Method for extracting organohalogen compounds

Abstract

To extract organic halide compounds from a solution that contains organic halide compounds suppressing missed extractions by a simple operation.SOLUTION: The present invention uses an extraction column 1 comprising a first column 10 equipped with a treatment layer 100 and a second column 20 removably connected to the first column 10 and filled with a capture layer 200 that includes granular zirconia oxide. After a solution that contains an organic halide compound and a contaminant is added to the treatment layer 100, an aliphatic hydrocarbon solvent is supplied and passed through the treatment layer 100 and the capture layer 200 in the order stated. In this case, the contaminant in the solution is treated in the treatment layer 100 and the organic halide compound in the solution is dissolved in the aliphatic hydrocarbon solvent and passes through the treatment layer 100, then captured by the capture layer 200. When, after passage through the aliphatic hydrocarbon solvent, an extraction solvent is supplied to the second column 20 separated from the first column 10 and passed through the capture layer 200, this extraction solvent becomes an extract with the organic halide compound extracted from the capture layer 200.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for extracting organohalogen compounds, in particular to a method for extracting organohalogen compounds from a solution containing them. [Background technology]

[0002] Sediment, soil, incineration ash from incineration facilities, food, biological samples such as blood and breast milk, environmental water such as seawater, river water, lake water, and groundwater, industrial wastewater, air, exhaust gas from incineration facilities, and electrical insulating oil discarded from electrical equipment are required to be evaluated for contamination by organohalogen compounds that are of concern for their toxicity to living organisms. For example, for dioxins, which are known as environmental pollutants with high toxicity to living organisms, the Special Measures Law for Countermeasures against Dioxins (Law No. 105 of 1999) prescribes environmental standards and sets emission control standards for each specific facility, and requires periodic quantitative evaluation. In addition, the European Union (EU) food regulation standard (COMMISSION REGULATION (EU) No 1259 / 2011) designates dioxins and certain polychlorinated biphenyls that do not belong to the dioxin group as organohalogen compounds to be regulated for foods such as beef, pork, animal fats and oils, eggs, and vegetable oils such as olive oil, and sets regulation values ​​for these and requires quantitative evaluation. In addition, Method 1668C, April 2010, prescribed by the United States Environmental Protection Agency (EPA), requires the quantitative evaluation of polychlorinated biphenyls in water, soil, sediment, and individual organisms and tissues, and prescribes the evaluation method.

[0003] In assessing contamination by organohalogen compounds, the organohalogen compounds are usually extracted from the sample to be evaluated using a solvent such as an aliphatic hydrocarbon solvent, such as hexane, or an aromatic hydrocarbon solvent, such as toluene, and the solution of organohalogen compounds obtained by this extraction is then analyzed using highly sensitive analytical equipment such as gas chromatography / mass spectrometry (GC / MS) or gas chromatography / electron capture detection (GC / ECD).

[0004] When extracting organic halogen compounds from a sample to be evaluated for analysis, it is preferable to use a solvent that can efficiently extract the organic halogen compounds from the sample to be evaluated, but the extract obtained by using such a solvent may be difficult to apply to an analytical instrument as it is. In this case, it is preferable to replace the solvent of the extract with another solvent that is easily applicable to an analytical instrument, but this replacement process must be simple to operate and prevent the loss of organic halogen compounds that are likely to occur during the process.

[0005] In addition, when organic halogen compounds are extracted from a sample to be evaluated for analysis, various organic compounds are usually extracted as impurities along with the organic halogen compounds. If the extracted solution is used as an analytical sample as is, the impurities may contaminate the analytical equipment, and the impurities may affect the analysis results of the organic halogen compounds. Therefore, the extract of organic halogen compounds from a sample to be evaluated usually requires pretreatment to remove the impurities, but this pretreatment also requires removing the impurities while preventing the organic halogen compounds from being overlooked. For example, polychlorinated biphenyls (hereinafter sometimes referred to as PCBs) are a general term for biphenyls in which hydrogen atoms are replaced by chlorine atoms, and there are 10 types of congeners ranging from monochlorobiphenyl to decachlorobiphenyl based on the number of chlorines replaced, and there are 209 types of congeners based on the number and position of chlorine replacement. Therefore, in order to analyze PCBs extracted from samples to be evaluated with high accuracy, a pretreatment method is required that does not impair the recovery rate of each PCB congener, that is, a highly accurate pretreatment method that can remove impurities so that the recovery rate remains within the officially acceptable range.

[0006] As one of the highly accurate pretreatment methods, Non-Patent Document 1 describes a pretreatment method for a hexane solution in which PCBs have been extracted from bottom sediments. In this pretreatment method, the sample hexane solution is repeatedly treated with sulfuric acid, and the treated hexane solution is washed with a saturated sodium chloride solution and concentrated. The concentrated hexane solution is then further treated with a silica gel column containing sodium sulfate, and PCBs are extracted from the silica gel column using hexane. Although this pretreatment method can effectively remove impurities without compromising the recovery rate of each congener of PCBs, it takes a long time to complete because most of the steps are done manually, and the number of samples that can be treated within a certain time is limited. [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] August 2012, Ministry of the Environment, Water and Air Environment Bureau, Bottom Sediment Survey Methods (II.6.4) Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention is intended to extract an organohalogen compound from a solution containing the compound by a simple procedure while minimizing loss of the compound. [Means for solving the problem]

[0009] The present invention relates to a method for extracting organic halogen compounds from a solution containing the organic halogen compounds. The extraction method includes the steps of adding the solution to a trapping layer capable of trapping the organic halogen compounds, and extracting the organic halogen compounds from the solution to which the solution has been added. capture layer The method includes the steps of supplying and passing an aliphatic hydrocarbon solvent through the trapping bed, supplying and passing an extraction solvent for organic halogen compounds through the trapping bed through which the aliphatic hydrocarbon solvent has passed, and retaining the extraction solvent that has passed through the trapping bed. The trapping bed used here contains granular zirconium oxide.

[0010] In this extraction method, when an aliphatic hydrocarbon solvent is supplied to the trapping layer to which the solution has been added, the aliphatic hydrocarbon solvent flows through the trapping layer while dissolving the organic halogen compounds in the solution. At this time, the organic halogen compounds dissolved in the aliphatic hydrocarbon solvent develop and are captured in the trapping layer. Then, when an extraction solvent is supplied to the trapping layer, the extraction solvent flows through the trapping layer while dissolving the organic halogen compounds captured in the trapping layer. Therefore, when the extraction solvent that has passed through the trapping layer is secured, an extract of the organic halogen compounds, i.e., an extraction solvent solution, is obtained.

[0011] Another aspect of the present invention relates to a method for extracting an organic halogen compound from a solution containing the organic halogen compound and impurities. This extraction method includes the steps of adding the solution to a treatment layer capable of treating the impurities, supplying an aliphatic hydrocarbon solvent to the treatment layer to which the solution has been added and passing it through, supplying the aliphatic hydrocarbon solvent that has passed through the treatment layer to a trapping layer capable of trapping the organic halogen compound and passing it through, supplying an extraction solvent for the organic halogen compound to the trapping layer through which the aliphatic hydrocarbon solvent has passed and passing it through, and securing the extraction solvent that has passed through the trapping layer. The trapping layer used here contains granular zirconium oxide.

[0012] In this extraction method, when an aliphatic hydrocarbon solvent is supplied to the treatment layer to which the solution has been added, the organic halogen compounds and impurities in the solution dissolve in the aliphatic hydrocarbon solvent and pass through the treatment layer. At this time, the impurities in the solution are treated. When the aliphatic hydrocarbon solvent that has passed through the treatment layer is subsequently supplied to and passed through the capture layer, the organic halogen compounds in the aliphatic hydrocarbon solvent from the treatment layer are captured in the capture layer, and the aliphatic hydrocarbon solvent passes through the capture layer with the organic halogen compounds removed. When an extraction solvent is supplied to this capture layer, the extraction solvent passes through the capture layer while extracting the organic halogen compounds captured in the capture layer. Therefore, when the extraction solvent from the capture layer is secured, an extract of the organic halogen compounds contained in the solution is obtained.

