JP2007205927A - Method of manufacturing silica-based filler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a silica-based filler capable of maintaining high adsorption/desorption capability of silica and restraining pressure applied in liquid leakage or venting to a relatively low level. <P>SOLUTION: After passing through a process for adding a template compound to an acid solution for dissolution, then adding water glass for gelling the solution, and forming a silica gel, a process for grinding the silica gel for treatment by a basic solution, or treating the silica gel by the basic solution before crushing, and a process for baking the ground silica gel in the manufacturing method of the silica-based filler; a granular silica-based filler having a double-pore structure, where a through pore that can be separated speedily is introduced to a silica material with the water glass as a raw material, is obtained in addition to a mesopore capable of a high-performance analysis. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a silica-based filler, a silica-based filler produced by such a production method, an analytical pretreatment column filled with such a silica-based filler, and such an analytical product. The present invention relates to a method for separating a substance to be collected using a pretreatment column, a method for purifying a sample, and a method for collecting a substance to be collected.

  In recent years, the influence of trace chemical substances in the environmental atmosphere on human health has been regarded as important, and the demand for measuring these chemical substances is increasing. In the sample collected from the environmental atmosphere, there are a large excess of many foreign substances (coexisting substances). For this reason, in order to perform an accurate analysis, it is necessary to pre-process the analysis sample in advance to reduce the content of contaminants (coexisting substances).

  By the way, in order to reduce various contaminants (coexisting substances), there is a problem that extraction and purification steps are required, and these steps take a long time. Moreover, a part of chemical substances to be analyzed may be removed by these pretreatment steps, and a method for selectively removing only impurities is required. Furthermore, a method has been proposed in which an analyte is selectively adsorbed by using an adsorbent having selective adsorption property to the chemical substance to be analyzed, and then the analyte is eluted with a solvent having a strong extraction power. However, this method has a problem that a large amount of sample is required and the processing takes a long time, particularly when the concentration of the analyte is low.

  Here, as the chemical substance to be analyzed, for example, there are POPs (Persistent Organic Pollutants). These POPs are defined as organic substances that are harmful and adversely affect the environment and human health. Further, PCB (polychlorinated biphenyls), which is one of typical POPs, has many uses because it has stable chemical and physical properties and useful properties. However, because of its toxicity, production was discontinued in 1972 and storage was required, but those in use at that time have been used until their useful life has been reached. Currently, full-fledged PCB processing has started in accordance with the law. In PCB processing facilities, transformers and condensers are dismantled and stored indoors, and in buildings, PCB containing sealants and fluorescent ballasts are damaged or leaked. There is concern about indoor environmental pollution. For this reason, the need for PCB measurement in the environment is increasing.

Non-Patent Document 1 below discloses a measurement manual for dioxins and coplanar PCBs, which are POPs in the ambient air. This measuring method described in Non-Patent Document 1 is called a so-called high volume air sampler method, and is used for sampling a high volume air sampler (for example, HV-500F, HV-1000F (for dioxins) manufactured by Shibata Chemical Co., Ltd.). (Quartz fiber filter paper and polyurethane foam) is attached, and air is collected at a flow rate of 700 L / min for 24 hours or at a flow rate of 100 L / min for 7 days, and the total suction air amount is about 1000 m ³ . To do. This method requires a sampling time of 24 hours or 7 days, and the equipment is expensive and large and complex. When measuring at a plurality of measurement points at the same time or simultaneously measuring a plurality of substances including other POPs. There are many problems such as the need for multiple devices for application to the case of measuring.

  On the other hand, the following Non-Patent Document 2 discloses a low volume using a solid phase extraction column (trade name Sep-Pak (registered trademark) PS Air manufactured by Waters) as a method for monitoring POPs using a relatively simple device. An air sampler method (PSAir-Low-Vol method) has been proposed. In this method, a solid phase extraction column (Sep-Pak (registered trademark) PS Air) is connected to a low volume air sampler (for example, an atmospheric sampling pump SP204-20L manufactured by GL Sciences Inc.), and In this method, air is collected at a flow rate of 2 to 5 L / min over 24 hours. This method is also useful as a method for monitoring PCBs in indoor air (see, for example, Non-Patent Document 3).

