JP2013148539A - Method for extracting polychloro biphenyl class - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extract a PCB class including a low chloride PCB class, especially a PCB class with the number of chloride being one from oily liquid containing PCB classes in a shorter period of time with a simple operation.SOLUTION: When extracting PCB classes from oily liquid containing the PCB classes, a series of columns 1 comprising a first column 10 including a single layer of a silica gel layer 13 composed of sulfuric silica gel and a second column 20 including an alumina layer 23 detachably connected to the first column 10 by a connection member 30 is used. An aliphatic hydrocarbon solvent is supplied to the silica gel layer 13 after adding the oily liquid to the silica gel layer 13, and the aliphatic hydrocarbon solvent is caused to pass through the silica gel layer 13 and the alumina layer 23 in this order. Until this time, the temperature of the silica gel layer 13 is set to 35°C or less. Next, a hydrophobic solvent that can dissolve the PCB classes is supplied to the alumina layer 23 in a direction opposite from a passing direction of the aliphatic hydrocarbon solvent, and the hydrophobic solvent passing through the alumina layer 23 is secured.

Description

  The present invention relates to a method for extracting polychlorinated biphenyls, and more particularly to a method for extracting polychlorinated biphenyls from an oily liquid containing polychlorinated biphenyls.

  As electrical insulating oils for electrical equipment such as transformers and capacitors, those made of mineral oil containing polychlorinated biphenyls (hereinafter sometimes referred to as “PCBs”) excellent in electrical insulating properties have been widely used. Since the toxicity of PCBs to living organisms has been confirmed, the manufacture and import of PCBs is prohibited in Japan, and the use of electrical insulating oils containing PCBs is substantially prohibited. Yes. However, PCB wastes such as PCB-containing electrical insulation oil used in the past have a concern of causing environmental pollution in the treatment process. Therefore, manufacturers or users of electrical equipment themselves or waste disposal In business operators, etc., it has been kept for a long time until now.

  PCBs are a collective term for a large number of compounds in which there are 10 types from monochlorobiphenyl to decachlorobiphenyl from the viewpoint of the number of chlorine, and 209 types depending on the substitution position of chlorine.

  On the other hand, research on chemical treatment methods for detoxifying PCBs has been promoted, and at present, a method for dechlorinating PCBs by reacting with sodium metal and converting them into harmless dechlorinated products (hereinafter, “ In Japan, the so-called PCB Special Measures Law was enacted in 2001 against the backdrop of the establishment of a safe disposal method represented by “Metal Sodium Law”. In the meantime, it has become obligatory to dispose of PCB wastes that have been used or stored.

  In the process of dechlorination of PCBs by the metal sodium method, PCBs having a large number of chlorines (hereinafter sometimes referred to as “highly chlorinated PCBs”) undergo a stepwise dechlorination reaction so that the number of chlorines. PCBs (hereinafter sometimes referred to as “low chlorinated PCBs”) having a small amount of C, are finally converted into dechlorinated products from which all chlorine has been eliminated. Therefore, in the metal sodium method, if the dechlorination of high chloride PCBs is insufficient, a large amount of low chloride PCBs may remain in the treated PCB waste.

  Therefore, in the treatment of PCB wastes by the metal sodium method, it is necessary to confirm that PCBs in the PCB wastes are converted to dechlorinated products in the treatment process. In particular, PCB wastes are required to be processed efficiently because of the enormous amount of accumulated waste. Therefore, it is required to quickly confirm this in daily process management. This can be confirmed by measuring the amount (concentration) of PCBs in PCB waste, particularly the amount (concentration) of low-chlorinated PCBs. In this measurement, a highly sensitive analytical method such as gas chromatograph mass spectrometry (GC / MS method) or gas chromatograph electron capture detection method (GC / ECD method) is usually used. Samples collected from PCB wastes require advanced pretreatment to remove interfering components (contaminating components) that affect the measurement results before measurement with an analyzer.

  Such pretreatment is usually performed according to a method described in Non-Patent Document 1 (hereinafter referred to as “official method”). The official method is a pretreatment method suitable for analyzing PCBs having a wide range of chlorine numbers from low chloride PCBs to high chloride PCBs with high accuracy, but dimethyl sulfoxide (DMSO) / hexane distribution, sulfuric acid treatment, Since complicated treatments such as alkali treatment and silica gel column treatment are required, it takes a long time every day to complete, and the cost for its implementation is very high. However, since the amount of PCB waste that has been stored so far is enormous, it is very difficult from the viewpoint of time and economy to proceed with the disposal of PCB waste while performing pre-treatment by the official method.

Thus, various pretreatment methods for PCB-containing samples that replace the official method have been studied.
For example, Non-Patent Document 2 describes a pretreatment method for extracting a sample for measuring dioxins from a sample containing dioxins such as PCDDs, PCDFs, and DL-PCB. In this pretreatment method, An extract obtained by extracting an organic component in the sample with an organic solvent is prepared, and this extract is treated by any of the following methods (a) to (c).
(A) The extract is treated with sulfuric acid and then passed through a silica gel column by a chromatographic technique, and the eluate from the silica gel column is concentrated. Then, this concentrated solution is passed through an alumina column by a chromatographic technique, and then an extraction solvent is supplied to the alumina column, and the eluate is collected.
(B) The extract is passed through a multilayer silica gel column including a silica gel layer, a sulfate silica gel layer, and a silver nitrate silica gel layer by a chromatographic technique, and the eluate from the multilayer silica gel column is concentrated. Then, this concentrated solution is passed through an alumina column by a chromatographic technique, and then an extraction solvent is supplied to the alumina column, and the eluate is collected.
(C) In the method (b), a sulfuric acid silica gel column is used instead of the multilayer silica gel column.