[0013] Solutions to which this extraction method can be applied include, for example, solutions in which organic halogen compounds have been extracted using a solvent from a material layer at the bottom of the hydrosphere or on the land surface, food, biological samples, environmental water, wastewater, electrical insulating oil, incineration ash, or a collector that has captured gaseous contents.

[0014] According to yet another aspect, the present invention relates to a column for trapping organic halogen compounds contained in a solution, the column being packed with a trapping layer containing granular zirconium oxide.

[0015] According to yet another aspect, the present invention relates to a column for extracting an organohalogen compound from a solution containing the organohalogen compound and impurities. The column includes a first column packed with a treatment layer capable of treating the impurities, and a second column packed with a capture layer capable of capturing the organohalogen compound and detachably connected to the first column. The capture layer contains granular zirconium oxide.

[0016] According to yet another aspect, the present invention relates to a trapping material for organic halogen compounds, the trapping material including granular zirconium oxide. Effect of the Invention

[0017] The method for extracting organic halogen compounds according to the present invention uses a capture layer containing granular zirconium oxide, and therefore can extract organic halogen compounds from a solution containing organic halogen compounds, particularly a solution containing organic halogen compounds and impurities, with a simple operation and with minimal loss of the compounds.

[0018] The column for trapping organic halogen compounds and the column for extracting organic halogen compounds according to the present invention have a trapping layer containing granular zirconium oxide, and therefore can be used in the method for extracting organic halogen compounds according to the present invention.

[0019] The organic halogen compound capture material according to the present invention contains granular zirconium oxide, and therefore can capture the organic halogen compounds contained in the solution while preventing them from being overtaken. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a schematic diagram of one embodiment of an extraction column that can be used in the method for extracting organic halogen compounds according to the present invention. [Diagram 2] FIG. 2 is a schematic diagram of another form of extraction column that can be used in the method for extracting organic halogen compounds according to the present invention. [Diagram 3] FIG. 2 is a schematic diagram of still another form of extraction column that can be used in the method for extracting organic halogen compounds according to the present invention. [Figure 4] FIG. 1 is a schematic diagram of one embodiment of a column for trapping organic halogen compounds that can be used in the method for extracting organic halogen compounds according to the present invention. [Diagram 5] Graph showing the results of Example 1. [Figure 6] Graph showing the results of Example 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The method for extracting an organohalogen compound according to the present invention relates to a method for extracting an organohalogen compound from a solution containing the organohalogen compound.

[0022] The organohalogen compounds to be extracted include, for example, dioxins (polychlorinated dibenzoparadioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs)), polyhalogenated biphenyls such as polychlorinated biphenyls (PCBs) and polybrominated biphenyls, polybrominated diphenyl ethers (PBDEs), and chlordanes used as insecticides, as well as various organohalogen compounds subject to the Stockholm Convention on POPs. The solution containing such an organic halogen compound and subject to the extraction method of the present invention, i.e., the organic halogen compound-containing solution, is usually a solution obtained by extracting an organic halogen compound using a solvent from a substance that requires evaluation of the state of contamination by an organic halogen compound, such as a material layer at the bottom of the hydrosphere or on the land surface, such as bottom sediment or soil, food such as agricultural crops, meat, and seafood, body fluids such as breast milk and blood, biological samples such as organs and tissues, environmental water such as river water, lake water, and groundwater, wastewater such as industrial wastewater and domestic wastewater, electrical insulating oil, incineration ash produced in an incineration facility, or a collector such as a filter that collects contents in gas such as the environmental air or exhaust gas discharged from an incineration facility. The solvent for extraction to obtain this solution is not particularly limited as long as it is capable of dissolving the organic halogen compound, and is usually an organic solvent. As the organic solvent, for example, an aliphatic hydrocarbon solvent, in particular, a nonpolar aliphatic hydrocarbon solvent having 5 to 10 carbon atoms such as n-hexane, isooctane, nonane, or decane, an aromatic hydrocarbon solvent such as toluene or xylene, or a polar organic solvent such as acetone, diethyl ether, or dichloromethane can be used.

[0023] An organic halogen compound-containing solution typically contains various impurities derived from the above-mentioned evaluation object that require evaluation of the contamination status due to organic halogen compounds, mainly various organic substances other than organic halogen compounds, for example aromatic compounds such as polycyclic aromatic hydrocarbons and aliphatic hydrocarbons such as paraffins, together with the organic halogen compounds.

[0024] <Form 1> An example (embodiment 1) of an extraction column used to carry out the method for extracting organic halogen compounds according to the present invention will be described with reference to Fig. 1. In the figure, the extraction column 1 mainly comprises a first column 10 and a second column 20 (one embodiment of the column for capturing organic halogen compounds according to the present invention) connected to the first column 10 so as to form a continuous flow path system, and is installed in an upright state.

[0025] The first column 10 is a cylindrical member with both ends open, and is made of a material having at least solvent resistance, chemical resistance, and heat resistance, such as glass, resin, or metal having these properties. The first column 10 has a screw part (not shown) for connecting to the second column 20 on the outer circumferential surface of the lower end part in the figure, and is filled with a treatment layer 100 inside. The treatment layer 100 is for treating impurities contained in the organic halogen compound-containing solution, for example, for decomposing the impurities or capturing the impurities or their decomposition products, and is formed by laminating a retention layer 110 and a sulfate silica gel layer 120 in this order downward inside the first column 10.

[0026] The retaining layer 110 is a layer that has liquid permeability and is permeable to an organic halogen compound-containing solution, and is formed by filling a material that is inactive against organic halogen compounds. Examples of materials that form the retaining layer 110 include granular silica gel, activated silica gel in which the activity of granular silica gel is increased by heating, granular or amorphous silicon dioxide, cotton-like glass fiber, cotton-like quartz glass, granular Florisil (magnesium silicate), granular activated clay, diatomaceous earth such as Celite, and resin materials such as polyethylene resin, polypropylene resin, polytetrafluoroethylene resin, polyvinylidene fluoride resin, or perfluoroalkoxyalkane resin, which are molded into a particle shape or the like. Two or more of these materials may be used in combination. In this case, the materials may be mixed and used, or may be arranged in multiple layers in the vertical direction. A preferable material is silica gel, particularly granular silica gel with a particle size of about 40 to 210 μm, because it is inexpensive and easy to fill the first column 10.

[0027] The packing density of the above-mentioned materials in the support layer 110 is usually 0.1 to 2.5 g / cm 3 It is preferable to set the density to 0.2 to 1 g / cm 3 It is more preferable to set the packing density to 0.1 g / cm. 3 If the packing density is less than 2.5 g / cm, when an organic halogen compound-containing solution is added to the treatment layer 100, the added organic halogen compound-containing solution is difficult to retain in the retention layer 110, and may permeate the retention layer 110 and migrate to the sulfate silica gel layer 120 within a short period of time. 3 If it exceeds this value, when an aliphatic hydrocarbon solvent is supplied to the treatment layer 100 as described below, the aliphatic hydrocarbon solvent may have difficulty passing through the retention layer 110 .

[0028] The sulfated silica gel layer 120 is formed by filling with sulfated silica gel. The sulfated silica gel used here is prepared by uniformly adding concentrated sulfuric acid to the surface of granular silica gel (usually activated silica gel whose activity has been increased by heating) having a particle size of about 40 to 210 μm. The amount of concentrated sulfuric acid added to the silica gel is usually preferably set to 10 to 60% of the mass of the silica gel.

