indicator to comprehensively reflect the content of halogenated organic compounds in water bodies. In other words, total organic halogens not only include identified organic halides, but also cover unknown organic halides, which helps to fully understand the organic halogen pollution of water bodies. However, total organic halogens in water bodies usually exist at trace levels (μg / L or ng / L), and other chemical components such as organic matter, inorganic halogens and suspended particles in water bodies will interfere with the determination of total organic halogens during the analysis process, which brings great challenges to the direct analysis of halogenated organic compounds.

[0003] There are many methods for determining the total organic halogen content in water in the prior art. For example, the most commonly used method is to first use activated carbon to adsorb organic halogens in water, then use high-temperature combustion to convert organic halogens in activated carbon into inorganic halogens, and finally combine microcoulometry or ion chromatography to obtain the total organic halogen value. However, the above methods have the following defects: first, activated carbon itself contains halogen impurities; second, activated carbon has poor adsorption for polar hydrophilic organic halogens; third, the hydrogen halide gas produced by high-temperature combustion is easily condensed in the exhaust pipe when it is cold, thereby causing inorganic halogen loss. These defects will lead to poor reproducibility of the test results of total organic halogens, that is, when multiple tests are carried out under the same conditions, the deviation of each test result is large. Summary of the invention

[0004] The purpose of the present application is to provide a method for determining the total organic halogen content in water, so as to solve the technical problem that the method for determining the total organic halogen content in water in the prior art has large errors.

[0005] To achieve the above objectives, this application provides the following technical solutions:

[0006] A method for determining the total organic halogen content in water, the method comprising:

[0007] Obtain water samples to be tested;

[0008] Based on solid phase extraction column, separate the organic halides in the water sample to be tested;

[0009] Obtain halogenated organics from solid phase extraction columns;

[0010] configuring the halogenated organic matter to form a mixed reaction liquid;

[0011] Using an ultraviolet reduction device to convert the organic halogen in the mixed reaction liquid into inorganic halogen;

[0012] Based on the content of inorganic halogen in the mixed reaction liquid, the total organic halogen content in the water sample to be tested is obtained.

[0013] As a specific solution in the technical solution of this application, the step of obtaining the water sample to be tested includes:

[0014] The water sample is filtered and collected by the first filter membrane to obtain a water sample free of impurities;

[0015] The pH value of the impurity-free water sample is adjusted using sulfuric acid solution and deionized water to obtain a water sample to be tested.

[0016] As a specific solution in the technical solution of the present application, the separation of organic halides in the water sample to be tested based on a solid phase extraction column includes:

[0017] sequentially activating the solid phase extraction column using a methanol solution and deionized water;

[0018] Passing the water sample to be tested through an activated solid phase extraction column;

[0019] The solid phase extraction column was eluted with deionized water.

[0020] As a specific solution in the technical solution of the present application, the solid phase extraction column includes a Bio-comma HLB column.

[0021] As a specific solution in the technical solution of the present application, the filler is a hydrophilic-lipophilic balanced filler; the method of obtaining the halogenated organic matter in the solid phase extraction column includes: drying the filler in the solid phase extraction column with protective gas and then taking it out.

[0022] As a specific solution in the technical solution of the present application, the step of configuring the halogenated organic matter to form a mixed reaction solution comprises:

[0023] Using sulfuric acid solution, sodium hydroxide solution, deionized water and reducing agent, alkaline water samples were obtained;

[0024] Taking the alkaline water sample of the same volume as the collected water sample and placing it in a reaction container; the reaction container is obtained in advance;

[0025] The filler is placed in the reaction container to form the mixed reaction liquid.

[0026] As a specific solution in the technical solution of this application, the ultraviolet reduction device includes:

[0027] Shaker;

[0028] A container clamp, arranged on the shaking table, for clamping a reaction container; the reaction container is used to store a mixed reaction liquid;

[0029] A lamp tube clamp, hinged to the shaking table, for clamping the ultraviolet lamp tube;

[0030] A light-shielding box cover is hinged to the rocking table; when in use, the light-shielding box cover is used to cover the container fixture and the lamp fixture to prevent ultraviolet light leakage.

[0031] As a specific solution in the technical solution of the present application, the ultraviolet lamp tube includes an ultraviolet mercury lamp and / or a vacuum ultraviolet mercury lamp.

[0032] As a specific solution in the technical solution of the present application, after the container clamp clamps the reaction container, the axis of the reaction container is parallel to the first direction; the shaking table can at least reciprocate the container clamp along the first direction.

[0033] As a specific solution in the technical solution of the present application, the total organic halogen content in the water sample to be tested is obtained based on the content of inorganic halogen in the mixed reaction solution, including:

[0034] filtering the mixed reaction liquid using a second filter membrane to obtain a filtrate;

[0035] Determining the inorganic halogen content in the filtrate;

[0036] Based on the inorganic halogen content in the filtrate, the total organic halogen content in the water sample to be tested is obtained.

[0037] Compared with the prior art, the beneficial effects of this application are:

[0038] The present application extracts halogenated organic matter through a solid phase extraction column, and can enrich most of the halogenated organic matter in the water sample to be tested. In addition, ultraviolet reduction is used to reduce the enriched organic halogen to inorganic halogen. Compared with the high-temperature combustion method, the present application does not introduce halogen impurities and does not cause inorganic halogen loss, that is, the test result deviation of the determination method of the present application is small, and the test accuracy is also high. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a schematic diagram of the structure of an ultraviolet reduction device proposed in an embodiment of the present application;

[0040] Figure 2This is a schematic flow chart of a method for determining the total organic halogen content in water proposed in an embodiment of the present application.