  In these pretreatment methods, some of the contaminant components other than dioxins contained in the extract are silica gel-based columns (that is, the silica gel column of method (a), the multilayer silica gel column of method (b), or the method (c)). It is decomposed when it passes through a (silica gel column), and this decomposition product is captured by the silica gel column. Since the remaining contaminant components pass through the alumina column and the dioxins are captured by the alumina column, when the extraction solvent is supplied to the alumina column and the eluate is collected, the dioxin solution from which the contaminant components are separated (Two types: a solution containing PCDDs and PCDFs and a solution containing DL-PCB) can be obtained, and these can be used as samples for analysis.

  However, in this alternative method, in any of the methods (a) to (c), the time required for the treatment is still a long time of about 1 to 2 days, and the cost for the pretreatment is high. Become. In any of the methods (a) to (c), it is necessary to concentrate the eluate from the silica gel column and the alumina column repeatedly for weight reduction. At this time, low chloride PCBs, particularly chlorine Since PCBs having a number of 1 are likely to dissipate from the eluate together with the solvent, there is a problem that the recovery rate of low-chloride PCBs tends to decrease. Therefore, this alternative method is not suitable as a pretreatment method in the case where measurement of low chloride PCBs is important, such as when PCBs are measured in the process of treating PCB waste by the metal sodium method.

  Patent Document 1 describes a method for extracting PCBs using a multilayer silica gel layer including a silica gel silica gel layer and a silver nitrate silica gel layer and an alumina layer as a pretreatment method for a PCB-containing sample. In this method, an aliphatic hydrocarbon solvent is added to a sulfuric acid silica gel layer that has been partially cooled by heating the sulfuric acid silica gel layer to which a sample containing PCBs has been added to 35 ° C. or higher, and then cooled to room temperature. And the aliphatic hydrocarbon solvent is passed through the silica gel sulfate layer, the silver nitrate silica gel layer, and the alumina layer in this order. Then, by supplying a hydrophobic solvent capable of dissolving PCBs to the alumina layer, the PCBs captured by the alumina layer are extracted.

  However, this extraction method also has a very low recovery rate of low-chlorinated PCBs, especially PCBs having 1 chlorine. Therefore, when extracting PCBs in the process of treating PCB waste by the metal sodium method, Thus, it is not suitable as a pretreatment method when measurement of low chloride PCBs is important.

  In this extraction method, when the metal hydrated silica gel layer is disposed between the sulfuric acid silica gel layer and the silver nitrate silica gel layer, the recovery rate of low chloride PCBs is increased, but the recovery rate is increased when the number of chlorine is 2. Extraction is difficult even for PCBs having up to PCBs and having 1 chlorine.

Appendix 2 of the Ministry of Health, Labor and Welfare Notification No. 192, “Examination Methods for Standards Related to Specially Managed General Waste and Specially Managed Industrial Waste” Japanese Industrial Standard JIS K 0311 (2005), measuring method of dioxins in exhaust gas (6.4.4 and 6.4.5)

International Publication No. 2008/123393 (Claims, specification, page 20, lines 5 to 23)

  An object of the present invention is to enable extraction of PCBs containing low chloride PCBs in a short time from an oily liquid containing PCBs by a simple operation.

  The extraction method according to the present invention relates to a method for extracting polychlorinated biphenyls from an oily liquid containing polychlorinated biphenyls, and is a series of single-layer silica gel layers made of sulfuric acid silica gel and an alumina layer. Step 1 of adding an oily liquid to the silica gel layer of the flow path system, supplying an aliphatic hydrocarbon solvent to the silica gel layer, and passing the aliphatic hydrocarbon solvent through the silica gel layer and the alumina layer in this order. 2 and a step 3 for supplying and passing a hydrophobic solvent capable of dissolving polychlorinated biphenyls to the alumina layer, and a step 4 for securing the hydrophobic solvent that has passed through the alumina layer. In 2, the temperature of the silica gel layer is set to less than 35 ° C.

  In this extraction method, the oily liquid added to the silica gel layer in Step 1 is dissolved in the aliphatic hydrocarbon solvent supplied in Step 2, and passes through the silica gel layer and the alumina layer together with the aliphatic hydrocarbon solvent. At this time, PCBs contained in the oily liquid are trapped in the alumina layer, and other contaminant components other than PCBs are trapped in the silica gel layer, and the remainder passes through the silica gel layer and the alumina layer together with the aliphatic hydrocarbon solvent. To do. For this reason, if the hydrophobic solvent supplied to the alumina layer in Step 3 is secured in Step 4, a hydrophobic solvent solution of PCBs can be obtained.

