JP2006275821A - Method and apparatus for prepararing sample for analysis of dioxins - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily prepare a hydrophilic sample of high reliability for the analysis of dioxins suitable for analysis by a bioassay method from a hydrophobic solvent solution of dioxins in a short period of time. <P>SOLUTION: A hexane solution of dioxins is supplied to a rear stage column 22 filled with a silica gel based filler 22a, and dichlorometane-containing hexane is supplied to the rear stage column 22, to which the hexane solution is supplied, from a first solvent supply part 60. The dichlorometane-containing hexane supplied to the rear stage column 22 is passed through the rear stage column 22 while dissolving dioxins in the hexane solution and subsequently passed through a solvent substituting column 30 filled with an alumina filler 30a. The dioxins dissolved in the dichlorometane-containing hexane are captured by the alumina filler 30a. Dimethyl sulfoxide is supplied to the solvent substituting column 30 from a second solvent supply part 70 in a direction reverse to the passing direction of the dichlorometane-containing hexane to be passed through the column 30 and ensured to obtain a target sample for the analysis of dioxins. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an analytical sample preparation method and preparation apparatus, and more particularly to a dioxin analysis sample preparation method and preparation apparatus.

  Since dioxins are highly toxic environmental pollutants, the Act on Special Measures for Countermeasures against Dioxins (1999 Act No. 105) stipulates water such as exhaust gas from the waste incineration facility, air, industrial wastewater and river water. It is obliged to regularly analyze the fly ash generated in waste incineration facilities and dioxins contained in soil. Here, the term “dioxins” in the present application follows the provisions of Article 2 of the Special Measures Law for Countermeasures against Dioxins, and in addition to polychlorinated dibenzo-para-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), coplanar polychlorinated Used to mean biphenyl (Co-PCBs).

  When analyzing dioxins contained in a fluid such as exhaust gas or water or in soil, it is necessary to first collect dioxins contained in a sample such as exhaust gas or soil as an analysis sample. For example, as a method for collecting a sample for analysis of dioxins contained in exhaust gas, a method using a glass impinger described in Non-Patent Document 1 or a filter described in Patent Documents 1, 2, and 3 is used. The method is known. In these methods, generally, a sample for analysis of dioxins is finally obtained as an extract of several tens to several tens of milliliters using a hydrophobic solvent such as toluene or n-hexane. The obtained extract is purified using a multilayer silica gel column or the like and then usually analyzed using a gas chromatograph mass spectrometer (GC / MS).

  By the way, dioxins are a general term for many types of compounds, and there are strong and weak toxic substances. Therefore, in the analysis of dioxins, it is often practical and useful to quantify as a toxic equivalent (TEQ value) and evaluate based on it, rather than performing an overall quantitative evaluation. Therefore, bioassay methods such as an immunoassay method (for example, ELISA method), EROD method, and DR-CALUX method have been proposed as methods for simply and rapidly evaluating the TEQ value of dioxins (for example, Patent Document 4). And non-patent documents 2 to 9).

  The bioassay method is an analytical technique applying a biological reaction such as an antigen-antibody reaction, and in order to implement it, a sample for analysis in which collected dioxins are dissolved in a small amount of a hydrophilic solvent solution is required. In order to prepare this analytical sample, the above-described extract using a hydrophobic solvent, that is, a hydrophobic solvent solution of dioxins is usually purified using a multilayer silica gel column or the like, and then the dioxins are dissolved. The hydrophilic solvent suitable for bioassay methods such as dimethyl sulfoxide (DMSO) and alcohol is replaced with a hydrophilic solvent solution of dioxins obtained in this way, about several milliliters or less than 1 milliliter. Need to be concentrated to a small amount.

  By the way, the method for substituting and concentrating a hydrophobic solvent with a hydrophilic solvent in the above-mentioned extract is described in Non-Patent Document 8 and Non-Patent Document 9, for example. In the methods described in these documents, basically, the hydrophobic solvent is removed from the purified extract using an evaporator under reduced pressure, and a hydrophilic solvent such as DMSO is added to the residue (ie, dioxin sample). Is added to dissolve the residue. Further, if necessary, nitrogen gas is blown onto the obtained hydrophilic solvent solution to further concentrate the hydrophilic solvent solution. Thus, a target sample, that is, a hydrophilic dioxin analysis sample suitable for a bioassay method can be obtained.

  However, in the methods described in Non-Patent Documents 8 and 9, the operation for removing the hydrophobic solvent from the hydrophobic solvent solution of dioxins and the dioxin sample after removing the hydrophobic solvent are dissolved in the hydrophilic solvent. Therefore, the operation is complicated, and it takes a long time to obtain a sample for analysis of dioxins. In addition, this analytical sample often lacks reliability because, for example, the concentration of dioxins may fluctuate due to the skill of the operator, and the accuracy of the analytical value is not constant. Furthermore, the above-mentioned extract, that is, the hydrophobic solvent solution of dioxins, does not contain polychlorinated polycyclic aromatic hydrocarbons other than dioxins such as polychlorinated naphthalene, even after purification with a multilayer silica gel column or the like. May include as. Polychlorinated polycyclic aromatic hydrocarbons other than dioxins remain after replacing the hydrophobic solvent of the extract with a hydrophilic solvent, and have cross-reactivity with antibodies and Ah receptors as with dioxins. In the bioassay method, the TEQ value of dioxins may be overestimated, and the reliability of the analysis result may be impaired.