[0041] In the figure: 1. Light-shielding box cover; 2. Shaking table; 3. Lamp tube fixture; 4. Container fixture; 5. UV mercury lamp; 6. Vacuum UV mercury lamp; 7. Reaction container; 8. Digital display; 9. Power supply. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0043] Furthermore, it should be understood that for the sake of ease of description, the sizes of the various components shown in the drawings are not drawn according to actual proportions. For example, the thickness or width of certain layers may be exaggerated relative to other layers.

[0044] It should be noted that similar reference numerals and letters represent similar items in the following figures, and therefore, once an item is defined or described in one figure, it will not need to be further discussed and described in detail in the description of the subsequent figures.

[0045] If no specific experimental steps or conditions are specified in the examples, the experiments can be carried out according to the conventional steps or conditions described in the literature in the art. All reagents and raw materials used in the examples are commercially available products.

[0046] In order to solve the technical problem that the existing method for determining the total organic halogen content in water has large errors as mentioned in the background technology, the present application proposes an embodiment of a method for determining the total organic halogen content in water, such as Figure 2 As shown, the method includes steps S100 to S600.

[0047] Step S100: obtaining a water sample to be tested.

[0048] In the embodiments of the present application, the water sample to be tested can be obtained in any suitable manner, for example, a water sample can be directly collected from a water body and the collected water sample can be directly used as the water sample to be tested. That is, in the present embodiment, a water sample of a fixed volume (for example, 50 ml in the following text) can be collected from a water body as the water sample to be tested.

[0049] It should be noted that solid impurities may exist in general water bodies, and some solid impurities (for example, impurities containing halogens) will affect subsequent detection results. In order to avoid the influence of these solid impurities, in one embodiment of the present application, step S100, obtaining the water sample to be tested, includes step S110.

[0050] Step S110: Filter the collected water sample using the first filter membrane to obtain a water sample free of impurities.

[0051] It should be clear that, as can be seen from the foregoing, collecting water samples refers to water samples directly collected from a water body. In this embodiment, solid impurities in the collected water sample can be filtered out by filtering, thereby obtaining an impurity-free water sample without solid impurities. That is to say, in the embodiments of the present application, a fixed volume of water sample can be collected from the impurity-free water sample as the water sample to be tested.

[0052] In the embodiment of the present application, the first filter membrane can be any filter membrane that can filter solid impurities, for example, the first filter membrane can be an acetate filter membrane or a needle filter membrane, etc. If the first filter membrane is an acetate filter membrane with a pore size of 0.45 μm, the filter membrane can filter out larger particles of impurities and most bacteria and microorganisms, and the use cost of the filter membrane is relatively low.

[0053] In order to make it easier for the organic halide to be adsorbed and separated by the solid phase extraction column in step S200, in one embodiment of the present application, step S100, obtaining a water sample to be tested, may also include step S120.

[0054] Step S120: adjusting the pH value of the impurity-free water sample using sulfuric acid solution and deionized water to obtain a water sample to be tested.

[0055] In this embodiment, sulfuric acid solution can be added dropwise to the impurity-free water sample until the impurity-free water sample is acidic, thereby making the organic halide more easily adsorbed by the solid phase extraction column. In the embodiment of the present application, the pH value of the impurity-free water sample can be adjusted to be less than or equal to 2.0; of course, in other embodiments of the present application, the pH value of the impurity-free water sample can also be adjusted to other acidic values.

[0056] It should be clear that in the embodiments of the present application, the step numbers do not represent the order in which the steps are executed, but are only used to distinguish different steps. For example, in the embodiments of the present application, step S110 may be executed first, and then step S120; or step S120 may be executed first, and then step S110; when the collected water sample does not contain solid impurities, step S110 may not be executed, and only step S120 may be executed; when the impurity-free water sample itself is acidic, only step S110 may be executed, and step S120 may not be executed. In other words, in the embodiments of the present application, the execution order of the steps and whether to execute the current step may be adjusted according to actual conditions. In the embodiments of the present application, the same is true for other step numbers, which will not be listed and elaborated later.

[0057] Step S200: Separating organic halides in the water sample to be tested based on a solid phase extraction column.

[0058] It should be clear that in the embodiments of the present application, the solid phase extraction column can be any solid phase extraction column suitable for separating and extracting organic halogens in the water sample to be tested. For example, in one embodiment of the present application, the solid phase extraction column can be a solid phase extraction column with a hydrophilic-lipophilic balance filler; in another embodiment of the present application, the solid phase extraction column can be a Bio-comma HLB column. Specifically, the Bio-comma HLB column uses fillers with divinylbenzene structure and N-vinylpyrrolidone structure. The hydrophobic divinylbenzene structure can adsorb non-polar halogenated organics, while the hydrophilic N-vinylpyrrolidone structure can adsorb polar halogenated organics. In other words, the Bio-comma HLB column has good retention performance for all halogenated organics, which can improve the accuracy of subsequent detection.