However, the PS Air-Low-Vol method proposed by the above-described method for monitoring PCBs in the indoor air stipulates that it takes 24 hours to collect an environment of about 4 m ³ or indoor air. Therefore, the atmospheric flow velocity in the solid phase extraction column is about 3 L / min. As described above, the above method has a drawback that the sampling time becomes long because the atmospheric flow velocity is low. That is, there is no example that discloses a method for quickly sampling harmful substances such as POPs in a liquid or gas using a simple apparatus.

  The PS Air-Low-Vol method is a solid-phase extraction method using a column, and this type of solid-phase extraction method has been actively used in recent years. Conventionally, the liquid absorption method is often used for extracting a sample from a gas, and the liquid-liquid extraction method is used for extracting a sample from a liquid. However, the work is complicated and requires time and experience. There were problems such as using a large amount. On the other hand, the solid-phase extraction method has features that it is easy to work, requires a short time, and uses a small amount of solvent. Therefore, it is very advantageous when a large number of specimens must be processed in a short time, and automation is also easy. In the background of the rapid penetration of solid-phase extraction in recent years, porous particles with good adsorption and desorption performance have been developed, and these have been offered to the market by multiple manufacturers as adsorbents for solid-phase extraction. Can be mentioned. The filler used for solid phase extraction is silica gel or chemically bonded silica gel whose surface is chemically modified as an inorganic base material, and synthesis represented by styrene-divinylbenzene copolymer as an organic base material. Polymers and those obtained by chemically modifying these surfaces are used (for example, see Patent Documents 1 and 2).

  By the way, in order to efficiently adsorb an extremely small amount of residual organic pollutants existing in a large excess of air by using the above-described adsorbent-packed disk or column, the particle diameter of the adsorbent particles is made as small as possible. (For example, trade name GL-Pak PLS series manufactured by GL Sciences, Inc., or trade name Bond Elut series (registered trademark) manufactured by Varian, Inc. can be mentioned. The adsorbent is packed with a particle size of about 40 to 300 μm.) Or by compressing the particles (for example, a trade name Sep-Pak (registered trademark) PS Air manufactured by Waters) Can be listed in the cartridge)), increasing the packing density to make the gap between particles as small as possible preferable. However, in this case, since the pressure applied during ventilation increases, the flow velocity cannot be increased, and it takes a long time to pass a large amount of air.

  On the other hand, high performance liquid chromatography (hereinafter referred to as HPLC) is a method of separating a mixture according to the difference in the moving speed of each substance in a liquid flow using silica gel or polymer gel as a filler. . High performance and high speed separation have been studied as high performance HPLC. In order to achieve high separation, it is preferable to reduce the particle size of the packing material and the dead volume in the column. However, since there are limitations in the apparatus due to an increase in the pressure applied to the column, difficulties in packing, etc., as a compromise between high separation and high speed separation, many of the packing particles are limited to a particle size of about 5 μm. It has become. For example, packing with a small particle size of 1.5 μm or 2 μm has been prepared, but due to the high load pressure, the column length must be shortened or the liquid flow rate must be slowed down. It is hard to say that high performance has been achieved.

  Therefore, double pore silica gel having a micrometer-size through-pore and a nanometer-size mesopore has been developed as a breakthrough of the above-mentioned fine particle-packed HPLC column. This double pore silica gel can control the through-pore diameter and the mesopore diameter independently, and the load pressure can be reduced by increasing the through-pore. By applying this silica gel to the HPLC in the form of rods (one column-shaped lump silica gel of column size), both high-performance separation and high-speed separation are achieved (for example, see Patent Documents 3 and 4). .)

However, no attempt has been made yet to selectively adsorb the above-described minute amount of the target substance to the double pore silica gel, or to remove it outside the system without adsorbing only the minute amount of the target substance.
In addition, the above silica gel is used in a rod shape, and there is a problem that it is weak in mechanical strength. If crushed double pore silica gel can be used, it is thought that productivity will be improved. Furthermore, the rod-shaped double pore silica gel developed so far has a maximum size of about 10 μm as the through-pore size. As is clear from the fact that the particle diameter of the base material for gas collection is about 500 μm, a through-pore of about 10 μm is not sufficient for circulating gas at high speed.