  An object of the present invention is to prepare a highly reliable hydrophilic dioxin analysis sample easily and in a short time from a hydrophobic solvent solution of dioxins.

Japanese Industrial Standard JIS K 0311: 1999 established on September 20, 1999 Wako Pure Chemical Industries, Ltd. “Dioxin ELISA Kit Wako” product information, [Search March 8, 2005], Internet <URL: http://www.wako-chem.co.jp/siyaku/journal/anal /pdf/anal27.pdf> Cosmo Bio Co., Ltd. “Immuno Eco DXN” technical data, [March 17, 2005 search], Internet <URL: http://search.cosmobio.co.jp/cosmo_search_p/search_gate2/docs/CRI_EDXN.20030206. pdf> “Insert for DF1 Dioxin / Furan Immunoassay Kit” by CAPE Technologies LLC, USA (searched March 8, 2005), Internet <URL: http: // www.cape-tech.com/IN-DF1.pdf> Product information of Toyobo Co., Ltd. “Dioxin ELISA Kit”, [Search March 8, 2005], Internet <URL: http://www.toyobo.co.jp/seihin/xr/olul/upld71/new/ dioxinelis71nr06.pdf> Product information of Kubota “Ah Immunoassay”, [March 8, 2005 search], Internet <URL: http://tdh.kubota.co.jp/ahi/main1.html> Wako Pure Chemical Industries, Ltd. “DIOXIN RIsc TEST” product information, [March 17, 2005 search], Internet <URL: http://www.wako-chem.co.jp/siyaku/info/env/ pdf / dioxin.pdf> “Bioassay monitoring in the dechlorination treatment of dioxins”, Abstracts of the 11th Environmental Chemistry Conference, Japan Environmental Chemistry Society, June 3-5, 2002, pages 430-431 Organohalogen Compounds, 45, 200-203 (2000)

Japanese Patent No. 327396 WO01 / 91883 JP 2004-53388 A JP 2001-226371 A

  The sample preparation method for dioxins analysis according to the present invention is a method for preparing a sample for analysis of hydrophilic dioxins from a hydrophobic solvent solution of dioxins, to the first column packed with silica gel-based packing material. A step of supplying a hydrophobic solvent solution of dioxins, a step of supplying and passing a dichloromethane-containing aliphatic hydrocarbon solvent through the first column supplied with the hydrophobic solvent solution of dioxins, and an alumina-based filler Supplying the dichloromethane-containing aliphatic hydrocarbon solvent after passing through the first column to the second column packed with the bismuth, and passing the dichloromethane-containing aliphatic hydrocarbon solvent to the second column after passing through the dichloromethane-containing aliphatic hydrocarbon solvent. Supplying and passing a hydrophilic solvent capable of dissolving dioxins in a direction opposite to the passing direction of the group hydrocarbon solvent; And a step of securing the hydrophilic solvent passed through the column.

  In this preparation method, the dioxins in the hydrophobic solvent solution supplied to the first column are dissolved in the dichloromethane-containing aliphatic hydrocarbon solvent supplied to the first column, and together with the dichloromethane-containing aliphatic hydrocarbon solvent. Pass through the first column. At this time, impurities contained in the dichloromethane-containing aliphatic hydrocarbon solvent are trapped by the silica gel packing material except for polychlorinated polycyclic aromatic hydrocarbons other than dioxins such as polychlorinated naphthalene, and are contained in the first column. stay. When the dichloromethane-containing aliphatic hydrocarbon solvent that has passed through the first column is supplied to the second column, the dioxins dissolved in the dichloromethane-containing aliphatic hydrocarbon solvent are removed when the dichloromethane-containing aliphatic hydrocarbon solvent passes through the second column. Is trapped by the alumina filler and remains in the second column. Then, when dioxins captured by the alumina filler are passed through the second column by supplying a hydrophilic solvent in a direction opposite to the passing direction of the dichloromethane-containing aliphatic hydrocarbon solvent, the hydrophilic solvent is passed through the dioxins. Dissolved in and extracted. Therefore, if the hydrophilic solvent supplied to the second column is secured after passing through the second column, a sample for hydrophilic analysis of dioxins can be obtained.

  Here, dioxins dissolved in the dichloromethane-containing aliphatic hydrocarbon solvent supplied from the first column to the second column are mainly inflow side of the dichloromethane-containing aliphatic hydrocarbon solvent in the second column. Stays near the edge. Therefore, the dioxins are dissolved in a small amount of a hydrophilic solvent that passes in the direction opposite to the passing direction of the dichloromethane-containing aliphatic hydrocarbon solvent with respect to the second column, and are easily extracted from the second column. Therefore, the hydrophilic dioxins analysis sample obtained by this preparation method does not contain an excessive hydrophilic solvent and is set to a small amount.

  Incidentally, polychlorinated polycyclic aromatic hydrocarbons other than dioxins contained in the dichloromethane-containing aliphatic hydrocarbon solvent supplied from the first column to the second column are not trapped by the alumina filler, and dichloromethane Pass through the second column with the containing aliphatic hydrocarbon solvent. For this reason, the sample for hydrophilicity analysis of dioxins obtained by the above-described method is substantially free of polychlorinated polycyclic aromatic hydrocarbons other than dioxins that may inhibit the analysis of dioxins, High reliability.