[0029] The packing density of the silica gel sulfate in the silica gel sulfate layer 120 is usually 0.2 to 2.0 g / cm 3 It is preferable to set the density to 0.5 to 1.0 g / cm 3 It is more preferable to set the packing density to 0.2 g / cm. 3 If the packing density is less than 2.0 g / cm, impurities other than the organohalogen compounds contained in the solution containing the organohalogen compounds are less likely to be captured by the sulfuric acid silica gel layer 120, and separation of the organohalogen compounds and the impurities in the solution containing the organohalogen compounds may be difficult. 3 If it exceeds this value, when an aliphatic hydrocarbon solvent is supplied to the treatment layer 100 as described below, the aliphatic hydrocarbon solvent may have difficulty passing through the sulfuric acid silica gel layer 120 .

[0030] In the treatment layer 100, the filling amounts of the retention layer 110 and the sulfuric acid silica gel layer 120 depend on the amount (sample amount) of the organic halogen compound-containing solution applied to the extraction column 1. For example, when the sample amount is 2 mL or less, the filling amount of the retention layer 110 is usually preferably set to 0.2 to 3 mL, more preferably set to 0.5 to 1.5 mL. If the filling amount is less than 0.2 mL, when the organic halogen compound-containing solution is added to the treatment layer 100, the added organic halogen compound-containing solution is not easily retained in the retention layer 110, and may permeate the retention layer 110 and migrate to the sulfuric acid silica gel layer 120 within a short period of time. Conversely, if the filling amount exceeds 3 mL, when an aliphatic hydrocarbon solvent is supplied to the treatment layer 100, the aliphatic hydrocarbon solvent may not easily pass through the retention layer 110. Similarly, when the sample amount is 2 mL or less, the filling amount of the sulfuric acid silica gel forming the sulfuric acid silica gel layer 120 is usually preferably set to 1 to 10 mL, more preferably set to 3 to 6 mL. If the filling amount is less than 1 mL, impurities other than the organohalogen compounds contained in the organohalogen compound-containing solution are less likely to be captured in the sulfuric acid silica gel layer 120, which may make it difficult to separate the organohalogen compounds from the impurities in the organohalogen compound-containing solution. Conversely, if the filling amount exceeds 10 mL, when an aliphatic hydrocarbon solvent is supplied to the treatment layer 100, the aliphatic hydrocarbon solvent may be less likely to pass through the sulfuric acid silica gel layer 120.

[0031] The second column 20 is a cylindrical member with both ends open, and is made of the same material as the first column 10. An attachment section 21 into which the lower end portion of the first column 10 in the figure can be inserted is formed on the upper end side of the second column 20 in the figure. A threaded portion (not shown) corresponding to the threaded portion at the lower end portion of the first column 10 in the figure is formed on the inner circumferential surface of the attachment section 21.

[0032] The inside of the second column 20 is filled with a trapping layer 200. The trapping layer 200 contains a trapping material for organic halogen compounds, and this trapping material contains granular zirconium oxide.

[0033] Zirconium oxide is a type of metal that is also called zirconium dioxide (ZrO 2 ) and has the ability to adsorb organic halogen compounds. The zirconium oxide used here may be one that has been calcined under a stream of an inert gas such as nitrogen or air to enhance its adsorption activity for organic halogen compounds, or may be stabilized zirconia or partially stabilized zirconia that has been enhanced in stability against temperature changes by adding a rare earth oxide such as calcium oxide, magnesium oxide, or yttrium oxide. The particle size of the zirconium oxide is usually preferably 5 to 500 μm, and particularly preferably 10 to 300 μm.

[0034] The capture material may contain, together with powdered zirconium oxide, other materials capable of capturing organic halogen compounds, for example, carbon-based adsorbents such as activated carbon and graphite, and aluminum oxide, or may contain adsorbents such as silica gel, mesoporous silica gel, magnesium silicate, and zeolite. Two or more of the other materials may be used in combination.

[0035] The packing density of the capture material in the capture layer 200 is usually 0.1 to 2.5 g / cm 3 It is preferable to set the density to 0.5 to 1.5 g / cm 3 It is more preferable to set the packing density to 0.1 g / cm. 3 If the packing density is less than 2.5 g / cm3, it may be difficult to recover the organic halogen compounds contained in the solution containing the organic halogen compounds while suppressing their loss. 3 If the concentration exceeds this range, there is a possibility that the recovery of the organic halogen compounds will be insufficient or that the pressure drop will be high when the organic halogen compounds are extracted from the capture layer 200 with an extraction solvent described below.

[0036] In the trapping layer 200, the amount of the trapping material depends on the amount of the organic halogen compound-containing solution (sample amount) applied to the extraction column 1. For example, when the sample amount is 2 mL or less, the amount of the trapping material is usually preferably set to 0.2 to 3.0 mL, more preferably 0.3 to 1.5 mL. If the amount is less than 0.2 mL, some of the organic halogen compounds contained in the organic halogen compound-containing solution may not be captured in the trapping layer 200, and the recovery rate of the organic halogen compounds may be impaired. Conversely, if the amount is more than 3.0 mL, the amount of extraction solvent required to extract the organic halogen compounds captured in the trapping layer 200 becomes large, which is uneconomical.

[0037] The first column 10 is liquid-tightly and detachably connected to the second column 20 by attaching a screw portion provided on the outer periphery of its lower end to a screw portion provided on the inner periphery of the mounting portion 21 of the second column 20.

[0038] The size of the extraction column 1 can be appropriately set according to the amount of the solution containing an organic halogen compound to be treated. For example, when the amount of the solution containing an organic halogen compound is about 1 to 20 mL, the first column 10 preferably has an inner diameter of 10 to 20 mm and a length of the portion capable of packing the treatment layer 100 of about 30 to 110 mm, and the second column 20 preferably has an inner diameter of 2.0 to 10 mm and a length of the portion capable of packing the capture layer 200 of about 10 to 50 mm.

[0039] Next, a method for extracting organic halogen compounds from an organic halogen compound-containing solution using the above-mentioned extraction column 1 will be described. In this extraction method, the extraction column 1 is installed in an upright position as shown in Fig. 1, and an organic halogen compound-containing solution is added onto the treatment layer 100 in the first column 10 from the opening at the top. The added organic halogen compound-containing solution gradually permeates into the retention layer 110 and is retained within the retention layer 110.

[0040] In this step, the sample may be diluted by adding a hydrocarbon solvent capable of dissolving the organic halogen compound and miscible with an aliphatic hydrocarbon solvent described below to the processing layer 100 while adding the organic halogen compound-containing solution to the processing layer 100. The hydrocarbon solvent may be added immediately after the organic halogen compound-containing solution is added to the processing layer 100, or may be added to the organic halogen compound-containing solution in advance.

[0041] Next, the aliphatic hydrocarbon solvent is supplied into the first column 10 from the opening at the top of the first column 10. The aliphatic hydrocarbon solvent supplied into the first column 10 permeates into the treatment layer 100 while accumulating in the upper part of the first column 10, and passes through the retention layer 110 and the sulfuric acid silica gel layer 120 in this order while dissolving the organic halogen compound-containing solution retained in the retention layer 110. The aliphatic hydrocarbon solvent thus passed through the treatment layer 100 flows into the second column 20 from the opening at the bottom of the first column 10. In this process, some of the impurities other than the organic halogen compounds contained in the aliphatic hydrocarbon solvent that has dissolved the organic halogen compound-containing solution are captured in the sulfuric acid silica gel layer 120 when passing through the sulfuric acid silica gel layer 120.

[0042] The aliphatic hydrocarbon solvent that has flowed into the second column 20 passes through the trapping layer 200 and is discharged from the opening at the bottom. At this time, the organohalogen compounds dissolved in the aliphatic hydrocarbon solvent from the first column 10 are selectively captured in the trapping layer 200. Here, since the organohalogen compounds are easily captured in the trapping layer 200, they are mainly captured near the upper part of the trapping layer 200. In addition, impurities that have not been captured in the treatment layer 100 and have flowed into the second column 20 together with the organohalogen compounds pass through the trapping layer 200 together with the aliphatic hydrocarbon solvent and are discharged from the second column 20.