  In this extraction method, the flow path system includes, for example, a first column filled with a silica gel layer, and a second column filled with an alumina layer and detachable from the first column.

  In general, in this extraction method, in Step 3, it is preferable that a hydrophobic solvent is supplied and passed through the alumina layer in a direction opposite to the passing direction of the aliphatic hydrocarbon solvent. Moreover, it is preferable to remove the aliphatic hydrocarbon solvent remaining in the alumina layer before supplying the hydrophobic solvent to the alumina layer in step 3. Further, in step 3, it is preferable to supply a hydrophobic solvent to the alumina layer while heating the alumina layer to at least 35 ° C.

  The present invention according to another aspect relates to a method for measuring polychlorinated biphenyls contained in an oily liquid containing polychlorinated biphenyls, and this measurement method comprises a single silica gel layer composed of silica gel sulfate, Step 1 of adding an oily liquid to a silica gel layer of a series of flow path systems provided with an alumina layer, supplying an aliphatic hydrocarbon solvent to the silica gel layer, and the aliphatic hydrocarbon solvent as a silica gel layer and an alumina layer Step 2 for passing through in this order, Step 3 for supplying and passing a hydrophobic solvent capable of dissolving polychlorinated biphenyls to the alumina layer, and Step 4 for securing the hydrophobic solvent that has passed through the alumina layer. And step 5 of analyzing the secured hydrophobic solvent by gas chromatography. In step 1 and step 2, the temperature of the sulfuric acid silica gel layer is less than 35 ° C. Set to.

  The present invention according to still another aspect relates to a dechlorination treatment method for polychlorinated biphenyls contained in an oily liquid, and this treatment method dechlorinates polychlorinated biphenyls contained in an oily liquid. The process of converting into a dechlorinated product is included, and the completion time of the said process is judged by measuring polychlorinated biphenyls contained in oily liquid by the measuring method according to the present invention.

  The present invention according to still another aspect relates to a column used for extracting polychlorinated biphenyls from an oily liquid containing polychlorinated biphenyls, and this extraction column is a single-layer silica gel composed of silica gel sulfate. A first column filled with a layer; and a second column filled with an alumina layer detachably connected to one end of the first column.

  Since the method for extracting PCBs according to the present invention includes the steps 1 to 4 described above, PCBs containing low chloride PCBs can be extracted in a short time from an oily liquid containing PCBs by a simple operation. it can.

  In the method for measuring PCBs according to the present invention, since the hydrophobic solvent secured in Step 4 of the extraction method according to the present invention is analyzed by gas chromatography, PCBs contained in oily liquids, particularly low chloride PCBs are analyzed. Can be measured with high accuracy.

  Since the dechlorination treatment method for PCBs according to the present invention determines the completion time of the dechlorination treatment step by measuring the PCBs contained in the oily liquid by the measurement method of the present invention, the low chloride PCB The certainty of dechlorination treatment can be improved.

  Since the column for extracting PCBs according to the present invention includes the first column and the second column described above, it can be used in the extraction method and the measurement method of the present invention.

It is the schematic of an example of the column which can be utilized in the extraction method of PCBs which concerns on this invention. It is a figure which shows 1 process of extraction operation using the said column. It is a figure which shows the other process of extraction operation using the said column. It is a figure which shows the further another process of extraction operation using the said column. It is a figure which shows the further another process of extraction operation using the said column.

  The method for extracting polychlorinated biphenyls (PCBs) according to the present invention relates to a method for extracting PCBs from an oily liquid containing PCBs. The oily liquid from which PCBs are to be extracted is not particularly limited. For example, mineral oils and synthetic oils containing PCBs used in electrical equipment such as transformers and capacitors (usually aliphatic hydrocarbons) In particular, straight chain aliphatic hydrocarbons having about 10 to 15 carbon atoms as the main component), and those in which dechlorination treatment of PCBs by the metal sodium method or the like is being applied or applied Waste organic solvents including PCBs generated in chemical experiments and chemical factories, samples containing PCBs (for example, exhaust gas and incineration ash discharged from incineration facilities, air, soil, industrial wastewater, blood, breast milk and seawater Organic solvents (for example, aliphatic hydrocarbon solvents such as hexane and aromatic hydrocarbon solvents such as toluene) for the analysis of PCBs from river water, lake water, and groundwater. In and the like extracts obtained by extracting the PCB, in particular, in which chlorine atoms may include low chloride PCB such as one PCB compounds.

  With reference to FIG. 1, an example of a column used for implementing the method for extracting PCBs according to the present invention will be described. In the figure, the column 1 mainly includes a first column 10, a second column 20, and a connecting member 30 for connecting both the columns 10, 20, and a series of columns from the first column 10 to the second column 20. A flow path system is formed.

  The first column 10 is formed in a cylindrical shape in which the outer diameter and inner diameter of the lower end 10a are reduced, and has openings 11 and 12 at the upper end and the lower end, respectively. The first column 10 is formed using, for example, glass or plastic having solvent resistance, and is filled with a single silica gel layer 13 made of silica gel sulfate.