  This preparation method usually further includes a step of supplying an inert gas to the second column before supplying the hydrophilic solvent to the second column. In this case, since the dichloromethane-containing aliphatic hydrocarbon solvent remaining in the second column before supplying the hydrophilic solvent can be removed by an inert gas stream, the dichloromethane-containing aliphatic hydrocarbon solvent is hardly contained as an impurity. A hydrophilic analytical sample can be obtained.

  In this preparation method, for example, a hydrophilic solvent can be supplied to the second column while heating the second column. In this way, dioxins captured in the second column can be extracted with a smaller amount of a hydrophilic solvent.

  An apparatus for preparing a sample for analyzing dioxins according to the present invention is for preparing a sample for analyzing hydrophilic dioxins from a hydrophobic solvent solution of dioxins, and comprises a first column packed with a silica gel-based filler, , A second column packed with an alumina-based filler, a supply path for supplying a hydrophobic solvent solution of dioxins to the first column, and a second column for supplying a dichloromethane-containing aliphatic hydrocarbon solvent to the first column. A solvent supply section, a column communication path for supplying the dichloromethane-containing aliphatic hydrocarbon solvent from the first column to the second column, and a hydrophilic solvent capable of dissolving dioxins in the second column. A second solvent supply unit for supplying and a discharge path for discharging the hydrophilic solvent that has passed through the second column are provided. Here, the second solvent supply unit is set to be able to supply the hydrophilic solvent to the second column in a direction opposite to the supply direction of the dichloromethane-containing aliphatic hydrocarbon solvent from the column communication path to the second column. Yes.

  In this preparation apparatus, dioxins in the hydrophobic solvent solution supplied from the supply path to the first column are dissolved in the dichloromethane-containing aliphatic hydrocarbon solvent supplied from the first solvent supply unit to the first column, and dichloromethane is added. Pass through the first column with the containing aliphatic hydrocarbon solvent. At this time, impurities contained in the hydrophobic solvent solution are captured by the silica gel-based packing material except for polychlorinated polycyclic aromatic hydrocarbons other than dioxins such as polychlorinated naphthalene, and remain in the first column. After passing through the first column, the dioxins dissolved in the dichloromethane-containing aliphatic hydrocarbon solvent supplied to the second column through the column communication path are not removed when the dichloromethane-containing aliphatic hydrocarbon solvent passes through the second column. It is captured by the alumina-based filler and remains in the second column. Then, when the hydrophilic solvent is supplied from the second solvent supply unit to the second column in the direction opposite to the passing direction of the dichloromethane-containing aliphatic hydrocarbon solvent, the dioxins trapped in the alumina-based filler are It is extracted by dissolving in an organic solvent and discharged from the discharge channel as a sample for analyzing hydrophilic dioxins.

  Here, dioxins dissolved in the dichloromethane-containing aliphatic hydrocarbon solvent supplied from the first column to the second column are mainly inflow side of the dichloromethane-containing aliphatic hydrocarbon solvent in the second column. Stays near the edge. Therefore, the dioxins are dissolved in a small amount of a hydrophilic solvent that passes in the direction opposite to the passing direction of the dichloromethane-containing aliphatic hydrocarbon solvent with respect to the second column, and are easily extracted from the second column. Therefore, the hydrophilic dioxin analysis sample obtained by this preparation apparatus does not contain an excessive hydrophilic solvent and is set to a small amount.

  Incidentally, polychlorinated polycyclic aromatic hydrocarbons other than dioxins contained in the dichloromethane-containing aliphatic hydrocarbon solvent supplied from the first column to the second column are not trapped by the alumina filler, and dichloromethane Pass through the second column with the containing aliphatic hydrocarbon solvent. For this reason, the sample for dioxin hydrophilicity analysis obtained by this preparation apparatus is substantially free of polychlorinated polycyclic aromatic hydrocarbons other than dioxins that may inhibit the analysis of dioxins, High reliability.

  This preparation apparatus usually further includes a gas supply unit for supplying an inert gas to the second column. In this case, since the hydrophobic solvent remaining in the second column before supplying the hydrophilic solvent can be removed by an inert gas stream, a hydrophilic analysis sample that hardly contains the hydrophobic solvent as an impurity is obtained. be able to.

  Moreover, this preparation apparatus may further include, for example, a heating means for the second column. In this case, since the hydrophilic solvent can be supplied to the second column while heating the second column, the dioxins captured in the second column can be extracted with a smaller amount of the hydrophilic solvent.

  Since the sample preparation method for analysis of dioxins according to the present invention includes the steps described above, a highly reliable hydrophilic sample for analysis of dioxins can be easily and quickly prepared from a hydrophobic solvent solution of dioxins. Can be prepared.

  In addition, since the sample preparation device for analyzing dioxins according to the present invention includes the above-described components, a highly reliable hydrophilic sample for analyzing dioxins can be easily obtained from a hydrophobic solvent solution of dioxins. And it can be prepared in a short time.