[0043] The aliphatic hydrocarbon solvent supplied to the first column 10 in the above-mentioned process is capable of dissolving the organic halogen compounds in the organic halogen compound-containing solution, and is usually an aliphatic saturated hydrocarbon solvent having 5 to 8 carbon atoms, such as n-pentane, n-hexane, n-heptane, n-octane, isooctane, and cyclohexane. In particular, n-hexane is preferred. When the size of the extraction column 1 is as described above, the total amount of the aliphatic hydrocarbon solvent supplied to the first column 10 is usually preferably set to 10 to 120 mL. In addition, the supply rate of the aliphatic hydrocarbon solvent is usually preferably set to 0.2 to 5.0 mL / min.

[0044] In the above steps, the temperature of the treatment bed 100 is set to less than 35°C, preferably 30°C or less, more preferably 28°C or less. Therefore, when the above steps are performed in a high temperature environment and the temperature of the treatment bed 100 is 35°C or more, the temperature of the treatment bed 100 is controlled to less than 35°C using a cooling material or a cooling device. When the temperature of the treatment bed 100 is 35°C or more, some of the organic halogen compounds, especially organic halogen compounds with a small number of chlorines (e.g., low-chlorine PCBs), are easily decomposed or adsorbed in the sulfuric acid silica gel layer 120, and the extraction rate (recovery rate) of some of the organic halogen compounds may decrease. The lower limit of the temperature of the treatment bed 100 is not particularly limited as long as it is within a temperature range in which the aliphatic hydrocarbon solvent can flow smoothly, but it is usually preferable to set it to about 10°C or more.

[0045] Next, the first column 10 and the second column 20 are separated, and the second column 20 is turned upside down. Then, while the entire trapping layer 200 of the second column 20 is heated to about 35 to 90°C, an inert gas such as nitrogen gas or air is supplied into the second column 20 from the opening that has moved to the upper end. As a result, the solvent such as the aliphatic hydrocarbon solvent remaining in the second column 20 is discharged together with the inert gas from the opening that has moved to the lower end of the second column 20. As a result, the solvent such as the aliphatic hydrocarbon solvent is removed from the trapping layer 200, and the trapping layer 200 is dried.

[0046] Next, an extraction solvent capable of dissolving the organic halogen compounds is supplied from the opening at the top end of the second column 20, which is upright while still upside down. The supplied extraction solvent gradually permeates into the trapping layer 200 due to its own weight. The extraction solvent that has permeated into the trapping layer 200 passes through the trapping layer 200 and flows out from the opening moving to the bottom end side of the second column 20. At this time, the extraction solvent dissolves the organic halogen compounds captured in the trapping layer 200 and flows out from the opening together with the organic halogen compounds. Therefore, by securing the extraction solvent that flows out from the opening, an extraction solvent solution of the organic halogen compounds, i.e., an extract of the desired organic halogen compounds, is obtained.

[0047] Here, the organic halogen compounds are mainly captured near the bottom of the capture layer 200 of the inverted second column 20, so that substantially the entire amount of the organic halogen compounds captured in the capture layer 200 is dissolved in the extraction solvent, mainly the initial part, flowing out of the second column 20. Therefore, the target extract of the organic halogen compounds can be obtained simply by securing the extraction solvent, mainly the initial part, flowing out of the second column 20, so that the amount of the extract can be kept small enough to be easily used in the analysis operation described below. In addition, the extract of the organic halogen compounds obtained here is obtained by removing the aliphatic hydrocarbon solvent from the capture layer 200 and then supplying the extraction solvent to the capture layer 200, so that it can be of high purity with little contamination by the aliphatic hydrocarbon solvent and impurities dissolved therein.

[0048] According to the extraction method of the present embodiment, the above-mentioned extract can be obtained in a short time, usually about 0.5 to 1 hour, from the start of the process.

[0049] When extracting organic halogen compounds from the trapping layer 200, it is preferable to supply the extraction solvent while heating the entire trapping layer 200. The heating temperature of the trapping layer 200 is usually set to at least 35°C, and more preferably to 60°C or higher. The upper limit of the heating temperature is not particularly limited, but is usually about 90°C. When the trapping layer 200 is heated during extraction, the organic halogen compounds trapped in the trapping layer 200 are easily extracted in their entirety with a smaller amount of extraction solvent, and the amount of the organic halogen compound extraction liquid can be controlled to a smaller amount that is easy to use in the analysis operation described below.

[0050] The extraction solvent for extracting the organic halogen compounds from the trapping layer 200 can be selected according to the analysis method of the organic halogen compounds. When gas chromatography is used as the analysis method, a hydrophobic solvent capable of dissolving the organic halogen compounds is used as the extraction solvent. Examples of such hydrophobic solvents include toluene, a mixed solvent of toluene and an aliphatic hydrocarbon solvent (e.g., n-pentane, n-hexane, n-heptane, n-octane, isooctane, cyclohexane, etc.), and a mixed solvent of an organic chlorine-based solvent (e.g., dichloromethane, trichloromethane, tetrachloromethane, etc.) and an aliphatic hydrocarbon solvent (e.g., n-pentane, n-hexane, n-heptane, n-octane, isooctane, cyclohexane, etc.). Among these, toluene is preferred because it can extract the organic halogen compounds from the trapping layer 200 with a smaller amount of use.

[0051] When a hydrophobic solvent is used as the extraction solvent, the extract can be used as it is or, if necessary, after being appropriately concentrated, as an analytical sample by gas chromatography. Gas chromatography can be performed using a gas chromatograph equipped with various detectors, but gas chromatography mass spectrometry (GC / MS including GC / MS / MS) or gas chromatography electron capture detection (GC / ECD) is usually preferred, as they have good sensitivity to organic halogen compounds. In particular, the GC / MS method allows the organic halogen compounds contained in the extract to be quantified in units of isomers or homologues, and more knowledge can be obtained from the analysis results.

[0052] When a bioassay method is used as the analytical method, a hydrophilic solvent capable of dissolving the organic halogen compounds is used as the extraction solvent, such as dimethyl sulfoxide (DMSO) or methanol.

[0053] When a hydrophilic solvent is used as the extraction solvent, the extract can be used as it is as an analytical sample in a bioassay method such as an immunoassay method or an ELISA method.

[0054] The above-mentioned extraction method uses a trapping material containing granular zirconium oxide, which has excellent selective trapping ability for organic halogen compounds, in the trapping layer 200, and therefore can extract organic halogen compounds from a solution containing organic halogen compounds with a simple operation with little loss of the compounds. For example, when the solution containing organic halogen compounds contains PCBs as organic halogen compounds, each of various PCBs of various congeners with chlorine numbers ranging from 1 to 10 can be extracted with a high recovery rate. In addition, when the solution containing organic halogen compounds contains dioxins (generally a general term for polychlorinated dibenzoparadioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (DL-PCBs). DL-PCBs are PCBs among the 209 types of polychlorinated biphenyls (PCBs) that exhibit similar toxicity to PCDDs and PCDFs, and include non-ortho-PCBs and mono-ortho-PCBs)) and polychlorinated biphenyls not classified as dioxins (non-DL-PCBs), it is possible to extract PCDDs and PCDFs as well as a wide range of polychlorinated biphenyls with chlorine numbers from 1 to 10 together with a high recovery rate.

[0055] When extracts containing various dioxins and non-DL-PCBs are analyzed using a high-resolution gas chromatograph mass spectrometer (high-resolution GC / MS), it is known that mono-ortho-PCBs affect the quantitative analysis results of PCDDs and PCDFs, and that PCDDs and PCDFs affect the quantitative analysis results of mono-ortho-PCBs, and the analytical results may lack reliability. However, the reliability of the analytical results can be improved by using a gas chromatograph triple quadrupole mass spectrometer (GC-MS / MS).

[0056] <Form 2> Another embodiment of the extraction column used for carrying out the method for extracting organic halogen compounds according to the present invention will be described with reference to Fig. 2. The extraction column 2 of this embodiment is the same as the extraction column 1 of embodiment 1, except that the treatment layer 100 of the first column 10 and the shape of the second column 20 are changed.