So far, as an attempt to produce silica powder by crushing silica gel, an example in which a silica wet gel is pulverized while passing through a nylon net is known (see Patent Document 5). In addition, by injecting silica sol into an organic solvent through a polymer film having through-holes with a uniform pore diameter, sol emulsion particles are formed in the organic solvent, and then the sol emulsion particles are gelled. Thus, a method for obtaining particulate silica gel is known (see Patent Document 6). However, there have been no reported cases of production by the above method in the production of double pore silica gel using water glass as a raw material.
Ministry of the Environment, Environment Management Bureau General Affairs Division, Dioxin Countermeasures Office, “Air Quality Survey Manual for Dioxins, Section 3 Measurement and Analysis Methods for Dioxins in the Atmosphere” [online], August 2001, Ministry of the Environment, [Heisei Search September 8, 2014], Internet <URL: http: // www. env. go. jp / air / osen / manual / index. html> Takeshi Nakano, 6 others, “Examination of POPs analysis method in the atmosphere”, Abstracts of the 10th Environmental Chemistry Conference, May 23, 2001, p. 472-473 Takeshi Nakano and three others, “Monitoring Method of PCBs in Indoor Air”, Proceedings of the 10th Environmental Chemistry Conference, May 23, 2001, p. 582-583 JP 59-147606 A JP-A-4-334546 JP 2002-362918 A Japanese Patent Laid-Open No. 2003-075420 JP-A-11-268923 JP-A-5-23565

The present invention has been made in view of such a situation, and maintains a high adsorption / desorption capability of silica, and can suppress the pressure applied during liquid passage or ventilation relatively low. It aims at providing the manufacturing method of.
Further, the present invention uses a silica-based filler produced by such a production method, an analytical pretreatment column filled with such a silica-based filler, and such an analytical pretreatment column. It is an object of the present invention to provide a method for separating a substance to be collected, a method for purifying a sample, and a method for collecting a substance to be collected.

The present invention provides the following means.
(1) Add and dissolve the template compound in the acidic aqueous solution and then add water glass to gel the solution, or add and dissolve the template compound in the water glass and then add the acidic aqueous solution to gel the solution. The step of forming silica gel, the silica gel is pulverized and then treated with a basic solution, or the silica gel is treated with a basic solution and then pulverized, and the pulverized silica gel is baked And a method for producing a silica-based filler.
(2) When the silica gel is pulverized, means for pressing and pulverizing silica gel into the through-hole from one side of a porous plate having a plurality of through-holes is used. A method for producing a silica-based filler.
(3) The method for producing a silica-based filler according to (1) or (2), wherein the template compound is any one of polyethylene oxide, polyoxyethylene alkyl ether, and polyacrylic acid. .
(4) A silica-based filler obtained by being produced by the production method according to any one of (1) to (3) above.
(5) The preceding item characterized by comprising a double pore structure having a through pore having a number average diameter of 0.5 μm or more and 25 μm or less and a mesopore having a number average diameter of 2 nm or more and 50 nm or less. 4) Silica-based filler.
(6) The silica-based filler as described in (4) or (5) above, wherein the ratio of the pore volume of the through-pores in the volume is in the range of 30% to 90%.
(7)
The silica-based filler according to any one of (4) to (6), wherein the surface is coated with an organic compound.
(8) The above-mentioned items (4) to (4), wherein the number average particle diameter is in the range of 10 μm or more and 1000 μm or less, and the specific surface area measured by the BET method is 50 m ² / g or more. The silica-type filler as described in any one of 7).
(9) An analytical pretreatment column comprising the silica-based packing material according to any one of (4) to (8).
(10) The analysis sample containing the substance to be separated and the coexisting substance was passed through the analytical pretreatment column described in (9) above, and the substance to be separated was adsorbed on the silica-based filler. A method for fractionating a substance to be fractionated, wherein an eluent is circulated through the pretreatment column for analysis and the substance to be fractionated is allowed to flow out later.
(11) The analysis sample containing the substance to be separated and the coexisting substance is passed through the analytical pretreatment column described in (9) above, and the coexisting substance is adsorbed on the silica-based filler, and A method for separating a substance to be sorted, characterized by causing the substance to be sorted to flow out.
(12) The item (10) or the above item, wherein the substance to be sorted is one or more compounds selected from dioxins, polychlorinated biphenyls, agricultural chemicals, environmental hormones, heavy metals, proteins, and aldehydes (11) The method for separating a substance to be sorted according to (11).
(13) A sample containing the removal target substance and the coexisting substance in the analytical pretreatment column as described in (9) above, and removing the removal target substance from the sample. Purification method.
(14) A recovery characterized in that the sample containing the substance to be collected and the coexisting substance is circulated through the analytical pretreatment column described in (9) above, and the substance to be collected is collected from the sample. Collection method of target substances.