  With reference to FIG. 1, one form of the preparation apparatus of the sample for dioxin analysis which concerns on this invention is demonstrated. In the figure, the preparation apparatus 1 includes a sample supply path (an example of a supply path) 10, a purification column 20, a solvent replacement column 30 (an example of a second column), a column communication path 40, a solvent discharge path 50, and a first solvent. A supply unit 60, a second solvent supply unit 70, and a gas supply unit 80 are mainly provided.

  The sample supply path 10 is for supplying a hydrophobic solvent solution of dioxins, which will be described later, to the purification column 20 and has a first switching valve 11.

  The purification column 20 is obtained by vertically connecting two columns, a front column 21 and a rear column 22 (an example of a first column). The pre-stage column 21 is open in the vertical direction, and the sample supply path 10 communicates with the opening on the upper side, so that the granular form for temporarily holding the hydrophobic solvent solution from the sample supply path 10 The holding material 21a is filled. The holding material 21a can hold the hydrophobic solvent solution in the gaps between the particles, and can elute dioxins in the hydrophobic solvent solution when a dichloromethane-containing aliphatic hydrocarbon solvent described later is supplied. Various materials can be used as long as they are used. For example, silica gel, alumina, diatomaceous earth, and sodium sulfate are preferably used. Two or more types of these holding materials 21a may be mixed and used as necessary.

  On the other hand, the latter column 22 is for removing impurities other than dioxins (excluding polychlorinated polycyclic aromatic hydrocarbons) from the hydrophobic solvent solution, and is open in the vertical direction, and The silica gel filler 22a is filled. The silica gel filler 22a is not particularly limited as long as it can capture the above-mentioned impurities contained in the hydrophobic solvent solution. Usually, silica gel, silver nitrate silica gel, or sulfuric acid silica gel is used. Is preferred. Two or more types of these silica gel fillers 22a may be used in combination. In this case, the silica gel-based packing material 22a may be packed in a state where two or more types are mixed in the rear column 22, or two or more types may be packed in multiple layers.

  The solvent replacement column 30 is packed with an alumina filler 30a for capturing dioxins dissolved in a dichloromethane-containing aliphatic hydrocarbon solvent, which will be described later, and is open in the vertical direction, and A first heating device 31 such as a heater is provided. The type of the alumina filler 30a is not limited, but usually any of basic alumina, neutral alumina, and acidic alumina can be used.

  The column communication path 40 is for connecting the rear column 22 of the purification column 20 and the solvent replacement column 30, one end of which communicates with the opening on the lower side of the rear column 22, and the other The end communicates with the opening on the upper side of the solvent replacement column 30. The column communication path 40 has a second switching valve 41. One end of an analysis sample discharge path 42 (an example of a discharge path) communicates with the second switching valve 41, and the end of the analysis sample discharge path 42 is open.

  The solvent discharge path 50 extends from an opening on the lower side of the solvent replacement column 30, has a third switching valve 51, and is open at the end. A solvent recovery tank (not shown) is disposed at the end of the solvent discharge path 50.

  The first solvent supply unit 60 includes a first solvent tank 61 and a first solvent supply path 62 extending from the first solvent tank 61. The first solvent tank 61 is for storing a dichloromethane-containing aliphatic hydrocarbon solvent. The first solvent supply path 62 communicates with the first switching valve 11, and a first pump 63 for sending the dichloromethane-containing aliphatic hydrocarbon solvent in the first solvent tank 61 toward the first switching valve 11. have.

  The dichloromethane-containing aliphatic hydrocarbon solvent stored in the first solvent tank 61 is a mixed solvent of an aliphatic hydrocarbon solvent and dichloromethane. Although the aliphatic hydrocarbon solvent used here is not specifically limited, Usually, a C5-C10 nonpolar thing, for example, n-hexane, isooctane, nonane, and decane are preferable. In particular, it is preferable to use n-hexane. The aliphatic hydrocarbon solvent may be the same as or different from the hydrophobic solvent used in the hydrophobic solvent solution of dioxins described later. The dichloromethane concentration in the dichloromethane-containing aliphatic hydrocarbon solvent is usually preferably 0.5 to 10% by volume, more preferably 1 to 5% by volume. When the dichloromethane concentration is less than 0.5% by volume, there is a possibility that the analytical sample described later contains polychlorinated polycyclic aromatic hydrocarbons other than dioxins. Conversely, when the concentration exceeds 10% by volume, a part of dioxins contained in the primary treatment liquid described later may pass through the solvent replacement column 30. In addition, the dioxins may expand to the lower side of the solvent replacement column 30, and a large amount of hydrophilic solvent may be required to extract the dioxins captured in the solvent replacement column 30. .

  The second solvent supply unit 70 includes a second solvent tank 71 and a second solvent supply path 72 extending from the second solvent tank 71. The second solvent tank 71 is for storing a hydrophilic solvent, and has a second heating device (not shown) for heating and heating the hydrophilic solvent. The hydrophilic solvent used here is not particularly limited as long as it can dissolve dioxins in a small amount, but is usually dimethyl sulfoxide (DMSO) or methanol. In particular, dimethyl sulfoxide is preferably used. Further, dimethyl sulfoxide may be added with a surfactant. The surfactant used here is, for example, polyoxyethylene (20) sorbitan monolaurate (for example, trade name “Tween 20” of Unikema) or polyoxyethylene (10) octylphenyl ether (for example, Union Carbide). Product name “Triton X-100”). In general, the amount of the surfactant added is preferably set so that the concentration is 0.001 to 1% by weight, and more preferably 0.01 to 0.2% by weight.