[0059] In an embodiment of the present application, the organic halogen in the water sample to be tested can be separated by any suitable method based on a solid phase extraction column. For example, in an embodiment of the present application, step S200, based on a solid phase extraction column, separates the organic halogen in the water sample to be tested, including steps S210 to S230.

[0060] Step S210: activating the solid phase extraction column using methanol solution and deionized water in sequence.

[0061] It should be clear that in the embodiments of the present application, two column volumes of methanol solution and two column volumes of deionized water can be used in sequence to activate the solid phase extraction column. The purpose of activating the solid phase extraction column is to make the surface of the solid phase extraction column filler in the best chemical state, which is beneficial to the subsequent adsorption of halogenated organic matter. In other embodiments of the present application, other volumes of methanol solution and deionized water can also be selected to activate the solid phase extraction column. It is easy to understand that if the volume specification of the solid phase extraction column is 6ml, the volume of the two columns is 2*6ml=12ml; if the volume specification of the solid phase extraction column is 7ml, the volume of the two columns is 2*7ml=14ml... and so on.

[0062] Step S220: passing the water sample to be tested through the activated solid phase extraction column.

[0063] In an embodiment of the present application, 50 ml of the water sample to be tested can be passed through an activated solid phase extraction column. Alternatively, in an embodiment of the present application, the content of halogenated organic matter in the water sample to be tested can be estimated, and a suitable volume of the water sample to be tested can be selected to pass through the activated solid phase extraction column. For example, the content of halogenated organic matter in the water sample to be tested can be estimated by the turbidity of the water sample to be tested. If the turbidity of the water sample to be tested, or the chemical oxygen demand, or the mass concentration of carbon is higher, it is considered that the content of halogenated organic matter in the water sample to be tested is higher; if the turbidity of the water sample to be tested, or the chemical oxygen demand, or the mass concentration of carbon is lower, it is considered that the content of halogenated organic matter in the water sample to be tested is lower. If the estimated content of halogenated organic matter in the water sample to be tested is higher, the volume of the water sample to be tested passing through the activated solid phase extraction column can be reduced (for example, 30 ml or 40 ml, etc.); if the estimated content of halogenated organic matter in the water sample to be tested is lower, the volume of the water sample to be tested passing through the activated solid phase extraction column can be increased (for example, 60 ml or 70 ml, etc.).

[0064] Step S230: using deionized water to rinse the solid phase extraction column.

[0065] It should be clear that the purpose of eluting the solid phase extraction column with deionized water is to remove the salt in the solid phase extraction column, that is, to remove impurities with weak adsorption capacity in the solid phase extraction column, thereby reducing the interference of impurities on halogenated organic matter during the analysis process, thereby improving the accuracy of subsequent analysis.

[0066] Step S300: obtaining the halogenated organic matter in the solid phase extraction column.

[0067] It should be clear that in the embodiments of the present application, an elution solvent can be used to enrich the halogenated organic matter in the solid phase extraction column. Since the use of an elution solvent to enrich the halogenated organic matter in the solid phase extraction column is a mature technology, it will not be described in detail.

[0068] It should be noted that in application scenarios where the halogenated organic components in the water sample to be tested are relatively complex, it is difficult to enrich most of the halogenated organics in the solid phase extraction column by using the elution solvent. In order to obtain most of the halogenated organics in the solid phase extraction column, in an embodiment of the present application, the filler in the solid phase extraction column can be directly taken out, and the halogenated organics in the filler can be obtained in step S400. It is easy to understand that if the filler is directly taken out of the solid phase extraction column, a portion of the wet filler will adhere to the inner wall of the solid phase extraction column, thereby affecting subsequent test results. In order to improve the accuracy of subsequent test results, in one embodiment of the present application, step S300, obtaining the halogenated organics in the solid phase extraction column, includes step S310.

[0069] Step S310, the filler in the solid phase extraction column is blown dry with protective gas and then taken out.

[0070] In an embodiment of the present application, the protective gas may be nitrogen or an inert gas, etc. The protective gas can avoid chemical reactions with the halogenated organic matter in the filler, that is, it can avoid affecting the accuracy of subsequent test results. In this embodiment, after the filler is dried by the protective gas, the dry filler is not easy to adhere to the inner wall of the solid phase extraction column, that is, it is conducive to improving the accuracy of subsequent test results.

[0071] In an embodiment of the present application, an elution solvent can be used to wash out the halogenated organic matter in the filler. As can be seen from the foregoing, due to the complex molecular structure and variable degree of halogenation of the halogenated organic matter, the recovery rate of the halogenated organic matter in the filler by the elution solvent is low. If the recovery rate is lower, the accuracy of the subsequent detection results is lower. In order to make the halogenated organic matter have a higher recovery rate, in an embodiment of the present application, step S400 can be performed.

[0072] Step S400: preparing the halogenated organic matter into a mixed reaction solution.

[0073] It should be clear that in the embodiment of the present application, if the halogenated organic matter obtained by the elution solvent is used in step S300, the halogenated organic matter in the elution solvent is redissolved to obtain a mixed reaction liquid. If the halogenated organic matter obtained in step S300 is in the form of a dry filler, in order for the halogenated organic matter in the filler to be released in step S500, the halogenated ions can enter the mixed reaction liquid, thereby facilitating the filtration and separation of the filler and the halogenated ions. In the embodiment of the present application, step S400, the halogenated organic matter is configured to form a mixed reaction liquid, including steps S410 to S430.