The sulfuric acid silica gel used here is prepared by uniformly adding concentrated sulfuric acid to the silica gel surface. On silica gel layer 13, the packing density of the sulfuric acid silica gel is not particularly limited, usually, to set the 0.3~1.1g / cm ³ preferably, 0.5 to 1.0 g / cm ³ It is more preferable to set to.

  The second column 20 is formed in a cylindrical shape and has openings 21 and 22 at the upper end and the lower end, respectively. The second column 20 is formed using, for example, glass or a resin material having solvent resistance and heat resistance, and is filled with a layer filled with alumina, that is, an alumina layer 23. The alumina layer 23 is packed so as to be offset toward the opening 21 side so that a void 24 is formed on the opening 22 side of the second column 20. A similar gap may be provided also on the opening 21 side. Usually, the outer diameter and inner diameter of the second column 20 are preferably set larger than these diameters of the lower end portion 10a of the first column 10, but can also be set to be the same as these diameters of the lower end portion 10a. .

The alumina used in the alumina layer 23 is not particularly limited as long as it can adsorb PCBs, and may be any of basic alumina, neutral alumina, and acidic alumina. Further, the activity of alumina is not limited, and various activities can be used. The packing density of alumina in the alumina layer 23 is not particularly limited, but is usually preferably set to 0.5 to 1.2 g / cm ^3, and set to 0.8 to 1.1 g / cm ³ . More preferably.

  The connecting member 30 is a cylindrical member into which the lower end portion 10a of the first column 10 and the upper end portion of the second column 20 can be inserted, and is stable and heat resistant to various solvents, particularly hydrocarbon solvents. It is formed using a material such as a resin material having solvent resistance and heat resistance. The connecting member 30 removably connects the lower end portion 10a of the first column 10 and the upper end portion of the second column 20. Therefore, in the column 1, the alumina layer 23 portion can be separated from the silica gel layer 13 independently.

  The size of the column 1 can be appropriately set according to the purpose of extracting PCBs from the oily liquid (described later). For example, when the purpose of pretreatment is to extract PCBs from an oily liquid in order to measure the concentration of PCBs contained in the oily liquid, a small or small amount of sample is collected from the oily liquid, and the extraction method of the present invention Therefore, the column 1 can be set to a small size accordingly. On the other hand, in order to efficiently carry out detoxification treatment such as dechlorination treatment and incineration treatment of PCBs contained in a large amount of oily liquid, PCBs contained in oily liquid are dissolved in a small amount of organic solvent. In some cases, it is necessary to process a relatively large amount of oily liquid at a time, so that the column 1 can be set to a large size according to the amount of oily liquid to be processed.

  For example, when PCBs are extracted from a sample of about 1.0 to 500 mg collected from the oily liquid in order to measure the concentration of PCBs contained in the oily liquid, the size of the first column 10 in the column 1 ( The size of the portion that can be filled with the silica gel layer 13 is preferably 10 to 20 mm in inner diameter and 30 to 110 mm in length, and the size of the second column 20 (the size of the portion that can be filled with the alumina layer 23). ) Is preferably an inner diameter of 2.0 to 10.0 mm and a length of 10 to 200 mm.

  Next, a method for extracting PCBs using the above-described column 1 will be described. Here, in order to measure the density | concentration of PCBs contained in an oily liquid, it demonstrates centering on the example in the case of isolate | separating a contaminating component from the said oily liquid, and extracting PCBs.

  In this extraction method, first, as shown in FIG. 2, a solvent container 40 for receiving a later-described aliphatic hydrocarbon solvent that passes through the column 1 is disposed at the lower end of the second column 20.

  Next, a small or trace amount (usually about 1.0 to 500 mg) sample is taken from the oily liquid, and this sample is added to the silica gel layer 13 from the opening 11 at the upper end of the first column 10 (step 1). . At this time, the sample is added to the silica gel layer 13, and a sample, that is, a hydrocarbon solvent that can dissolve the oily liquid and is miscible with the aliphatic hydrocarbon solvent described later is added to dilute the sample. May be. Usually, the hydrocarbon solvent may be added immediately after the sample is added to the silica gel layer 13, or may be added to the sample in advance.

  Next, as shown in FIG. 3, a reservoir 50 for supplying a solvent to the first column 10 is attached to the opening 11 on the upper end side of the first column 10, and the aliphatic hydrocarbon is placed in the reservoir 50. Store the solvent. Then, a pressurizing device 51 for pressurizing the inside of the reservoir 50 is attached, and the inside of the reservoir 50 is pressurized by operating the pump 52. Thereby, the aliphatic hydrocarbon solvent stored in the reservoir 50 is gradually and gradually supplied into the first column 10 (step 2). The aliphatic hydrocarbon solvent supplied from the reservoir 50 into the first column 10 is supplied to the silica gel layer 13 and passes through this layer. Then, the aliphatic hydrocarbon solvent that has passed through the silica gel layer 13 flows from the opening 21 of the first column 10 into the second column 20 through the connecting member 30.

  At this time, PCBs in the sample added to the silica gel layer 13 are dissolved in the aliphatic hydrocarbon solvent and flow into the second column 20 together with the aliphatic hydrocarbon solvent. In addition, some of the various contaminant components contained in the sample are adsorbed and captured by the silica gel layer 13 and held in the first column 10.