  The second solvent supply path 72 communicates with the third switching valve 51, and has a second pump 73 for sending the hydrophilic solvent in the second solvent tank 71 toward the third switching valve 51. Yes.

  The gas supply unit 80 includes a gas cylinder 81 of an inert gas such as nitrogen, and a gas supply pipe 82 extending from the gas cylinder 81 and connected to the second switching valve 41.

  In the preparation apparatus 1 described above, the first switching valve 11 has a flow path for either communication between the sample supply path 10 and the front column 21 or communication between the first solvent supply path 62 and the front column 21. It is for switching. Further, the second switching valve 41 communicates between the rear column 22 and the solvent replacement column 30, communicates between the gas supply pipe 82 and the solvent replacement column 30, or discharges the solvent replacement column 30 and the analysis sample. This is for switching the flow path to one of the connections with the path 42. Further, the third switching valve 51 switches the flow path to either communication between the solvent replacement column 30 and the solvent discharge path 50 or communication between the second solvent supply path 72 and the solvent replacement column 30. Is for.

  Next, the preparation method of the sample for dioxin analysis using the above-mentioned preparation apparatus 1 is demonstrated. First, the first switching valve 11, the second switching valve 41, and the third switching valve 51 are set to a predetermined initial state. That is, the first switching valve 11 is set so that the sample supply path 10 and the front column 21 communicate with each other. The second switching valve 41 is set so that the rear column 22 and the solvent replacement column 30 communicate with each other. The third switching valve 51 is set so that the solvent replacement column 30 and the solvent discharge path 50 communicate with each other.

  Next, a hydrophobic solvent solution of dioxins is supplied to the sample supply path 10. The hydrophobic solvent solution of dioxins supplied here is, for example, an apparatus described in Japanese Industrial Standard JIS K 0311: 1999 (Non-Patent Document 1 mentioned above) established on September 20, 1999 or Japanese Patent No. 327396 ( Exhaust gas generated from an incineration facility using a filter or the like described in Patent Document 1), WO01 / 91883 (Patent Document 2) or JP 2004-53388 (Patent Document 3) Extraction obtained by collecting dioxins contained in fluids such as factory wastewater and extracting dioxins collected in organic solvents or dioxins contained in soil or fly ash with organic solvents Liquid. These extracts are usually obtained by extracting dioxins in a specimen such as fluid, soil, or fly ash using a hydrophobic solvent such as an aliphatic hydrocarbon solvent such as n-hexane by the operation as described above. If it is obtained, it can be used as it is as the above-mentioned hydrophobic solvent solution. On the other hand, when these extracts are obtained by extraction using another organic solvent, such as toluene, the extract uses the organic solvent used for extraction as a hydrophobic solvent such as n-hexane. If it substitutes, it can utilize as the above-mentioned hydrophobic solvent solution. Here, the hydrophobic solvent used for extraction or solvent replacement is usually preferably an aliphatic hydrocarbon solvent having 5 to 10 carbon atoms, and examples thereof include n-hexane, isooctane, nonane and decane. Of these, n-hexane is an inexpensive solvent and can be particularly preferably used.

  The hydrophobic solvent solution of dioxins supplied to the sample supply path 10 is supplied to the upstream column 21 of the purification column 20 through the sample supply path 10 and is held by the holding material 21a. When the entire amount of the hydrophobic solvent solution is supplied to the front column 21, the first switching valve 11 is operated to set the first solvent supply path 62 and the front column 21 to communicate with each other. Operate. Thereby, the dichloromethane-containing aliphatic hydrocarbon solvent in the first solvent tank 61 is continuously supplied to the pre-stage column 21 through a part of the first solvent supply path 62 and the sample supply path 10.

  The initial dichloromethane-containing aliphatic hydrocarbon solvent supplied to the former column 21 moves the hydrophobic solvent solution of dioxins held in the holding material 21 a of the former column 21 to the latter column 22. As a result, the hydrophobic solvent solution of dioxins is supplied to the subsequent column 22. At this time, when silica gel or alumina is used as the holding material 21a of the former column 21, a part of impurities other than dioxins contained in the hydrophobic solvent solution is polychlorinated polycyclic aromatic hydrocarbons such as polychlorinated naphthalene. Except for the kind, it is captured by the holding material 21a. That is, the hydrophobic solvent solution is subjected to preliminary purification treatment in the former column 21.

  The dichloromethane-containing aliphatic hydrocarbon solvent subsequently supplied from the first solvent tank 61 to the front column 21 passes through the front column 21 and is supplied to the rear column 22. The dichloromethane-containing aliphatic hydrocarbon solvent supplied to the latter column 22 passes through the latter column 22 while dissolving the dioxins in the hydrophobic solvent solution supplied to the latter column 22. At this time, impurities other than dioxins contained in the hydrophobic solvent solution are trapped by the silica gel filler 22a except for polychlorinated polycyclic aromatic hydrocarbons other than dioxins. That is, the hydrophobic solvent solution is purified in the subsequent column 22.