As described above, according to the present invention, by introducing pores (through pores) capable of high-speed separation in addition to pores (mesopores) capable of high-performance analysis in silica materials made from water glass. In addition, while maintaining the high adsorption / desorption ability of the silica material, the pressure applied during liquid passing or aeration can be kept relatively low, and as a result, the liquid passing speed or the aeration speed can be increased. A silica-based filler that can be rapidly pretreated can be obtained.
In addition, when performing analysis and pretreatment of a liquid sample with a column using general particulate silica gel, once bubbles are introduced, the bubbles are difficult to escape. Due to the bubbles, an effective surface area cannot be used, and concentration is performed. It is well known that it leads to a drop in rate. On the other hand, in the case of the particulate silica-based filler having double pores according to the present invention, it is considered that even if bubbles enter, the bubbles are pushed out again with a solvent because of the presence of through pores. All can be utilized and the collection efficiency does not decrease. This is very effective from the standpoint of reproducibility and simplicity, since it is not necessary to take special care to prevent bubbles from entering during the pretreatment.
Therefore, by using an analytical pretreatment column packed with such a silica-based packing material, it is contained in a gas or liquid sample easily, inexpensively, with good reproducibility, while maintaining a rapid and high recovery rate. Processes such as purification, concentration, analysis and fractionation of trace amounts of target substances such as dioxins, polychlorinated biphenyls, agricultural chemicals, environmental hormones, heavy metals, proteins, aldehydes, sample purification, and collection of target substances It becomes.

  Hereinafter, a method for producing a silica-based filler using water glass as a raw material to which the present invention is applied, a silica-based filler, a method for separating a material to be separated, a method for purifying a sample, and a method for collecting a material to be collected are shown in the drawings. Details will be described with reference to FIG.

The silica-based filler according to the present invention can be produced by the following method.
Specifically, first, a water-soluble compound serving as a template is added to an acidic aqueous solution and dissolved. Thereafter, water glass is added and the solution is allowed to stand until the solution gels to form silica (silica gel). Here, the water glass is a thick aqueous solution of alkali silicate obtained by melting silicon dioxide and an alkali such as sodium carbonate, and is a colorless and transparent liquid with strong viscosity. Moreover, after adding the water-soluble compound used as a template to such water glass and dissolving a silica gel, the solution may be gelled by adding an acidic aqueous solution.

  Through pores are formed by this step. That is, a water-soluble compound remains in the silica gel, and this water-soluble compound serves as a template, and a through pore is formed in the silica gel. At this stage, the size of the through pore is determined. That is, the size of the through pores can be determined by controlling the composition of the starting solution and the polymerization rate to control the degree of aggregation of the water-soluble compound.

  In the present invention, an aqueous solution of nitric acid, acetic acid or the like having a concentration of 0.01 M to 1.0 M can be used as the acidic aqueous solution. Moreover, polyethylene oxide, polyoxyethylene alkyl ether, polyacrylic acid and the like having a molecular weight of about 100,000 can be used as the water-soluble compound of the template. The amount of the water-soluble compound added can be, for example, 2% by mass to 15% by mass with respect to the acidic aqueous solution.

  Next, the obtained silica gel is pulverized, washed with water, and further treated with a basic solution. Through this step, dissolution and reprecipitation of the silica skeleton occurs, and mesopores are formed. As the basic solution, an aqueous urea solution, an aqueous ammonia solution, or the like can be used. The obtained silica gel may be washed with water first, treated with a basic solution, and then pulverized. That is, the silica gel may be pulverized before firing. Thus, by pulverizing the silica gel before firing, pore breakage and blockage due to the pulverization treatment can be reduced.