[0057] The treatment layer 100 used in the first column 10 of this embodiment is for treating impurities contained in the organic halogen compound-containing solution, as in the case of embodiment 1, and is formed by laminating a silver nitrate silica gel layer 210 and a sulfate silica gel layer 220 in this order downward within the first column 10.

[0058] The silver nitrate silica gel layer 210 is a layer formed of silver nitrate silica gel. The silver nitrate silica gel used here is prepared by uniformly adding an aqueous solution of silver nitrate to the surface of granular silica gel (usually activated silica gel whose activity is increased by heating) having a particle size of about 40 to 210 μm, and then removing moisture by heating under reduced pressure. The amount of silver nitrate supported on the silica gel is usually preferably set to 5 to 20% based on the mass of the silica gel. If the amount supported is less than 5%, the effect of treating impurities in the silver nitrate silica gel layer 210 may decrease. On the other hand, if it exceeds 20%, the amount of silver ions in the silver nitrate silica gel layer 210 increases, so that organic halogen compounds are easily captured, and it may be difficult to recover part of the organic halogen compounds in the extraction of the organic halogen compounds.

[0059] The moisture content of the silver nitrate silica gel layer 210 is generally set to 2-10% based on the mass of the silica gel, and more preferably 3.5-5%. If the moisture content is 2% or less, the activity of silver ions in the silver nitrate silica gel layer 210 increases, so that organic halogen compounds are more likely to be captured, and it may become difficult to recover some of the organic halogen compounds during extraction of the organic halogen compounds. Conversely, if the moisture content exceeds 10%, the effect of treating impurities in the silver nitrate silica gel layer 210 may decrease.

[0060] The packing density of the silver nitrate silica gel in the silver nitrate silica gel layer 210 is not particularly limited, but is usually 0.3 to 0.8 g / cm. 3 It is preferable to set the density to 0.4 to 0.7 g / cm 3 It is more preferable to set the density to 0.3 g / cm3 If the density is less than 0.8 g / cm3, the efficiency of processing impurities may decrease. 3 If it exceeds this value, the aliphatic hydrocarbon solvent will have difficulty passing through the treatment layer 100 .

[0061] The silica gel sulfate layer 220 is similar to the silica gel sulfate layer 120 used in the first embodiment.

[0062] The second column 20 used in this embodiment is a cylindrical member with both ends open, and is made of the same material as that used in embodiment 1. An attachment section 21 into which the lower end portion of the first column 10 in the figure can be inserted is formed at the upper end side of the second column 20 in the figure. A screw section (not shown) is formed on the inner peripheral surface of the attachment section 21. The second column 20 also has a branch passage 22 below the attachment section 21, the tip of which is open.

[0063] The inside of the second column 20 is filled with a trapping layer 200 below the branch passage 22. The trapping layer 200 is the same as that used in the first embodiment. The inner diameter of the second column 20 and the length of the portion that can be filled with the trapping layer 200 are set to be the same as those of the second column 20 in the first embodiment.

[0064] When extracting an organic halogen compound from a solution containing an organic halogen compound using the extraction column 2 of this embodiment, the extraction column 2 is installed in an upright position as shown in Fig. 2, the opening at the tip of the branch path 22 is closed, and the solution containing an organic halogen compound is added from the opening at the top end onto the treatment layer 100 in the first column 10. At this time, it is preferable to heat a part of the treatment layer 100, i.e., the entire silver nitrate silica gel layer 210 and the upper part of the sulfate silica gel layer 220.

[0065] The added organic halogen compound-containing solution penetrates the upper part of the silver nitrate silica gel layer 210 and is heated together with the above-mentioned part of the treatment layer 100. The heating temperature of the treatment layer 100 is set to 35°C or higher, preferably 50°C or higher, and more preferably 60°C or higher. This heating causes some of the impurities other than the organic halogen compounds contained in the organic halogen compound-containing solution to react with the treatment layer 100 and decompose. If the heating temperature is less than 35°C, the reaction between the impurities and the treatment layer 100 will not proceed easily, and some of the impurities may easily remain in the extract of the organic halogen compounds. The upper limit of the heating temperature is not particularly limited, but it is usually preferable that it is equal to or lower than the boiling temperature of the organic halogen compound-containing solution from the viewpoint of safety.

[0066] Next, after a predetermined time, for example, 10 to 60 minutes, has elapsed since the start of heating, an aliphatic hydrocarbon solvent similar to that listed in embodiment 1 is supplied to the treatment layer 100 in the first column 10 from the opening at the top end and passed through. At this time, the heating of the treatment layer 100 may be maintained or stopped. The aliphatic hydrocarbon solvent supplied to the treatment layer 100 dissolves the organic halogen compounds contained in the organic halogen compound-containing solution that has permeated the treatment layer 100, the decomposition products of the impurities, and the impurities that remain undecomposed, and passes through the treatment layer 100. At this time, a part of the decomposition products and impurities is adsorbed to the silver nitrate silica gel layer 210 and the sulfuric acid silica gel layer 220. In addition, the aliphatic hydrocarbon solvent passing through the treatment layer 100 is naturally cooled when passing through the non-heated portion, i.e., the lower part of the sulfuric acid silica gel layer 220.

[0067] The aliphatic hydrocarbon solvent that has passed through the treatment bed 100 flows from the first column 10 to the second column 20, passes through the trapping bed 200, and flows out from the opening at the lower end of the second column 20 and is discarded. At this time, the organic halogen compounds contained in the aliphatic hydrocarbon solvent from the treatment bed 100 are trapped in the trapping bed 200 and separated from the aliphatic hydrocarbon solvent.

[0068] After the aliphatic hydrocarbon solvent passes through the trapping layer 200, the opening at the top of the first column 10 is airtightly closed and the end of the branch path 22 is opened. Then, as in the case of the first embodiment, an inert gas or the like is supplied from the opening at the bottom of the second column 20 and discharged from the branch path 22 to dry the trapping layer 200, and then an extraction solvent for the organic halogen compound is supplied from the opening at the bottom of the second column 20 and passed through the trapping layer 200. The extraction solvent used here is the same as that listed in the first embodiment. The extraction solvent supplied to the trapping layer 200 extracts the organic halogen compound captured in the trapping layer 200, flows to the branch path 22, and is discharged from the branch path 22. By securing the extraction solvent discharged from the branch path 22 in this way, i.e., the extraction solvent that has passed through the trapping layer 200, an extract of the organic halogen compound is obtained.

[0069] <Form 3> With reference to Fig. 3, still another embodiment of the extraction column used to carry out the method for extracting organic halogen compounds according to the present invention will be described. The extraction column 3 of this embodiment is obtained by changing the second column 20 in the extraction column 2 of the embodiment 2, and is suitable for use in cases where an organic halogen compound-containing solution contains many kinds of organic halogen compounds and these organic halogen compounds need to be extracted while being separated. For example, when the organic halogen compounds contained in the organic halogen compound-containing solution contain dioxins and non-DL-PCBs, if these organic halogen compounds are extracted together using the extraction column 1 of the embodiment 1 or the extraction column 2 of the embodiment 2, when the extract is analyzed by high-resolution GC / MS, as described above with respect to the embodiment 1, mono-ortho PCBs affect the quantitative analysis results of PCDDs and PCDFs, and PCDDs and PCDFs affect the quantitative analysis results of mono-ortho PCBs. Therefore, when extracting these organohalogen compounds from a solution containing dioxins and non-DL-PCBs and analyzing the extract using a high-resolution GC / MS, it is advantageous in terms of improving analytical accuracy if the extract can be separated into an extract containing mono-ortho-PCBs and an extract containing PCDDs and PCDFs.