  The aliphatic hydrocarbon solvent that has flowed into the second column 20 is supplied to the alumina layer 23 in the second column 20, passes through this layer, is discharged from the opening 22, and is received by the solvent container 40. At this time, PCBs dissolved in the aliphatic hydrocarbon solvent from the first column 10 are captured by the alumina layer 23 and held in the second column 20. In particular, since PCBs are easily captured by the alumina layer 23, they are mainly held near the opening 21 at the upper end in the second column 20. On the other hand, the remaining contaminant components that have flowed to the second column 20 together with the PCBs without being adsorbed and trapped in the silica gel layer 13 pass through the alumina layer 23 together with the aliphatic hydrocarbon solvent, and are received by the solvent container 40.

  The aliphatic hydrocarbon solvent used in this step is capable of dissolving PCBs in the sample, 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 preferable. In general, the storage amount of the aliphatic hydrocarbon solvent in the reservoir 50, that is, the total amount of the aliphatic hydrocarbon solvent supplied to the first column 10 is preferably set to 10 to 120 mL. The supply rate of the aliphatic hydrocarbon solvent from the reservoir 50 is usually preferably set to 0.2 to 5.0 mL / min by adjusting the pressurized state in the reservoir 50 by the pump 52.

  In steps 1 and 2 so far, it is necessary to set the temperature of the silica gel layer 13 to less than 35 ° C., preferably 30 ° C. or less, more preferably 28 ° C. or less. For this reason, when this extraction operation is performed in a high temperature environment and the temperature of the silica gel layer 13 is 35 ° C. or higher, the temperature of the silica gel layer 13 is less than 35 ° C. using a coolant or a cooling device. To control. When the temperature of the silica gel layer 13 is 35 ° C. or more, the low chloride PCBs are easily decomposed or adsorbed by the silica gel layer 13, and the extraction rate (recovery rate) of the low chloride PCBs is lowered. In addition, the lower limit of the temperature of the silica gel layer 13 is not particularly limited as long as the temperature is within a temperature range in which the aliphatic hydrocarbon solvent can be smoothly circulated.

  Next, the second column 20 and the first column 10 are separated by removing the first column 10 from the connecting member 30. Then, as shown in FIG. 4, the second column 20 is turned upside down, and a heating device 60 is disposed around the alumina layer 23. Further, as shown in FIG. 4, a pressurizing device 51 is attached to the opening 22 moved to the upper end side of the second column 20 by upside down. Then, the pump 52 is operated while heating the alumina layer 23 to about 35 to 90 ° C. by the heating device 60, and an inert gas such as nitrogen gas or air is supplied into the second column 20 from the opening 22. As a result, a solvent such as an aliphatic hydrocarbon solvent remaining in the second column 20 is discharged from the opening 21 that has moved to the lower end side of the second column 20 together with the inert gas, and is aliphatic carbonized from the alumina layer 23. A solvent such as a hydrogen solvent is removed. As a result, the alumina layer 23 in the second column 20 is dried. The heating device 60 used here is a heater, a Peltier element, or the like, and can heat the entire alumina layer 23 in the second column 20 to a required temperature.

  In FIG. 4, the second column 20 is displayed with the connecting member 30 attached thereto, but the connecting member 30 may be removed from the second column 20.

  Next, the pressurizing device 51 is removed from the second column 20, and the hydrophobic solvent is supplied and stored in the gap 24 on the opening 22 side that has moved to the upper end side of the second column 20, as shown in FIG. As a result, the hydrophobic solvent is supplied by flowing under its own weight into the alumina layer 23 (step 3).

  The hydrophobic solvent supplied to the alumina layer 23 passes through the alumina layer 23 and is discharged from the opening 21 that has moved to the lower end side of the second column 20. At this time, the hydrophobic solvent dissolves the PCBs captured by the alumina layer 23 and is discharged from the opening 21 together with the PCBs. For this reason, if the hydrophobic solvent discharged | emitted from the opening part 21 is ensured, the hydrophobic solvent solution of PCBs, ie, the extraction liquid of the target PCBs, will be obtained (process 4).

  Here, since the PCBs are mainly captured in the vicinity of the opening 21 side of the alumina layer 23, substantially all of the PCBs captured by the alumina layer 23 are discharged from the second column 20. It is in a state of being mainly dissolved in the hydrophobic solvent in the initial flow portion. Therefore, only by securing the hydrophobic solvent in the initial flow portion discharged from the opening 21, it is possible to obtain the target PCBs extract. Since this extract is composed of the above-described initial flow portion having a small amount, it becomes a small amount that can be easily used in the analysis operation described later. Further, the PCBs extract obtained here is obtained by removing the aliphatic hydrocarbon solvent from the alumina layer 23 and then supplying the hydrophobic solvent to the second column 20. It can be a high-purity extract with little mixing of the hydrogen solvent and contaminating components dissolved therein.

  According to the extraction method according to the present embodiment, the above-described extract can be obtained in a short time of about 0.5 to 1 hour from the work start process (sample addition process to the first column 10).