  In the above process, the first pump 63 is configured so that the amount of the dichloromethane-containing aliphatic hydrocarbon solvent supplied from the first solvent tank 61 is sufficient for the total amount of dioxins contained in the hydrophobic solvent solution supplied to the downstream column 22. To an amount that can be dissolved in Thus, the dichloromethane-containing aliphatic hydrocarbon solvent supplied from the first solvent tank 61 is used as a purified solution in which substantially all of the dioxins contained in the hydrophobic solvent solution supplied to the subsequent column 22 are dissolved. 22 to the column communication path 40.

  The above-described purified solution (hereinafter referred to as “primary treatment liquid”, the solvent contained in the primary treatment liquid is referred to as “primary solvent”) from the latter column 22 passes through the column communication path 40 and is a column for solvent replacement. 30 is continuously supplied to the upper end side. Dioxins contained in the primary treatment liquid supplied to the solvent replacement column 30 are captured by the alumina-based filler 30a when the primary treatment liquid passes through the solvent replacement column 30 from the upper end side toward the lower end side. . Further, polychlorinated polycyclic aromatic hydrocarbons other than dioxins such as polychlorinated naphthalene contained as impurities in the primary treatment liquid are not captured by the alumina-based filler 30a and pass through the solvent replacement column 30 together with the primary solvent. To do. Therefore, only the primary solvent substantially containing polychlorinated polycyclic aromatic hydrocarbons other than dioxins is discharged from the solvent replacement column 30, and this primary solvent passes through the solvent discharge path 50 to be a solvent recovery tank (see FIG. (Not shown).

  Here, the dioxins contained in the primary treatment liquid are easily captured by the alumina filler 30a packed in the solvent replacement column 30. For this reason, as shown in FIG. 1, the dioxins are mainly trapped in the vicinity of the upper end X of the solvent replacement column 30 in a concentrated manner.

  Next, the second switching valve 41 is operated so that the gas supply pipe 82 and the solvent replacement column 30 communicate with each other, and the inert gas is supplied from the gas cylinder 81 to the gas supply pipe 82. The inert gas supplied to the gas supply pipe 82 passes through a part of the column communication path 40 from the second switching valve 41 and is supplied to the solvent replacement column 30. The inert gas supplied to the solvent replacement column 30 passes through the solvent replacement column 30 and is discharged from the solvent discharge path 50 to the outside. At this time, the primary solvent remaining in the solvent replacement column 30 is diffused into the inert gas passing through the solvent replacement column 30 and discharged to the outside together with the inert gas. As a result, the alumina-based packing material 30a packed in the solvent replacement column 30 is dried so as not to substantially contain the primary solvent.

  In the above-described drying process of the alumina filler 30a, the inert gas is supplied to the solvent replacement column 30 for a predetermined time, and then the first heating device 31 is operated to heat the solvent replacement column 30. Is preferred. If it does in this way, the time which the drying process of the alumina type filler 30a requires can be shortened effectively. In this drying process, if the first heating device 31 is operated from the beginning to heat the solvent replacement column 30, some of the dioxins held in the alumina filler 30 a are eluted from the solvent replacement column 30. Therefore, there is a possibility that a highly reliable hydrophilic dioxin analysis sample cannot be obtained.

  Next, the first heating device 31 is operated or the operation of the first heating device 31 is maintained, and the solvent replacement column 30 is heated. Further, the second switching valve 41 is operated to set so that the solvent replacement column 30 and the analysis sample discharge passage 42 communicate with each other. Further, the third switching valve 51 is operated so that the second solvent supply path 72 and the solvent replacement column 30 communicate with each other. When the second pump 73 is operated in this state, the hydrophilic solvent stored in the second solvent tank 71 passes through a part of the second solvent supply path 72, the third switching valve 51, and the solvent discharge path 50. The solvent replacement column 30 is continuously supplied from the lower end side toward the upper end side. In other words, the hydrophilic solvent is supplied in a direction opposite to the direction of passage of the primary treatment liquid in the solvent replacement column 30.

  The hydrophilic solvent supplied to the solvent replacement column 30 extracts dioxins captured by the alumina filler 30a and flows to the analysis sample discharge passage 42. Therefore, if a hydrophilic solvent (that is, a hydrophilic solvent solution of dioxins) discharged from the analysis sample discharge passage 42 is secured, a target hydrophilic dioxin analysis sample can be obtained. Since the primary solvent is removed from the alumina-based packing material 30a of the solvent replacement column 30 as described above, this analytical sample does not substantially contain the primary solvent and requires a hydrophilic analytical sample. It is suitable for analysis of dioxins by a dioxin analysis method, for example, a bioassay method.

  Here, since the dioxins captured by the alumina filler 30a are intensively captured in the vicinity of the upper end portion X of the solvent replacement column 30 as described above, the travel distance in the solvent replacement column 30 is long. A short, small amount of hydrophilic solvent allows substantially the entire amount to be rapidly extracted. Therefore, a small amount of analysis sample having a higher dioxin concentration than the primary treatment liquid can be obtained from the analysis sample discharge path 42. Specifically, for example, when the amount of the primary treatment liquid supplied from the rear stage column 22 of the purification column 20 to the solvent replacement column 30 is about 100 milliliters, the analysis of the hydrophilic dioxins finally obtained is performed. The sample is greatly concentrated to about 1 milliliter.