[0070] The second column 20 used in this embodiment is basically a cylindrical member with both ends open, made of the same material as that used in embodiment 2, and is set to be longer than the second column 20 in embodiment 2. An attachment section 21 into which the lower end portion of the first column 10 in the figure can be inserted is formed at the upper end side of the second column 20 in the figure. A threaded portion (not shown) is formed on the inner peripheral surface of the attachment section 21. The second column 20 also has two branch passages with open ends below the attachment section 21, i.e., a first branch passage 23 and a second branch passage 24 provided at a distance from each other.

[0071] The inside of the second column 20 is filled with a trapping layer 200 below the second branch 24, and a preceding trapping layer 250 is filled between the first branch 23 and the second branch 24. The trapping layer 200 is a layer similar to the trapping layer 200 of form 2. The preceding trapping layer 250 is formed using a carbon-based material or activated magnesium silicate. As the carbon-based material, for example, granular activated carbon or graphite, or a carbon-containing silica gel such as activated carbon-containing silica gel or graphite-containing silica gel described in International Publication WO2014 / 192055 can be used. The activated magnesium silicate is a magnesium silicate that has been heat-treated to remove moisture and increase its activity, and is described in JP 2020-115111 A. As the carbon-based material, a mixture of activated magnesium silicate and graphite as described in JP 2020-115111 A can also be used.

[0072] It is preferable that the second column 20 has an inner diameter of 3 to 10 mm, a length of the portion capable of being filled with the trapping layer 200 of about 20 to 50 mm, and a length of the portion capable of being filled with the preceding trapping layer 250 of about 20 to 50 mm.

[0073] Next, a method for extracting an organic halogen compound from an organic halogen compound-containing solution using the above-mentioned extraction column 3 will be described. In this extraction method, an organic halogen compound-containing solution is added to the treatment layer 100 and heat-treated in the same manner as in the method for extracting an organic halogen compound using the extraction column 2 of form 2, and then an aliphatic hydrocarbon solvent is supplied to the treatment layer 100 and passed through it. Then, the aliphatic hydrocarbon solvent that passes through the treatment layer 100 and flows from the first column 10 to the second column 20 is passed through the preceding capture layer 250 and the capture layer 200 in this order, and is discharged from the opening at the lower end of the second column 20 and discarded. At this time, the impurities contained in the organic halogen compound-containing solution are mainly treated in the treatment layer 100 as in the case of form 2, and the impurities remaining in the aliphatic hydrocarbon solvent that passed through the treatment layer 100 pass through the preceding capture layer 250 and the capture layer 200 together with the aliphatic hydrocarbon solvent and are discarded, and the remainder is captured in the preceding capture layer 250 and the capture layer 200. On the other hand, the organic halogen compounds contained in the aliphatic hydrocarbon solvent from the treatment layer 100 are captured in each of the preceding capture layer 250 and the capture layer 200, and separated from the aliphatic hydrocarbon solvent. The aliphatic hydrocarbon solvent used here is the same as that described in the first embodiment.

[0074] Here, when the organic halogen compound-containing solution is a solution containing dioxins and non-DL-PCBs, the non-ortho PCBs, PCDDs, and PCDFs among the dioxins are captured in the preceding capture layer 250, and the mono-ortho PCBs and non-DL-PCBs among the dioxins are captured in the capture layer 200. That is, the dioxins and non-DL-PCBs contained in the organic halogen compound-containing solution are fractionated in the second column 20 into a dioxin group including non-ortho PCBs, PCDDs, and PCDFs captured by the preceding capture layer 250, and a PCB group including mono-ortho PCBs and non-DL-PCBs captured by the capture layer 200.

[0075] After the aliphatic hydrocarbon solvent has passed through the trapping layer 200, the opening at the top of the first column 10 and the opening at the second branch path 24 are airtightly closed. Then, as in the case of the first embodiment, an inert gas or the like is supplied from the opening at the bottom of the second column 20 and discharged from the first branch path 23 to dry the trapping layer 200 and the preceding trapping layer 250. Thereafter, the opening at the top of the first column 10 and the opening at the first branch path 23 are airtightly closed, the opening at the second branch path 24 is opened, and an extraction solvent for the organic halogen compound is supplied from the opening at the bottom of the second column 20 and passed through the trapping layer 200. The extraction solvent used here is the same as that listed in the first embodiment.

[0076] The extraction solvent supplied to the trapping layer 200 extracts the organic halogen compounds trapped in the trapping layer 200, flows to the second branch 24, and is discharged from the second branch 24. By securing the extraction solvent discharged from the second branch 24 in this manner, an extract of the organic halogen compounds trapped in the trapping layer 200, i.e., an extract of the above-mentioned PCB group, is obtained. Here, since the trapping layer 200 can capture various congeners of polychlorinated biphenyls with chlorine numbers ranging from 1 to 10, the extract of the above-mentioned PCB group obtained in this process is less likely to miss out on each congener of polychlorinated biphenyls.

[0077] Next, the opening at the top of the first column 10 and the opening of the second branch path 24 are airtightly closed, while the opening of the first branch path 23 is opened, and an extraction solvent for the organic halogen compound is supplied from the opening at the bottom of the second column 20 and passed through the trapping layer 200 and the preceding trapping layer 250 in that order. The extraction solvent used here can be selected from those listed in the first embodiment, and may be the same as or different from the one used for extraction from the trapping layer 200.

[0078] The extraction solvent supplied to the preceding trapping layer 250 through the trapping layer 200 extracts the organohalogen compounds trapped in the preceding trapping layer 250, flows to the first branched path 23, and is discharged from the first branched path 23. By securing the extraction solvent discharged from the first branched path 23 in this manner, an extract of the organohalogen compounds trapped in the preceding trapping layer 250, i.e., the above-mentioned dioxin group, is obtained.

[0079] In this embodiment, an extract containing the dioxins and an extract containing the PCBs can be obtained separately. By analyzing each extract using high-resolution GC / MS, the components contained in the dioxins and the components contained in the PCBs can be analyzed with high accuracy.

[0080] <Form 4> The second column 20 used in the extraction column 1 of the first embodiment uses a trapping material containing powdered zirconium oxide, which has excellent selective trapping ability for organic halogen compounds, and therefore can be used to purify the organic halogen compounds contained in the organic halogen compound-containing solution or to transfer them to another solvent in the state separated from the first column 10. In this case, the organic halogen compound-containing solution is added to the trapping layer 200 of the second column 20. The organic halogen compounds in the added organic halogen compound-containing solution are trapped in the trapping layer 200, while the solvent of the solution passes through the trapping layer 200. If the organic halogen compound-containing solution contains impurities, particularly hydrocarbon compound-based impurities, together with the organic halogen compounds, the impurities pass through the trapping layer 200 together with the solvent without being trapped in the trapping layer 200, and are separated from the organic halogen compounds. The trapping layer 200 after the addition of the organic halogen compound-containing solution may be appropriately dried by blowing an inert gas such as nitrogen through it or heating it. Next, when an extraction solvent is supplied to the capture layer 200 and passed through it, the organic halogen compounds captured in the capture layer 200 are extracted by the extraction solvent. Therefore, when the extraction solvent that has passed through the capture layer 200 is secured, an extraction solvent solution containing the extracted organic halogen compounds is obtained. When the organic halogen compound-containing solution added to the capture layer 200 contains impurities, the resulting extraction solvent solution is a purified solution from which the impurities have been removed. In addition, if an extraction solvent different from the solvent of the organic halogen compound-containing solution is used as the extraction solvent, the resulting extraction solvent solution is one in which the organic halogen compounds in the organic halogen compound-containing solution have been transferred to the extraction solvent.

[0081] When supplying the extraction solvent, the second column 20 may be turned upside down to supply the extraction solvent as in the case of embodiment 1, or the extraction solvent may be supplied from the opening on the side where the organic halogen compound-containing solution was added without turning upside down. In addition, when the purpose is to purify the organic halogen compound-containing solution, the same solvent as that of the organic halogen compound-containing solution may be used as the extraction solvent.

[0082] The organic halogen compound-containing solution to be purified or dissolved is usually an organic solvent solution using various organic solvents, but it may also be an aqueous solution as long as the capture layer 200 to which the solution has been added is dried.