  As a means for pulverizing the silica gel, the silica gel can be pulverized by press-fitting the silica gel into the through-hole from one surface side of the porous plate member having a plurality of through-holes. Examples of the porous plate material include a metal net and a sieve material. The diameter of the through hole is preferably in the range of 30 to 800 μm, more preferably in the range of 100 to 700 μm, and most preferably in the range of 200 to 500 μm. When the pore diameter is 500 μm or less, the particle diameter after firing can be controlled within an appropriate range. Moreover, if the hole diameter is 100 μm or more, the pressure when the gel is pressed into the porous plate can be reduced.

  At this time, when silica gel is pressed from one side of the porous plate, if a dispersion medium is present at the outlet of the porous plate, it can be pulverized by forming micelles in the solvent. As the dispersion medium, any medium that does not uniformly mix with silica gel can be used without particular limitation, and a liquid having low compatibility with water can be preferably used. As the liquid having low compatibility with water, for example, an organic solvent such as hexane, toluene, octanol or the like can be used. If a surfactant is present in the dispersion medium used at this time, the silica gel and the dispersion medium are emulsified, so that they can be uniformly pulverized. As the surfactant, a cationic or nonionic surfactant can be used, and an alkyl sulfonic acid or polyoxyethylene surfactant can be used. Specifically, sodium dodecylbenzenesulfonate, polyethylene glycol alkyl ether, or the like can be used.

  Note that gelation is not completed in a short time, and the start and end of gelation have a certain amount of time. If extrusion is attempted after gelation is completely completed, pressure is applied during extrusion, making extrusion difficult. Therefore, it is more preferable to extrude and form before completely gelling. In addition to the above, as a means for pulverization, a spray drying method, a method using a W / O emulsion, and the like are known (Japanese Patent Laid-Open No. 7-069617), and pulverization may be performed by these means.

  Next, the silica gel is washed with water and then fired (sintered) at a high temperature. As a firing condition of the silica gel, a sintering temperature in the range of 300 ° C. to 600 ° C. for 2 hours to 10 hours can be set. The firing atmosphere is preferably an inert gas such as a nitrogen gas atmosphere. By passing through the above process, the silica type filler which concerns on this invention can be obtained.

  In addition, when it is desired to change the adsorption characteristics of the obtained silica-based filler surface, it is preferable to coat the surface with an organic compound. Examples of the coating method include a monomer adsorption polymerization method (a method in which a monomer is polymerized on the surface of a silica-based filler), a coupling reaction, and the like, but any compound that can chemically react with the silica-based filler is particularly limited. There is no. As the organic compound to be coupled, a chlorosilane compound often used in liquid chromatography is preferable. Examples of chlorosilane compounds include dimethylchlorosilane, trimethylchlorosilane, aminomethyldimethylchlorosilane, dimethoxymethylchlorosilane, dimethylvinylchlorosilane, chloromethyltrimethylsilane, chloromethylmethoxydimethylsilane, chloromethyltrimethoxysilane, allyldimethylchlorosilane, dimethylpropylchlorosilane. Examples thereof include, but are not limited to, 1-chloroethyltrimethylsilane, dimethylisopropylchlorosilane, methylphenylchlorosilane, dimethyloctadecylchlorosilane, tribenzylchlorosilane, dimethylphenylchlorosilane, triphenylchlorosilane, and diphenylmethylchlorosilane.

  In addition to the above coupling reaction, it is possible to react with the silanol part of silica. Examples of such compounds include organometallic compounds, inclusion compounds, proteins, peptides, glycoproteins, glycopeptides, sugars. And so on.

The coupling reaction itself is a known reaction and can be performed using a general method. For example, the method described in Reference Document 1 below can be used. That is, in the absence of moisture, pyridine and a silane coupling agent are added in toluene as a solvent and reacted by heating under reflux. Further, after the washing and drying, an end capping reaction may be optionally performed.
“Reference 1”
Japanese Patent Laid-Open No. 2002-22721

  As shown in FIG. 1, an analytical pretreatment column 1 which is an example of this embodiment has a silica-based filler 2 according to the present invention in a syringe barrel (reservoir) which is a column container 3 as a filler layer 2a. It is configured by filling. Filters (not shown) are attached above and below the filler layer 2a.

  A sample such as liquid or gas is flowed through the pretreatment column for analysis 1 and the target substance contained in the sample is once adsorbed and extracted, or the coexisting substance is adsorbed and the target substance is allowed to flow out. Can be collected and recovered. In addition, the sample can be purified.