[0074] Step S410: Obtain an alkaline water sample using sulfuric acid solution, sodium hydroxide solution, deionized water and a reducing agent.

[0075] In this embodiment, the alkaline water sample is an alkaline solution, that is, the pH value of the alkaline water sample is greater than 7.0. In this embodiment, the reducing agent includes sodium sulfite. It should be noted that the alkaline nature of the mixed reaction solution is conducive to the subsequent ultraviolet dehalogenation.

[0076] Step S420: Take an alkaline water sample of the same volume as the collected water sample and place it in the reaction container 7.

[0077] In this embodiment, the reaction container 7 is obtained in advance. In the embodiment of the present application, there is no limitation on the structure of the reaction container 7, which can be a test tube, or any container that can store alkaline water samples, such as a beaker or a measuring cup.

[0078] Step S430: placing the filler in the reaction container 7 to form a mixed reaction liquid.

[0079] In the embodiment of the present application, the reaction container 7 can be left to stand so that the alkaline water sample can fully react with the filler to form a mixed reaction liquid. It should be understood that since the mixed reaction liquid is alkaline, the halogenated organic matter in the mixed reaction liquid is easily reduced to inorganic halogen in step S500, which can improve the accuracy of subsequent detection results.

[0080] In other embodiments of the present application, in order to make the filler fully mixed with the alkaline water sample, and shorten the reaction time of forming a mixed reaction liquid. An oscillator can be used to oscillate the reaction vessel 7, thereby accelerating the reaction speed of the filler and the alkaline water sample. For example, in a specific embodiment of the present application, an oscillator can be used to oscillate the reaction vessel for ten minutes at an oscillation speed of 200r / min. Of course, in other embodiments of the present application, other suitable oscillation speeds and oscillation times can also be used, without any restriction, as long as the filler can be fully mixed with the alkaline water sample.

[0081] Step S500: using an ultraviolet reduction device to convert the organic halogen in the mixed reaction liquid into inorganic halogen.

[0082] It should be clear that in the embodiments of the present application, any device that can emit the required ultraviolet rays can be used as the ultraviolet reduction device, for example, the ultraviolet reduction device can be an ultraviolet light box. In order to improve the dehalogenation effect of the ultraviolet reduction device, in one embodiment of the present application, the ultraviolet reduction device can include a shaking table 2, a container fixture 4 and a lamp fixture 3. Specifically, Figure 1As shown, the container clamp 4 is arranged on the shaking table 2, and is used to clamp the reaction container 7. The reaction container 7 is used to store the mixed reaction liquid as mentioned above. The lamp tube clamp 3 is hinged to the shaking table 2, and is used to clamp the ultraviolet lamp. When in use, the lamp tube clamp 3 is buckled, and the ultraviolet lamp on the lamp tube clamp 3 is just opposite to the reaction container 7 on the container clamp 4, that is, the ultraviolet light emitted by the ultraviolet lamp can dehalogenate the halogenated organic matter in the reaction container 7. In this embodiment, the shaking table 2 can continuously shake the reaction container 7, so that the halogenated organic matter in the reaction container 7 can be fully in contact with the ultraviolet light, so as to ensure that the halogenated organic matter can fully absorb light and produce a dehalogenation reaction, that is, to enhance the dehalogenation effect.

[0083] In the embodiment of the present application, there is no restriction on the oscillation type of the shaking table 2, for example, the shaking table 2 can be reciprocating oscillation and / or clockwise cyclotron oscillation, etc. There is no restriction on the oscillation speed, for example, the oscillation speed can be greater than or equal to 200 r / min and less than or equal to 500 r / min, etc.

[0084] In order to make the filler and the alkaline water sample in the reaction container 7 fully mixed. In one embodiment of the present application, after the container clamp 4 clamps the reaction container 7, the axis of the reaction container 7 is parallel to the first direction; the shaking table 2 can at least reciprocate the container clamp 4 along the first direction. Since the direction of the reciprocating oscillation of the shaking table 2 is the same as the direction of the axis of the reaction container 7 after clamping, the principle of fluid mechanics can be fully utilized to make the filler and the water sample fully mixed.

[0085] In order to avoid the leakage of ultraviolet rays during use and reduce the utilization rate of ultraviolet rays, in one embodiment of the present application, the ultraviolet restoration device may further include a light shielding box cover 1. Figure 1 As shown, the light shielding box cover 1 is hinged to the shaking table 2. When in use, the light shielding box cover 1 is used to cover the container fixture 4 and the lamp fixture 3 to prevent ultraviolet light leakage. That is to say, in this embodiment, the light shielding box cover 1 is made of opaque material, which can not only enhance the reflection of ultraviolet light in the container to improve the utilization rate of ultraviolet light, but also prevent ultraviolet light leakage from causing harm to the experimenter.

[0086] In the embodiment of the present application, there is no restriction on the shape and structure of the reaction container 7. For example, as mentioned above, the reaction container 7 can be a test tube, a beaker or a measuring cup. In order to ensure that each part of the reaction container 7 can fully receive ultraviolet light, such as Figure 1 As shown, the reaction container 7 may be in a cylindrical shape. The material of the reaction container 7 may be a material that can transmit ultraviolet rays, for example, the reaction container 7 may be made of quartz. If the reaction container 7 is made of quartz, quartz has an excellent transmittance ratio to the wavelength of ultraviolet rays, which can improve the light absorption reaction efficiency of the halogenated organic matter.