[0083] Furthermore, the second column 20 used for the purpose of purification or solvent transfer may be of a simple shape without the mounting portion 21, as shown in FIG.

[0084] <Modification> In each of the first to third forms, the treatment layer 100 of the first column 10 can be changed to various other forms for the purpose of treating impurities contained in the organic halogen compound-containing solution. For example, the treatment layer 100 used in the second and third forms may be used in the first form, and the treatment layer 100 used in the first form may be used in the second and third forms. In addition, the treatment layer 100 in the first form may be one in which the retention layer 110 is omitted, and the treatment layer 100 in the second and third forms may be one in which the sulfate silica gel layer 220 is omitted. Furthermore, in the treatment layer 100 in the second and third forms, the silver nitrate silica gel layer 210 may be replaced with a layer formed using the mixed nitrate silica gel described in JP 2015-21868 A.

[0085] In the treatment layer 100 of the second and third embodiments, the order of the silver nitrate silica gel layer 210 and the sulfuric acid silica gel layer 220 can be reversed. In this case, impurities contained in the organic halogen compound-containing solution are mainly decomposed in the sulfuric acid silica gel layer 220, and the decomposition products and some of the impurities are mainly captured in the silver nitrate silica gel layer 210. In this modification, a carrier layer having permanganate fixed thereto may be disposed between the sulfuric acid silica gel layer 220 and the silver nitrate silica gel layer 210. By disposing such a carrier layer, the SOx gas generated when the impurities are decomposed in the sulfuric acid silica gel layer 220 can be consumed in the carrier layer, thereby improving the safety of the operation of extracting the organic halogen compound from the organic halogen compound-containing solution.

[0086] The carrier layer used here is a layer made of a granular carrier, for example, aluminum oxide, silica gel (usually activated silica gel whose activity is increased by heating), crystalline aluminosilicate such as zeolite, or a mixture of any combination thereof, to which a permanganate is fixed. The permanganate is not particularly limited as long as it is used as an oxidizing agent, and examples thereof include potassium permanganate, sodium permanganate, silver permanganate, magnesium permanganate, calcium permanganate, barium permanganate, and ammonium permanganate. One type of permanganate may be used alone, or two or more types may be used in combination.

[0087] The carrier layer can be prepared by uniformly adding an aqueous solution of permanganate to the surface of a granular carrier, and then removing water by heating under reduced pressure so that a certain degree of water content is maintained.

[0088] When a carrier layer with a permanganate fixed thereto is used, the carrier layer may be disposed below the silver nitrate silica gel layer 210. In this case, a part of the SOx gas generated in the sulfuric acid silica gel layer 220 reacts with the silver nitrate of the silver nitrate silica gel layer 210 to generate NOx gas, but the SOx gas generated in the sulfuric acid silica gel layer 210 and the NOx gas generated in the silver nitrate silica gel layer 210 are consumed in the carrier layer with a permanganate fixed thereto.

[0089] The drawings referred to in the above embodiments show an outline of each part, and do not accurately reflect the structure, shape, size, ratio, etc. of each part. EXAMPLES

[0090] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. The fillers used in the following examples are as follows.

[0091] [Filling material] Silica gel sulfate: The sulfate silica gel was prepared by uniformly adding concentrated sulfuric acid (Fujifilm Wako Pure Chemical Industries, Ltd. product name "Concentrated Sulfuric Acid" 190-04675, for precision analysis) to activated silica gel (Kanto Chemical Co., Ltd.) and then drying. The amount of concentrated sulfuric acid added to the activated silica gel was set so that the amount of sulfuric acid relative to the activated silica gel was 44% by mass.

[0092] Silver nitrate silica gel: An aqueous solution of silver nitrate (product name "Silver Nitrate" 198-00835, special grade reagent, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) dissolved in distilled water was added to activated silica gel (manufactured by Kanto Chemical Co., Ltd.) and mixed uniformly. The mixture was heated to 70°C under reduced pressure using a rotary evaporator and dried to prepare silver nitrate silica gel. Here, the amount of silver nitrate in the silver nitrate silica gel was set to 10% of the mass of the activated silica gel as the silver nitrate aqueous solution, and the amount of silver nitrate in the silver nitrate silica gel was set to 10% of the mass of the activated silica gel.

[0093] Zirconium oxide: Zirconium oxide powder (Alfa Aesar's product name "Zirconium Oxide, catalyst support" was crushed and sieved to a particle size of 250 μm or less) was placed in a tubular furnace and fired for 2.5 hours under a nitrogen flow while controlling the temperature of the tubular furnace to be 1,000°C or less, after which the heating of the tubular furnace was stopped and the tubular furnace was cooled to room temperature. This resulted in the production of activated powdered zirconium oxide.

[0094] [Example 1] An extraction column 1 according to the first embodiment was prepared. Here, 3.3 g of silica gel sulfate was packed to a height of 35 mm in a first column 10 having an inner diameter of 13 mm and a length of 70 mm to form a silica gel sulfate layer 120, and 0.5 g of silica gel (product name "Silica Gel 60 (Spherical)" by Kanto Chemical Co., Ltd.) was packed thereon to a height of 10 mm to form a retaining layer 110. In this way, a treatment layer 100 in which the retaining layer 110 was laminated on the silica gel sulfate layer 120 was formed. In addition, about 0.6 g of zirconium oxide was packed to a height of 35 mm in a second column 20 having an inner diameter of 4.6 mm and a length of 100 mm to form a trapping layer 200. Then, the second column 20 was connected to the lower end of the first column 10 which was raised so that the retaining layer 110 of the treatment layer 100 was on the upper layer side, and an extraction column 1 was prepared.

[0095] Sample A was prepared by mixing 50 μL of a solution obtained by diluting a PCB standard substance solution (Wellington Laboratories' product name "BP-MS") with isooctane to a concentration of 100 ng / mL and 100 μL of hexane.

[0096] The entire amount of sample A was added to the treatment layer 100 of the extraction column 1, and 0.7 mL of n-hexane was further added. Then, 20 mL of n-hexane was supplied from the top end of the first column 10 to the inside at a rate of 2 mL / min, passed through the treatment layer 100 and the capture layer 200 in that order, and flowed out from the bottom end of the second column 20. During this time, the temperature of the treatment layer 100 of the first column 10 was maintained at room temperature (25°C). After the supply of n-hexane was completed, the first column 10 and the second column 20 were separated, and air was supplied to the second column 20, which was turned upside down, in the opposite direction to the direction in which n-hexane passed, to remove n-hexane remaining in the second column 20. At this time, the second column 20 was heated and its temperature was maintained at 85°C.

[0097] Next, 1.2 mL of toluene was supplied to the second column 20, which was kept upside down, in the direction opposite to the flow direction of n-hexane, to extract the PCBs trapped in the trapping layer 200. During this process, the second column 20 was heated to maintain the temperature of the trapping layer 200 at 85°C, and about 1 mL of toluene solution discharged from the second column 20 was collected as an extract of PCBs. It took about 0.7 hours from the addition of sample A and n-hexane until this extract was obtained.

[0098] The recovery rate of each congener of PCBs was calculated for the obtained extract. Here, 100μL of a solution of PCBs internal standard substance solution (Wellington Laboratories' product name "MBP-MXP") for calculating the recovery rate, diluted with isooctane to a concentration of 20ng / mL, was added to the extract concentrated to 350μL to prepare an analytical sample, and the recovery rate of each congener of PCBs was calculated by analyzing this analytical sample by HRGC / LRMS method with reference to the method described in the "Provisional Manual for the Investigation of Exogenous Endocrine Disrupting Chemicals" presented by the Environment Agency in October 1998. The results are shown in Figure 5. In Figure 5, 1Cl to 10Cl on the horizontal axis indicate the number of chlorines in PCBs, and the symbols such as #1 are IUPAC numbers given to each congener of PCBs.