  The analytical sample thus obtained is a small amount of concentrated liquid as described above, and polychlorinated polycyclic aromatic hydrocarbons other than dioxins have been removed. It can be used for a class of TEQ analysis samples.

[Other embodiments]

(1) In the above-described embodiment, a hydrophilic solvent is supplied to the heated solvent replacement column 30 to extract dioxins from the alumina filler 30a. However, the solvent replacement column 30 is heated. It does not have to be. However, usually, heating the solvent replacement column 30 reduces the amount of hydrophilic solvent necessary for extracting the dioxins trapped in the alumina filler 30a, and a small amount of highly concentrated analysis. It becomes easier to obtain a sample.

(2) In the above-described embodiment, the purification column 20 is configured in two stages of the front column 21 and the rear column 22, but the present invention can be similarly implemented even when the front column 21 is omitted. However, the impurities contained in the dioxin hydrophobic solvent solution can be more effectively removed, and the reliability of the target hydrophilic dioxin analysis sample can be further improved. 21 is preferably employed.

(3) In the above-described embodiment, a case where each switching valve 11, 41, 51, each pump 63, 73, the first heating device 31, the second heating device (not shown), and the like are manually operated is described. However, these operations can be automated by computer control or the like.

Example 1
Using the preparation apparatus 1 described in the above embodiment, a hydrophilic dioxin analysis sample was prepared. Here, dioxins were roughly extracted from a soil sample contaminated with dioxins using toluene to obtain a crude extract. For this crude extract, cleanup spikes for analysis of dioxins (as shown in Table 1, consisting of 7 types of PCDDs labeled with ¹³ C ₁₂ , 10 types of PCDFs, and 12 types of Co-PCBs). After adding a predetermined amount, the solvent was replaced with 5 ml of n-hexane from toluene.

  The whole amount of the dioxins hydrophobic solvent solution (n-hexane solution) obtained as described above is supplied from the sample supply path 10 to the upstream column 21 of the purification column 20 to prepare a target analytical sample. did. In the preparation apparatus 1, the front column 21 and the rear column 22 and the solvent replacement column 30 of the purification column 20 were set as follows. In the first solvent tank 61, n-hexane containing 2% by volume of dichloromethane (hereinafter referred to as “dichloromethane-containing hexane” in the present example) was stored. In the second solvent tank 71, dimethyl sulfoxide (DMSO) was stored as a hydrophilic solvent.

◎ Front column size: ID 12.5mm, length 20mm
Holding material: silica gel ◎ latter stage column size: inner diameter 12.5mm, length 170mm
Silica gel-based packing material: Multilayer silica gel filled with silver nitrate silica gel, sulfuric acid silica gel and silica gel in multiple layers ◎ Solvent replacement column Size: Inner diameter 6 mm, Length 30 mm
Alumina-based filler: trade name “ICN Alumina B-SuperI” of IC Biomedicals

  In the process of preparing the sample for dioxins analysis, 40 ml of hexane containing dichloromethane was supplied to the purification column 20 at a flow rate of 2.5 ml / min. The dimethyl sulfoxide and the solvent replacement column 30 in the second solvent tank 71 are heated to 60 ° C., and the flow rate of dimethyl sulfoxide supplied from the second solvent tank 71 to the solvent replacement column 30 is set to 1 ml / min. did. Further, nitrogen gas was supplied from the gas supply unit 80 for 3 minutes at a flow rate of 400 ml / min for the drying treatment of the solvent replacement column 30. The dimethyl sulfoxide solution (analytical sample) of dioxins discharged from the analytical sample discharge passage 42 was fractionated and collected by 1 milliliter using a fraction collector. Incidentally, the time required from the start of the supply of dichloromethane-containing hexane to the purification column 20 from the first solvent tank 61 to the first 1 ml fraction of the sample for analysis was 40 minutes.

  For the first 1 milliliter of the analytical sample collected by the fraction collector, dimethyl sulfoxide was replaced with n-hexane to prepare a confirmation sample. The sample for confirmation was analyzed by a high resolution GC / MS method, and the recovery rate of cleanup spikes was determined. The results are shown in Table 1. In addition, when the presence of polychlorinated polycyclic aromatic hydrocarbons other than dioxins in the confirmation sample was examined by the same analysis, the polychlorinated polycyclic aromatic hydrocarbons were not substantially detected. .

  In Table 1, the recovery rate (%) is the ratio of the dioxin amount (B) contained in the confirmation sample to the specific dioxin amount (A) contained in the cleanup spike added to the crude extract. (B / A × 100). According to this result, the cleanup spike had a recovery rate of Co-PCBs of 20% or less, but 90% or more of PCDDs and PCDFs was recovered. Thus, the PCDDs and PCDFs in the added cleanup spike will be substantially contained in the first 1 milliliter fraction of the analytical sample, the first fraction comprising at least the soil It can be used as a sample for analysis for TEQ determination of dioxins based on PCDDs and PCDFs in the sample.