  In such an extraction step, the alumina layer 23 is preferably supplied with a hydrophobic solvent while being heated by the second heating device 60. Usually, the heating temperature of the alumina layer 23 is preferably set to be at least 35 ° C., and more preferably set to be 60 ° C. or higher. Although the upper limit of heating temperature is not specifically limited, Usually, it is about 90 degreeC. When the alumina layer 23 is heated in this way, the entire amount of PCBs captured by the alumina layer 23 is easily extracted with a smaller amount of the hydrophobic solvent. Therefore, the amount of the PCB extracted solution is used in the analysis operation described later. Easy to set a smaller amount.

  The hydrophobic solvent used in this extraction step is not particularly limited as long as it can dissolve PCBs, but usually toluene, toluene and an aliphatic hydrocarbon solvent (for example, n-pentane, n-hexane). , N-heptane, n-octane, isooctane, cyclohexane etc.) and organic chlorinated solvents (eg dichloromethane, trichloromethane, tetrachloromethane etc.) and aliphatic hydrocarbon solvents (eg n-pentane, n -Hexane, n-heptane, n-octane, isooctane, cyclohexane, etc.). Of these, toluene that can extract PCBs from the alumina layer 23 with a smaller amount of use is preferred.

  When measuring the concentration of PCBs contained in an oily liquid, the extraction liquid obtained in the above-described extraction operation, that is, a hydrophobic solvent solution of PCBs is analyzed by a gas chromatography method as a sample for analysis (Step 5). ). The gas chromatography method can be carried out by using a gas chromatography equipped with various detectors, and is usually a gas chromatograph mass spectrometry method (GC / MS method) or a gas chromatograph with good sensitivity to PCBs. The electron capture detection method (GC / ECD method) is preferred. In particular, according to the GC / MS method, PCBs contained in an analysis sample can be quantified in units of isomers and homologues, so that more knowledge can be obtained from the analysis results.

  In addition, the extract obtained in the above-described extraction operation can be appropriately concentrated and used for analysis by a gas chromatography method when necessary.

  Since the extraction method of the present invention can extract low chloride PCBs, in particular, PCBs having 1 chlorine, at a high recovery rate, the method for measuring PCBs according to the present invention using this extraction method is low chloride. PCBs can be measured with high accuracy. For this reason, the measurement method of the present invention is, for example, a metal sodium method for converting PCBs contained in an oily liquid into a dechlorinated product in order to discard oily liquids such as mineral oil and synthetic oil containing PCBs. In the case of dechlorination treatment such as the above, it can be used for confirming that PCBs are converted into dechlorination products, that is, for judging the completion time of the dechlorination treatment step.

  In this case, in the step of converting PCBs contained in the oily liquid into a dechlorinated product by dechlorination, a part of the oily liquid being treated is collected in a timely manner and the above measurement method is applied. The concentration of PCBs in the medium is measured. And when the measurement result whose PCBs concentration is substantially 0 is obtained, it can be considered that PCBs contained in the oily liquid have been converted into dechlorinated products, and thus the dechlorination treatment step is completed. .

The above-described embodiment can be modified as follows, for example.
(1) In the above-described embodiment, the first column 10 and the second column 20 are detachably coupled by the coupling member 30, but other means can be used for coupling between the columns. . For example, a rubbing portion can be provided at the coupling portion of the columns, and the columns can be detachably coupled by connecting the rubbing portions.

(2) In the above-described embodiment, the aliphatic hydrocarbon solvent stored in the reservoir 50 is supplied to the first column 10 by being pressurized by the pressurizing device 51. However, the aliphatic hydrocarbon solvent in the reservoir 50 is Moreover, it is also possible to let it flow down to the first column 10 naturally without using the pressurizing device 51. The aliphatic hydrocarbon solvent can also be supplied to the first column 10 using a metering pump such as a syringe pump or a suction device. Furthermore, the aliphatic hydrocarbon solvent can also be supplied to the first column 10 by a manual operation using a supply device such as a pipette.

(3) In the above-described embodiment, the hydrophobic solvent supplied to the gap 24 of the second column 20 is naturally supplied to the alumina layer 23 by its own weight, but the opening 21 of the second column 20 or A reservoir for supplying the hydrophobic solvent to the opening 22 moved to the upper end side of the second column 20 by inversion is installed, and the hydrophobic solvent supplied to the reservoir is naturally supplied to the second column 20 by its own weight. It can also be changed. The hydrophobic solvent can also be supplied to the second column 20 using a metering pump such as a syringe pump or a suction device.

(4) In the above embodiment, the second column 20 is separated from the first column 10 when supplying the inert gas or the hydrophobic solvent to the second column 20. It is also possible to change so that an inert gas or a hydrophobic solvent can be supplied to the second column 20 without separation from the one column 10. This can be realized, for example, by connecting the first column 10 and the second column 20 using a connecting device having a flow path switching valve. The flow path switching valve used in this case has an inert gas inlet and a hydrophobic solvent outlet, and is a flow path for connecting the first column 10 and the second column 20. It has a flow path for connecting the inlet of the active gas and the second column 20 and a flow path for connecting the second column 20 and the outlet of the hydrophobic solvent. By switching the flow path, Supply of the aliphatic hydrocarbon solvent from the first column 10 to the second column 20, introduction of the inert gas from the inert gas inlet to the second column 20, and the hydrophobic solvent supplied to the second column 20 Any one of the discharges from the discharge port can be selected.