[0099] Figure 5 shows that the recovery rates of PCB congeners with chlorine numbers from 1 to 10 were high, indicating that few PCB congeners were missed during the extraction process.

[0100] [Example 2] An extraction column 2 according to the second embodiment was prepared. Here, 8.5 g of sulfate silica gel was packed to a height of 80 mm in a first column 10 having an inner diameter of 12.5 mm and a length of 200 mm, to form a sulfate silica gel layer 220, and 4.4 g of silver nitrate silica gel was packed thereon to a height of 60 mm, to form a silver nitrate silica gel layer 210. In this way, a treatment layer 100 was formed in which the silver nitrate silica gel layer 210 was laminated on the sulfate silica gel layer 220. In addition, a capture layer 200 was formed by packing 0.75 g of zirconium oxide to a height of 28 mm in a second column 20 having an inner diameter of 6 mm and a length of 50 mm. Then, a second column 20 was connected to the lower end of the first column 10, which was raised so that the silver nitrate silica gel layer 210 of the treatment layer 100 was on the upper layer side, to prepare an extraction column 2.

[0101] 10 μL of a solution of PCBs standard substance (Wellington Laboratories' product name "BP-MS") diluted with decane to a concentration of 20 ng / mL was mixed with an n-hexane solution containing 0.2% toluene to prepare 1 mL of sample B.

[0102] After the treatment layer 100 of the extraction column 2 was moistened by adding 1 mL of n-hexane, the entire amount of sample B was added to the treatment layer 100. Next, 1 mL of n-hexane was added to the treatment layer 100 three more times, and then the entire silver nitrate silica gel layer 210 of the treatment layer 100 and the upper half of the sulfate silica gel layer 220 were heated to 60°C. Then, 85 mL of n-hexane was gradually supplied to the treatment layer 100, and this n-hexane was passed through the treatment layer 100 and the trapping layer 200 in this order. After the n-hexane passed through the trapping layer 200, compressed air was passed through the opening at the bottom end of the second column 20 to the branch path 22, and the trapping layer 200 was dried. After the trapping layer 200 was heated to 90° C., the upper opening of the first column 10 was airtightly closed, and 2.5 mL of toluene was supplied to the trapping layer 200 from the lower opening of the second column 20. The total amount of toluene that passed through the trapping layer 200 was collected as an extract via the branch path 22. It took about 1.5 hours from the addition of sample B until the extract was obtained.

[0103] The recovery rate of each congener of PCBs was calculated for the obtained extract. Here, 20 μL of a solution of PCB internal standard for recovery rate calculation (Wellington Laboratories' product name "PCB-LCS-H") diluted with decane to a concentration of 10 ng / mL was added to the extract concentrated to 20 μL, and the volume was adjusted to 50 μL by adding more decane to prepare an analytical sample. This analytical sample was quantitatively analyzed by HRGC-HRMS method, and the recovery rate of each congener of PCBs was calculated. The results are shown in Figure 6. In Figure 6, the indications of 1Cl to 10Cl on the horizontal axis and the indications such as #1 are the same as those in Figure 5.

[0104] Figure 6 shows that the recovery rates of PCB congeners with chlorine numbers from 1 to 10 were generally high, indicating that few PCB congeners were missed during the extraction process.

[0105] [Example 3] A PBDEs standard substance solution ("MASS-LABELLED PBDE CONGENERS" product name of Wellington Laboratories) was diluted 50-fold with isooctane, and 50 μL of the solution was mixed with 100 μL of hexane to prepare sample C. Then, the entire amount of sample C was used to carry out the extraction operation in the same manner as in Example 1.

[0106] The recovery rate of each PBDE congener was calculated for the resulting extract. Here, the extract was concentrated to about 50 μL, and 50 μL of a solution of PBDE internal standard substance solution (Wellington Laboratories' product name "BFR-ISS") for calculating the recovery rate, diluted 50 times with isooctane, was added. This solution was further concentrated to 50 μL to prepare an analytical sample, which was then analyzed by HRGC / HRMS to calculate the recovery rate of each PBDE congener. The results are shown in Table 1.

[0107] [Table 1]

[0108] As shown in Table 1, the recovery rates of each PBDE congener were generally high, with a few exceptions, indicating that little PBDE was lost during the extraction process.

[0109] [Example 4] A second column 20 according to embodiment 4 shown in Fig. 4 was produced. Here, 1 g of zirconium oxide was wet-packed using n-hexane into a glass column having an inner diameter of 14.6 mm and a length of 20 cm, and the resulting trapping layer 200 was fixed by a frit to produce the second column 20.

[0110] Sample D was prepared by mixing 50 μL of a decane solution containing oxychlordane, cis-chlordane, trans-chlordane, cis-nonachlor, and trans-nonachlor as chlordanes at concentrations of 0.1 mg / L each with 100 μL of n-hexane. The entire amount of sample D was added to the upright second column 20 from the upper opening, followed by the addition of 2 mL of n-hexane, and then gradually adding 20 mL of n-hexane and passing the column through. After the n-hexane had passed through, 40 mL of a 25% diethyl ether-containing n-hexane solution was supplied from the lower opening of the second column 20 and passed through, and an extract was obtained from the upper opening of the second column 20.

[0111] The recovery rate of each chlordane was calculated for the obtained extract. 13 A C internal standard solution (trade name "EXPANDED POPS PESTICIDES CLEANUP SPIKE" by Cambridge Isotope Laboratories, Inc.) was added and concentrated to 20 μL to prepare an analytical sample. The analytical sample was analyzed by HRGC / HRMS to calculate the recovery rate of each chlordanes. The results are shown in Table 2.

[0112] [Table 2]

[0113] Table 2 shows that the recovery rates of each chlordane were high, and little was lost due to the type of chlordane during the extraction process. [Explanation of symbols]

[0114] 1, 2, 3 Extraction columns 10 Column 1 20 Column 2 100 Processing Layer 200 acquisition layer

Claims

1. 1. A method for extracting an organohalogen compound from a solution containing said compound, comprising: adding the solution to a trapping layer capable of trapping the organic halogen compound; supplying an aliphatic hydrocarbon solvent through the capture bed to which the solution has been added; supplying and passing an extraction solvent for the organic halogen compound through the capture layer through which the aliphatic hydrocarbon solvent has passed; retaining the extraction solvent that has passed through the capture bed; Including, The trapping layer contains granular zirconium oxide (excluding those containing metal oxide-modified aluminum oxide), Method for extracting organohalogen compounds.

2. 1. A method for extracting an organohalogen compound from a solution containing said compound and contaminants, comprising: adding the solution to a treatment layer capable of treating the impurities; supplying an aliphatic hydrocarbon solvent to the treatment bed to which the solution has been added and passing the solvent through the treatment bed; supplying the aliphatic hydrocarbon solvent that has passed through the treatment layer to a trapping layer capable of trapping the organic halogen compounds, and allowing the aliphatic hydrocarbon solvent to pass through the treatment layer; supplying and passing an extraction solvent for the organic halogen compound through the capture layer through which the aliphatic hydrocarbon solvent has passed; retaining the extraction solvent that has passed through the capture bed; Including, The trapping layer contains granular zirconium oxide (excluding those containing metal oxide-modified aluminum oxide), Method for extracting organohalogen compounds.

3. 3. The method for extracting organic halogen compounds according to claim 2, wherein the solution is obtained by extracting organic halogen compounds using a solvent from a material layer at the bottom of the hydrosphere or on the surface of land, food, a biological sample, environmental water, wastewater, electrical insulating oil, incineration ash, or a collector that has collected gaseous contents.

4. A column for extracting an organic halogen compound from a solution containing the organic halogen compound and impurities, comprising: a first column packed with a treatment layer capable of treating the impurities; a second column packed with a trapping layer capable of trapping organic halogen compounds, the second column being detachably connected to the first column; Equipped with The trapping layer contains granular zirconium oxide (excluding those containing metal oxide-modified aluminum oxide), A column for the extraction of organic halogen compounds.

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