[0087] In an embodiment of the present application, the ultraviolet lamp can be any lamp that can emit ultraviolet light. For example, the ultraviolet lamp can be an ultraviolet mercury lamp 5 and / or a vacuum ultraviolet mercury lamp 6. It should be noted that compared with ultraviolet irradiation, vacuum ultraviolet light can produce high-energy photons, so vacuum ultraviolet light can degrade halogenated organic matter better than ultraviolet light. In an embodiment of the present application, the output power of the ultraviolet mercury lamp 5 and the vacuum ultraviolet mercury lamp 6 can be selected according to demand, for example, the output power of the ultraviolet mercury lamp 5 and the vacuum ultraviolet mercury lamp 6 can both be 10W. Of course, in other embodiments of the present application, other output powers can also be selected, which will not be listed and described here.

[0088] In one embodiment of the present application, Figure 1 As shown, the number of ultraviolet mercury lamps 5 and vacuum ultraviolet mercury lamps 6 can be 6, and the ultraviolet mercury lamps 5 and vacuum ultraviolet mercury lamps 6 are alternately arranged. For ease of use, the ultraviolet mercury lamps 5 and vacuum ultraviolet mercury lamps 6 can be controlled by different switches. When in use, according to the characteristics of the halogenated organic matter, if the ultraviolet mercury lamp 5 is needed, the ultraviolet mercury lamp 5 can be turned on, and if the vacuum ultraviolet mercury lamp 6 is needed, the vacuum ultraviolet mercury lamp 6 can be turned on. That is to say, in this embodiment, there is no need to frequently disassemble the ultraviolet mercury lamps 5 and the vacuum ultraviolet mercury lamps 6.

[0089] In one embodiment of the present application, Figure 1 As shown, the ultraviolet reduction device may further include a digital display 8. The digital display 8 may be used to display parameters such as reaction time, oscillation speed, and oscillation type. It should be noted that in the field of oscillator technology, displaying parameters such as reaction time, oscillation speed, and oscillation type through a digital display 8 is a mature technology and will not be described in detail here.

[0090] In the embodiment of the present application, the ultraviolet restoration device can be connected to an external power source through a wire. For example, the ultraviolet restoration device can be connected to a two-phase or three-phase power supply network through a wire. Alternatively, in order to facilitate the use of the ultraviolet restoration device in the field, such as Figure 1 As shown, the ultraviolet reduction device can have its own power supply 9.

[0091] It should be noted that in the process of dehalogenating halogenated organic matter by ultraviolet light, it is necessary to prevent oxygen in the mixed reaction liquid from participating in the reaction, thereby affecting the subsequent detection results. In one embodiment of the present application, in step S500, before using an ultraviolet reduction device to convert the organic halogen in the mixed reaction liquid into an inorganic halogen, the method may also include step S440.

[0092] Step S440: Saturated nitrogen gas is introduced into the mixed reaction liquid for 30 minutes to remove excess oxygen in the mixed reaction liquid.

[0093] It should be noted that, since the excess oxygen in the mixed reaction liquid is removed by nitrogen, oxygen is not easy to participate in the reaction during the dehalogenation of halogenated organic matter, thereby improving the dehalogenation efficiency.

[0094] It should be noted that the output energy of the UV lamp is not stable at the beginning of its operation. In order to ensure that the UV lamp has stable output energy during use, that is, to ensure consistency in experimental results of different batches, in one embodiment of the present application, before step S500, using an ultraviolet reduction device to convert the organic halogen in the mixed reaction solution into an inorganic halogen, the method may further include step S450.

[0095] Step S450: Power on the ultraviolet lamp and preheat it for 30 minutes in advance.

[0096] It should be noted that, since the ultraviolet lamp (e.g., the ultraviolet mercury lamp 5 or the vacuum ultraviolet mercury lamp 6, etc.) is powered on in advance to preheat, the ultraviolet lamp can have a stable energy output during use. Since the ultraviolet lamp has a stable energy output, the detection conditions of different batches of experiments are the same, that is, the experimental results of different batches are consistent and can be compared or referenced with each other.

[0097] Step S600: based on the content of inorganic halogen in the mixed reaction liquid, the total organic halogen content in the water sample to be tested is obtained.

[0098] It should be clear that in the embodiments of the present application, the total organic halogen content in the water sample to be tested can be obtained based on the content of inorganic halogen in the mixed reaction liquid in any manner. For example, the content of inorganic halogen in the mixed reaction liquid can be obtained by microcoulometric method or ion chromatography, and then the total organic halogen content in the water sample to be tested can be obtained from the content of inorganic halogen in the mixed reaction liquid.

[0099] In a specific embodiment of the present application, step S600, based on the content of inorganic halogen in the mixed reaction liquid, obtains the total organic halogen content in the water sample to be tested, including steps S610 to S630.

[0100] Step S610: filtering the mixed reaction liquid using a second filter membrane to obtain a filtrate;

[0101] It should be clear that in this embodiment, the second filter membrane can be any filter membrane that can filter fillers. For example, the second filter membrane can be an acetate filter membrane or a needle filter membrane.