(5) In the above-described embodiment, the present invention has been described mainly on the case where PCBs are extracted from a sample collected from the oily liquid in order to measure the concentration of PCBs contained in the oily liquid. The invention can also be used for other purposes. For example, oily liquids containing PCBs need to be detoxified by dechlorinating or incinerating PCBs when they are disposed of. It can be difficult to proceed. Therefore, if the extraction method of the present invention is applied to the oily liquid to be disposed of, the PCBs contained in the oily liquid can be converted into a reduced hydrophobic solvent solution, and the PCBs are rendered harmless. It becomes easy to do.

Preparation of Simulated Sample 90% by weight of n-tridecane (hydrocarbon solvent) and 10% by weight of biphenyl were mixed to prepare simulated samples used in the following Examples and Comparative Examples.

Example 1
A column having an inner diameter of 13 mm and a length of 70 mm was filled with 3.8 g of silica gel silica (trade name “Rapiana Sulfate Silica” from Miura Kogyo Co., Ltd.) to a height of 40 mm to prepare a first column. Further, 0.6 g of alumina (trade name “MP Alumina B Super I for Dioxin Analysis” from MP Biomedicals) was packed in a column having an inner diameter of 4.6 mm and a length of 100 mm to a height of 35 mm. Created a column.

  Connect the second column to the lower end of the standing first column, and add 50 μL of the simulated sample 50 mg and the internal standard substance solution for concentration calculation (trade name “EC-5411” from CIL) to the upper end of the first column. Added. Then, 20 mL of n-hexane was supplied to the upper end of the first column at a rate of 2 mL / min, and was discharged from the lower end of the second column (initial step). During the initial step, the temperature of the silica gel layer of the first column was maintained at room temperature (20 ° C.). Then, after the supply of n-hexane is completed, the first column and the second column are separated, and nitrogen gas is supplied in the direction opposite to the passing direction of n-hexane while heating the alumina layer of the second column to 85 ° C. As a result, n-hexane remaining in the second column was removed.

  Next, a hydrophobic solvent was supplied to the second column in the direction opposite to the passing direction of n-hexane, and PCBs captured by the alumina layer of the second column were extracted. Here, the alumina layer was heated to 85 ° C., and toluene was used as the hydrophobic solvent. Further, the supply rate of the hydrophobic solvent was set to 50 μL / min, and 200 μL of the initial flow discharged from the second column was collected as an extract of PCBs. The time required from the start of operation until this extract was obtained was about 0.5 hours.

  The concentration of PCBs was measured for the collected extract. Here, an analytical sample is prepared by adding 50 μL of an internal standard substance solution (CIL's trade name “EC-5415”) for recovery rate calculation to the extract, and this analytical sample is prepared in 1998. The HRGC / LRMS method was used for analysis according to the method described in the “Provisional Manual for Exogenous Endocrine Disrupting Chemical Substances” presented by the Environment Agency in October, and the PCB concentrations were calculated using the method described in the manual.

Example 2
An extraction solution of PCBs was collected in the same manner as in Example 1 except that 50 mg of the simulated sample, 50 μL of the internal standard substance solution for concentration calculation and 0.9 mL of isooctane were added to the upper end side of the first column. The concentration of PCBs was measured in the same manner as in Example 1. The time required for obtaining the PCB extract was about 0.5 hours.

Example 3
50 mg of a simulated sample, 50 μL of an internal standard substance solution for concentration calculation and 0.9 mL of n-hexane were added to the upper end side of the first column, and the heating temperature of the alumina layer at the time of supplying the hydrophobic solvent was changed to 60 ° C. In the same manner as in Example 1 except that n-hexane containing dichloromethane (dichloromethane concentration: 20% by weight) was used as a hydrophobic solvent, an extract of PCBs was collected and the concentration of the PCBs was collected. Was measured in the same manner as in Example 1. The time required for obtaining the PCB extract was about 0.6 hours.

Comparative Example 1
PCBs from simulated samples according to the method described in Schedule 2 of the Ministry of Health and Welfare Notification No. 192, “Testing Standards for Specially Managed General Waste and Specially Controlled Industrial Waste” (ie, the official method explained earlier) A class of analytical samples was prepared. The time required for preparing the sample for analysis was about 3 days. Further, according to the official method described above, the PCB concentration of the prepared analytical sample was measured by the HRGC / HRMS method.

Comparative Example 2
A column with an inner diameter of 13 mm and a length of 70 mm is packed with 0.6 g of silver nitrate silica gel to a height of 10 mm, and 3.8 g of sulfuric acid silica gel (the same as that used in Example 1) is placed on the column. The first column was prepared by further packing to a thickness of 40 mm. In addition, a column having an inner diameter of 4.6 mm and a length of 100 mm was filled with 0.6 g of alumina (the same as that used in Example 1) to a height of 35 mm to prepare a second column.