  For samples such as soil with low PCBs contamination, the contribution of Co-PCBs to the TEQ of dioxins is small, so the TEQ of dioxins based on PCDDs and PCDFs in the sample is the first fraction described above. When the bioassay method is carried out using as a sample for analysis, it can be obtained. Therefore, if the above-described preparation apparatus 1 is used, the hydrophilicity suitable for the bioassay method, which is substantially free from polychlorinated polycyclic aromatic hydrocarbons other than dioxins in a short time from an n-hexane solution of dioxins. It is possible to easily prepare a sample for sex dioxins analysis.

Example 2
Samples for analysis (meaning the first 1 ml of the sample for analysis described above in Example 1) were prepared from several types of soil samples by the same method as in Example 1 (hereinafter referred to as “the present method”). For each analytical sample, the TEQ was determined by a bioassay method (hereinafter, the TEQ thus obtained is referred to as “the present method TEQ”).

In addition, from the same several types of soil samples, “Bioassay monitoring in dechlorination treatment of dioxins”, Abstracts of the 11th Environmental Chemistry Conference, Japan Society for Environmental Chemistry, June 3-5, 2002, 430 -431 (the above-mentioned non-patent document 8) and Organohalogen Compounds, 45 , 200-203 (2000) (the above-mentioned non-patent document 9) are analyzed by a manual method (hereinafter referred to as “conventional method”). Samples were prepared, and TEQs were determined by bioassay for each analytical sample (hereinafter, the TEQs obtained thereby were referred to as “conventional TEQs”).

  Furthermore, analytical samples were prepared from the same several types of soil samples by the official method, and TEQs were determined for each analytical sample by the high resolution GC / MS method defined in the official method (hereinafter, the TEQ obtained by this method). Is called "official law TEQ"). The “official method” here means the method described in the “Soil Survey and Measurement Manual for Dioxins” (January 2000, Soil Agriculture Division, Water Quality Conservation Bureau, Environment Agency).

  FIG. 2 shows a result of comparing the present method TEQ and the conventional method TEQ with the official method TEQ. According to FIG. 2, the conventional method TEQ has a low correlation coefficient (r) of 0.42, and the regression equation has a slope of 1.90, which is far from 1. However, this method TEQ has a correlation. The number (r) is as high as 0.73, and the slope of the regression equation is 1.26, which is close to 1. According to this result, the present method TEQ is closer to the official method TEQ than the conventional method TEQ, and the result is more reliable than the conventional method TEQ. Therefore, it can be seen that this method can prepare a highly reliable hydrophilic dioxin analysis sample suitable for bioassay from a hydrophobic solvent solution of dioxins as compared to the conventional method.

1 is a schematic diagram of a sample preparation device for analysis of dioxins according to an embodiment of the present invention. The graph which shows the result of Example 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Preparation apparatus 10 Sample supply path 22 Subsequent column 22a Silica gel type packing material 30 Solvent displacement column 30a Alumina type packing material 31 First heating device 40 Column communication path 42 Analytical sample discharge path 60 First solvent supply part 70 Second solvent Supply section 80 Gas supply section

Claims (6)

A method for preparing a hydrophilic dioxins analysis sample from a hydrophobic solvent solution of dioxins, comprising:
Supplying the hydrophobic solvent solution to a first column filled with a silica gel-based filler;
Supplying and passing a dichloromethane-containing aliphatic hydrocarbon solvent through the first column supplied with the hydrophobic solvent solution;
Supplying and passing the dichloromethane-containing aliphatic hydrocarbon solvent after passing through the first column to a second column packed with an alumina-based filler;
The second column after passing the dichloromethane-containing aliphatic hydrocarbon solvent is supplied with a hydrophilic solvent capable of dissolving the dioxins in a direction opposite to the passing direction of the dichloromethane-containing aliphatic hydrocarbon solvent. A process of
Securing the hydrophilic solvent that has passed through the second column;
Of a sample for analysis of dioxins containing   The method for preparing a sample for analyzing dioxins according to claim 1, further comprising a step of supplying an inert gas to the second column before supplying the hydrophilic solvent to the second column.   The method for preparing a sample for dioxin analysis according to claim 1 or 2, wherein the hydrophilic solvent is supplied to the second column while heating the second column. An apparatus for preparing a sample for analysis of hydrophilic dioxins from a hydrophobic solvent solution of dioxins,
A first column packed with silica gel-based filler;
A second column filled with an alumina filler;
A supply path for supplying the hydrophobic solvent solution to the first column;
A first solvent supply unit for supplying a dichloromethane-containing aliphatic hydrocarbon solvent to the first column;
A column connection for supplying the dichloromethane-containing aliphatic hydrocarbon solvent from the first column to the second column;
A second solvent supply unit for supplying a hydrophilic solvent capable of dissolving the dioxins to the second column;
A discharge path for discharging the hydrophilic solvent that has passed through the second column,
The second solvent supply unit is set to be able to supply the hydrophilic solvent to the second column in a direction opposite to the supply direction of the hydrophobic solvent to the second column from the column communication path. ,
Sample preparation equipment for dioxin analysis.   The dioxin analysis sample preparation apparatus according to claim 4, further comprising a gas supply unit configured to supply an inert gas to the second column. The dioxin analysis sample preparation apparatus according to claim 4 or 5, further comprising heating means for the second column.

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