[0102] Step S620: using an ion chromatograph to measure the inorganic halogen content in the filtrate.

[0103] It should be noted that the use of an ion chromatograph to determine the inorganic halogen content in the filtrate is a mature technology and will not be described in detail here. Of course, in other embodiments of the present application, other methods may also be used to determine the inorganic halogen content in the filtrate. For example, titration, inductively coupled plasma mass spectrometry, and X-ray diffraction, etc., are not listed here one by one.

[0104] Step S630: Based on the inorganic halogen content in the filtrate, the total organic halogen content in the water sample to be tested is obtained.

[0105] As can be seen from the above, if the volume of the collected water sample is the same as the volume of the alkaline water sample, the inorganic halogen content in the filtrate can be directly used as the total organic halogen content in the water sample to be tested. If the volume of the collected water sample is different from the volume of the alkaline water sample, the total organic halogen content in the water sample to be tested can be converted from the inorganic halogen content in the filtrate.

[0106] In order to verify that the method proposed in the present application for determining the total organic halogen content in water has a high accuracy, the present application proposes several specific embodiments below.

[0107] It should be noted that the reagents and drugs involved in the following examples of this application include: 4-chlorophenol, 4-bromophenol, anhydrous sulfurous acid solution, deionized water, sulfuric acid solution, sodium hydroxide solution, methanol solution, 2-propanol solution, potassium bromide, potassium chloride, potassium hydroxide, etc. Among them, deionized water is produced from an ultrapure water machine (the resistivity of deionized water is 18.25MΩ·cm).

[0108] The instruments and equipment involved in the following embodiments of the present application include: solid phase extraction column, purchased from Thermo Fisher Scientific Inc. of the United States; ultrapure water machine, purchased from Merck; pH meter, purchased from Mettler Toledo Instruments Co., Ltd.; inductively coupled plasma mass spectrometer, model: Agilent8900I CP-MS, purchased from Agilent Technologies Co., Ltd.; ion chromatograph, model: DIONEX I CS-2100, purchased from Thermo Fisher Scientific Inc.

[0109] The analytical test conditions involved in the following examples of this application include:

[0110] 1. Inductively coupled plasma mass spectrometer analysis test conditions:

[0111] In Nogas detection mode, the spray gas, auxiliary gas and plasma gas were all argon, the spray gas was set to 0.95 mL / min, the auxiliary gas was set to 2 mL / min, the plasma gas was 16.75 mL / min, the ion lens voltage was set to 6.75 V, the RF power was set to 1500 W, the analog voltage was set to -1725 V, the pulse voltage was set to 950 V, the RPq parameter was set to 0.25, the retention time was set to 50 ms, and the integration time was set to 2000 ms.

[0112] 2. Ion chromatography analysis test conditions:

[0113] Chromatographic column: ThermoScientificDi onexI onPacAS19 column (5.0μm×4.0mm×250.0mm), with AG19 guard column;

[0114] Injection volume: 500 μL; injection mode: automatic injection; column temperature: 30 °C; flow rate: 0.5 mL / min;

[0115] Eluent: 12 mM potassium hydroxide solution; eluent flow rate: 0.5 mL / min isocratic elution.

[0116] Inhibition current: 21mA.

[0117] It should be noted that this embodiment is only an example of the method for determining the total organic halogen content in water proposed in the present application. It does not mean that the method for determining the total organic halogen content in water proposed in the present application is only applicable to the detection of 4-chlorophenol and 4-bromophenol, nor does it mean that the method for determining the total organic halogen content in water proposed in the present application can only be applied to the above-mentioned instruments or equipment, nor does it mean that the method for determining the total organic halogen content in water proposed in the present application can only use the above-mentioned analytical test conditions.

[0118] Embodiment 1:

[0119] In the embodiment of the present application, 4-bromophenol solution is used as the collected water sample, that is, the halogenated organic matter in this embodiment is 4-bromophenol solution.

[0120] First, weigh 173 mg of 4-bromophenol solid and dissolve it in deionized water, transfer it to a 100 mL volumetric flask, and dilute it with deionized water to obtain a 10 mM 4-bromophenol solution. Then transfer 500 μL of the 10 mM 4-bromophenol solution to a 50 mL volumetric flask, dilute it with deionized water, and obtain a 50 mL, 100 μM 4-bromophenol solution as the collected water sample. According to the above operation, configure the parallel sample.

[0121] Step S110: Filter the collected water sample using a 0.45 μm cellulose acetate filter membrane to obtain a water sample free of impurities.

[0122] Step S120: Acidify the impurity-free water sample using sulfuric acid solution and deionized water to obtain a water sample to be tested.

[0123] The specific steps are: adding sulfuric acid solution dropwise to the impurity-free water sample until the pH value of the impurity-free water sample is less than or equal to 2.0.

[0124] Step S210: Activate the Bio-comma HLB column using two column volumes of methanol solution and two column volumes of deionized water (the pH is adjusted to 2.0 using sulfuric acid solution) in sequence.

[0125] Step S220: The water sample to be tested is passed through the Bio-comma HLB column at a flow rate of 5 mL / min.

[0126] exist

[0127] Step S230: After all the water samples to be tested are enriched by the Bio-comma HLB column, two column volumes of deionized water with a pH value of 2.0 are used to wash the Bio-comma HLB column to remove salt.