  50 mg of a simulation sample and 0.90 mL of isooctane were added to the upper end side of the first column which was erected so that the sulfuric acid silica gel layer became an upper layer. After heating the sulfuric acid silica gel layer of this 1st column at 85 degreeC for 30 minutes and cooling to room temperature, the 2nd column was connected with the lower end side of the 1st column. Then, 20 mL of n-hexane was supplied to the upper end of the first column at a rate of 2 mL / min, and was discharged from the lower end of the second column. After completing the supply of n-hexane, the first column and the second column are separated, and nitrogen gas is supplied while heating the second column to 85 ° C., so that the n-hexane remaining in the second column is removed. Removed.

  Next, toluene was supplied to the second column in the direction opposite to the passing direction of n-hexane, and PCBs captured in the second column were extracted. Here, the second column was heated to 85 ° C., the supply rate of toluene was set to 50 μL / min, and 200 μL of the initial flow discharged from the second column was collected as an extract of PCBs. It took about 2 hours from the start of the operation until this extract was obtained. About the extract | collected extract, the density | concentration of the PCBs was measured like Example 1. FIG.

Comparative Example 3
To the upper end of the first column, 50 mg of the simulated sample, 50 μL of the internal standard substance solution for concentration calculation and 0.9 mL of isooctane were added, and the temperature of the sulfuric acid silica gel layer of the first column was 85 by heating during the initial step. Except for the point maintained at 0 ° C., the same procedure as in Example 1 was performed to collect PCB extracts, and the concentration of PCBs was measured in the same manner as in Example 1.

Comparative Example 4
The point that the first column was changed to that used in Comparative Example 2, and 50 mg of the simulated sample, 50 μL of the internal standard substance solution for concentration calculation and isooctane to the upper end side (end side of the sulfuric acid silica gel layer side) of the first column Except for the addition of 0.9 mL, the same procedure as in Example 1 was performed to collect PCB extracts, and the concentration of PCBs was measured in the same manner as in Example 1.

  The operating conditions and the like in Examples 1 to 3 and Comparative Examples 1 to 4 are summarized in Table 1. In addition, with respect to Examples 1 to 3 and Comparative Examples 1 to 4, the recovery rates of PCBs calculated from the measurement results of the PCBs concentration are shown in Table 2. The recovery rates of PCBs shown in Table 2 are based on the internal standard material for calculating the concentration and the internal standard material for calculating the recovery rate.

Claims (8)

A method for extracting said polychlorinated biphenyls from an oily liquid containing polychlorinated biphenyls, comprising:
Adding the oily liquid to the silica gel layer of a series of flow path systems comprising a single layer silica gel layer of silica gel and an alumina layer; and
Supplying an aliphatic hydrocarbon solvent to the silica gel layer, and passing the aliphatic hydrocarbon solvent through the silica gel layer and the alumina layer in this order;
Supplying and passing a hydrophobic solvent capable of dissolving the polychlorinated biphenyls to the alumina layer; and
Securing the hydrophobic solvent that has passed through the alumina layer, and
In step 1 and step 2, the temperature of the silica gel layer is set to less than 35 ° C.
Extraction method of polychlorinated biphenyls.   The said flow path system is provided with the 1st column with which the said silica gel layer was filled, and the 2nd column with which the said alumina layer was filled and which can be attached or detached with respect to the said 1st column. For extracting polychlorinated biphenyls.   3. The method for extracting polychlorinated biphenyls according to claim 1, wherein in step 3, the hydrophobic solvent is supplied to and passed through the alumina layer in a direction opposite to the passing direction of the aliphatic hydrocarbon solvent. .   4. The polychlorinated product according to claim 1, wherein the aliphatic hydrocarbon solvent remaining in the alumina layer is removed before supplying the hydrophobic solvent to the alumina layer in Step 3. Extraction method of biphenyls.   The method for extracting polychlorinated biphenyls according to any one of claims 1 to 4, wherein in step 3, the hydrophobic solvent is supplied to the alumina layer while heating the alumina layer to at least 35 ° C. A method for measuring polychlorinated biphenyls contained in an oily liquid containing polychlorinated biphenyls, comprising:
Adding the oily liquid to the silica gel layer of a series of flow path systems comprising a single layer silica gel layer of silica gel and an alumina layer; and
Supplying an aliphatic hydrocarbon solvent to the silica gel layer, and passing the aliphatic hydrocarbon solvent through the silica gel layer and the alumina layer in this order;
Supplying and passing a hydrophobic solvent capable of dissolving the polychlorinated biphenyls to the alumina layer; and
Securing the hydrophobic solvent that has passed through the alumina layer; and
Analyzing the secured hydrophobic solvent by gas chromatography, and
In step 1 and step 2, the temperature of the sulfuric acid silica gel layer is set to less than 35 ° C.
Method for measuring polychlorinated biphenyls in oily liquids. Including a step of converting polychlorinated biphenyls contained in the oily liquid into a dechlorinated product by dechlorination treatment,
The completion time of the step is determined by measuring the polychlorinated biphenyls contained in the oily liquid by the measurement method according to claim 6.
A method for dechlorination of polychlorinated biphenyls. A column used for extracting the polychlorinated biphenyls from an oily liquid containing polychlorinated biphenyls,
A first column packed with a single layer of silica gel composed of sulfuric acid silica gel;
A second column packed with an alumina layer, detachably connected to one end of the first column;
For extraction of polychlorinated biphenyls.

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