[0128] Step S300: obtaining the halogenated organic matter in the solid phase extraction column.

[0129] Specifically, nitrogen was used to blow dry the filler in the Bio-comma HLB column, and the dried filler was recovered without using any elution solvent.

[0130] Step S400: preparing the halogenated organic matter into a mixed reaction solution.

[0131] In this example, sodium sulfite solution is used as a reducing agent. 630 mg of anhydrous sodium sulfite solution solid is weighed and dissolved in deionized water, transferred into a 50 mL volumetric flask, and fixed to volume with deionized water to obtain a sodium sulfite solution with a concentration of 100 mM.

[0132] Step S410: 49.5 mL of deionized water is measured, 500 μL of 100 mM sodium sulfite solution is added, and then the pH value of the sodium sulfite solution is adjusted to 9.0 using sulfuric acid solution and sodium hydroxide solution to obtain an alkaline water sample.

[0133] Step S420: Take 50 ml of alkaline water sample into the reaction container 7.

[0134] Step S430: Move the dry filler to the reaction container 7 and mix well to obtain SO3 2-50 mL of mixed reaction solution with a concentration of 1 mM. The reaction container 7 containing the mixed reaction solution is placed on the shaker 2 and fixed by the test tube clamp 4. The shaker 2 is started through the digital display 8 for ten minutes to fully mix the filler and the alkaline water sample, and the rotation speed is 200 r / min.

[0135] Step S440: Saturated nitrogen gas is introduced into the mixed reaction liquid for 30 minutes to remove excess oxygen in the mixed reaction liquid.

[0136] Step S450: preheat the ultraviolet lamp for 30 minutes in advance to maintain a stable energy output of the lamp.

[0137] Step S500: Turn on the ultraviolet reduction device to convert the organic bromine in the reaction container 7 into inorganic bromine. After reacting for 240 minutes, take a sample for subsequent determination. The sampling volume is 1 mL each time and stored in an environment of 4° C. for subsequent determination. It should be noted that in other embodiments of the present application, the reaction time can be time, for example, 180 minutes or 300 minutes.

[0138] In this embodiment, the ultraviolet reduction device uses a vacuum ultraviolet mercury lamp 6 to emit ultraviolet rays, and the wavelengths of the ultraviolet rays emitted are 185nm and 254nm.

[0139] Step S610: Use a 0.22 μm needle filter membrane to remove fillers in the sample to be measured to obtain a filtrate.

[0140] Step S620: using an ion chromatograph to measure the inorganic halogen content (ie, inorganic bromine content) in the filtrate.

[0141] In this embodiment, the total halogen content (i.e., the total bromine content) in the parallel samples needs to be determined by an inductively coupled plasma mass spectrometer. Further, the conversion rate of organic halogen to inorganic halogen can be obtained based on the total halogen content and the inorganic halogen content. Specifically, the calculation formula of the conversion rate is as follows:

[0142]

[0143] Wherein, C represents the conversion rate; C3 represents the inorganic halogen content in the filtrate; and C4 represents the total halogen content in the parallel sample.

[0144] Step S630: Based on the inorganic bromine content in the filtrate, the total organic bromine content in the water sample to be tested is obtained.

[0145] Embodiment 2:

[0146] In this embodiment, except that an ultraviolet mercury lamp 5 (ultraviolet wavelength is 254 nm) is used in step S500, the remaining experimental steps are the same as those in embodiment 1.

[0147] Embodiment 3:

[0148] In this embodiment, 4-chlorophenol solution is used as the collected water sample, that is, the halogenated organic matter in this embodiment is 4-chlorophenol, and the remaining experimental steps are the same as those in Example 1.

[0149] Embodiment 4:

[0150] In this embodiment, except that an ultraviolet mercury lamp 5 (ultraviolet wavelength is 254 nm) is used in step S500, the remaining experimental steps are the same as those in embodiment 3.

[0151] Embodiment 5:

[0152] In this embodiment, step S300 uses two column volumes of 2-propanol solution to elute the halogenated organic matter enriched in the Bio-comma HLB column, and the elution solvent is stored in a 50mL Corning tube, and then the elution solvent in the Corning tube is blown dry using a nitrogen blower. Step S400 uses 50ml of alkaline water sample to redissolve the halogenated organic matter in the Corning tube to obtain a mixed reaction solution. The remaining experimental steps are the same as those in Example 3.

[0153] Embodiment 6:

[0154] In this embodiment, except that an ultraviolet mercury lamp 5 (ultraviolet wavelength is 254 nm) is used in step S500, the remaining experimental steps are the same as those in embodiment 5.

[0155] Embodiment 7:

[0156] In this embodiment, 4-bromophenol solution is used as the collected water sample, that is, the halogenated organic matter in this embodiment is 4-bromophenol, and the remaining experimental steps are the same as those in Example 5.

[0157] Embodiment 8:

[0158] In this embodiment, except that an ultraviolet mercury lamp 5 (ultraviolet wavelength is 254 nm) is used in step S500, the remaining experimental steps are the same as those in embodiment 7.

[0159] Comparative Example 1:

[0160] In this comparative example, except that the water sample collection is the same as in Example 1, the testing method adopts the high-temperature combustion method proposed in the background technology (the reference standard number is: HJ / T 83-2001, entitled: Determination of adsorbable organic halogen (AOX) in water by ion chromatography, the method disclosed in this industry standard).

[0161] Comparative Example 2:

[0162] In this comparative example, 4-chlorophenol solution was used as the collected water sample, that is, the halogenated organic matter in this comparative example was 4-chlorophenol, and the remaining experimental steps were the same as those of comparative example 1.

[0163] It should be clear that in order to prove the effectiveness of the method proposed in the embodiments of the present application (that is, the deviation of the test results of multiple experiments is relatively small compared with the prior art), in the present application, 6 experiments were conducted on Comparative Example 1, Comparative Example 2 and Examples 1 to 8, and the results of the 6 experiments were averaged to obtain the final measurement results, and the standard deviation of the 6 experimental results was calculated to determine the deviation of the multiple test results. Specifically, the experimental results are shown in Table 1.

[0164] Table 1

[0165]

[0166] As can be seen from Table 1, the test accuracy of the test method proposed in the embodiment of the present application is comparable to that of the prior art, but the standard deviation of its test results is significantly better than that of the prior art.

[0167] It should be clear that the present application extracts halogenated organic matter through a solid phase extraction column, which can enrich most of the halogenated organic matter in the water sample to be tested. And ultraviolet reduction is used to reduce the enriched organic halogen to inorganic halogen. Compared with the high-temperature combustion method, the present application does not introduce halogen impurities and does not cause inorganic halogen loss, that is, the test result deviation of the determination method of the present application is small, and the test accuracy is also high.

[0168] Finally, it should be noted that, in the present disclosure, if any, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0169] Although the embodiments of the present application have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for determining the total organic halogen content in water, characterized in that: The method comprises: Obtain water samples to be tested; Based on solid phase extraction column, separate the organic halides in the water sample to be tested; Obtain halogenated organics from solid phase extraction columns; configuring the halogenated organic matter to form a mixed reaction liquid; Using an ultraviolet reduction device to convert the organic halogen in the mixed reaction liquid into inorganic halogen; Based on the content of inorganic halogen in the mixed reaction liquid, the total organic halogen content in the water sample to be tested is obtained.

2. The method for determining the total organic halogen content in water according to claim 1, characterized in that: The step of obtaining the water sample to be tested comprises: The water sample is filtered and collected by the first filter membrane to obtain a water sample free of impurities; The pH value of the impurity-free water sample is adjusted using sulfuric acid solution and deionized water to obtain a water sample to be tested.

3. The method for determining the total organic halogen content in water according to claim 1, characterized in that: The method for separating organic halogens in a water sample to be tested based on a solid phase extraction column comprises: sequentially activating the solid phase extraction column using a methanol solution and deionized water; Passing the water sample to be tested through an activated solid phase extraction column; The solid phase extraction column was eluted with deionized water.

4. The method for determining the total organic halogen content in water according to claim 1, characterized in that: The solid phase extraction column comprises a Bio-comma HLB column.

5. The method for determining the total organic halogen content in water according to claim 1, characterized in that: The filler is a hydrophilic-lipophilic balanced filler; the method of obtaining the halogenated organic matter in the solid phase extraction column comprises: drying the filler in the solid phase extraction column with protective gas and then taking it out.

6. The method for determining the total organic halogen content in water according to claim 2, characterized in that: The step of configuring the halogenated organic matter to form a mixed reaction solution comprises: Using sulfuric acid solution, sodium hydroxide solution, deionized water and reducing agent, alkaline water samples were obtained; Taking the alkaline water sample of the same volume as the collected water sample and placing it in a reaction container (7); the reaction container (7) is obtained in advance; The filler is placed in the reaction container (7) to form the mixed reaction liquid.

7. The method for determining the total organic halogen content in water according to any one of claims 1 to 6, characterized in that: The ultraviolet reduction device comprises: Shaker (2); A container clamp (4) is arranged on the shaking table (2) and is used to clamp a reaction container (7); the reaction container (7) is used to store a mixed reaction liquid; A lamp tube clamp (3) is hinged to the shaking table (2) and is used to clamp the ultraviolet lamp tube; The light-shielding box cover (1) is hinged to the rocking bed (2); when in use, the light-shielding box cover (1) is used to cover the container fixture (4) and the lamp fixture (3) to prevent ultraviolet light leakage.

8. The method for determining the total organic halogen content in water according to claim 7, characterized in that: The ultraviolet lamp tube comprises an ultraviolet mercury lamp (5) and / or a vacuum ultraviolet mercury lamp (6).

9. The method for determining the total organic halogen content in water according to claim 7, characterized in that: After the container clamp (4) clamps the reaction container (7), the axis of the reaction container (7) is parallel to the first direction; and the shaking table (2) is capable of reciprocatingly oscillating the container clamp (4) at least along the first direction.

10. The method for determining the total organic halogen content in water according to claim 7, characterized in that: The method of obtaining the total organic halogen content in the water sample to be tested based on the content of inorganic halogen in the mixed reaction solution comprises: filtering the mixed reaction liquid using a second filter membrane to obtain a filtrate; Determining the inorganic halogen content in the filtrate; Based on the inorganic halogen content in the filtrate, the total organic halogen content in the water sample to be tested is obtained.

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