  The shape of the column container 3 (reservoir) is not particularly limited. It may be a normal cylindrical shape or a disk shape. The column container 3 can be appropriately sized according to the analysis throughput. Usually, a volume of about 0.1 to 100 ml, preferably about 3 to 6 ml is suitable in terms of handling. The material of the column container 3 (reservoir) is preferably made of glass, stainless steel, or resin (for example, polypropylene or polyethylene), is insoluble in the solvent used, and the silica-based filler 2 is being concentrated in the sample. The material and shape of the column container 3 are not particularly limited.

  The silica-based filler 2 according to the present invention has a particle shape, and its number average particle diameter is preferably in the range of 10 μm to 1000 μm, more preferably in the range of 30 μm to 700 μm, and more preferably in the range of 50 μm to 500 μm. A range is most preferred. When the average particle size is less than 10 μm, when the flow rate of an analysis sample such as liquid or gas flowing through the column 1 is increased, the difference in static pressure before and after the filler layer 2a made of the silica-based filler 2 (pressure loss) ) Becomes large, and the analysis sample cannot flow at a high flow rate. On the other hand, if the average particle diameter exceeds 1000 μm, the adsorption efficiency of the target substance is deteriorated. In addition, the average particle diameter of the silica-type filler 2 is measured based on the JIS Z8815 sieving test method general rule using the test sieve defined in JIS Z8801.

The silica-based filler 2 according to the present invention may be modified (coated) with an organic compound for controlling the surface adsorptivity, or may be unmodified (coated) at all.
In addition, the column container 3 may be filled with the above-mentioned silica-based filler 2 and another filler, if necessary, and a multilayer structure composed of the silica-based filler 2 and another filler or base material. It may be filled so as to form.
In addition, the silica type filler 2 which concerns on this invention can also be used in combination with things other than particle shape.

  In the analytical pretreatment column 1 of the present invention, in addition to the silica-based filler 2, a normal filler such as polystyrene beads, ODS, or alumina beads can be used in combination. That is, the particles of the silica-based filler 2 and the particles or fibers of the normal filler can be mixed or packed into the column container 3 in layers.

The specific surface area of the silica-based filler 2 according to the present invention is preferably 50 m ² / g or more, and more preferably 100 m ² / g or more. When the specific surface area is less than 50 m ² / g, the adsorption efficiency of the target substance is deteriorated, which is not preferable. The specific surface area is measured by the BET method.

  The silica-based filler 2 according to the present invention uses the above-mentioned water glass as a silica source, and has a number average diameter of 0.5 μm to 10 μm and a through-pore having a number average diameter of 2 nm to 50 nm. It is more preferable to have a double pore structure in which the mesopores of each other are interconnected and have a three-dimensionally expanded pore structure. The through pores are a large number of through holes penetrating the inside of the filler, and the mesopores are a large number of pores formed on the surface of the filler or the wall surface of the through pore.

  The number average diameter of the through pores is preferably in the range of 0.5 μm to 25 μm, more preferably in the range of 0.5 μm to 10 μm, and particularly preferably in the range of 0.5 μm to 7 μm. When the number average diameter of the through pores is less than 0.5 μm, the difference in static pressure (pressure loss) before and after the filler layer 2a increases when the flow rate of the analysis sample such as liquid or gas flowing through the column 1 is increased. This is not preferable because the analysis sample cannot flow at a high flow rate. On the other hand, if the number average diameter of the through pores exceeds 25 μm, the porosity of the silica-based filler 2 itself increases, and the physical strength of the silica-based filler 2 cannot be maintained, which is not preferable.

  The proportion of the pore volume of the through pores in the volume of the silica filler 2 is preferably in the range of 30% to 90%, more preferably in the range of 40% to 85%, and more preferably in the range of 50% to 80%. The range of is more preferable. When the pore volume ratio of the through pores is less than 30%, the difference in static pressure (pressure loss) before and after the filler layer 2a is large when the speed of the analysis sample such as liquid or gas flowing through the column 1 is given. This is not preferable because the analysis sample cannot flow at a high flow rate. On the other hand, if the ratio of the pore volume of the through pores exceeds 90%, the porosity of the silica-based filler 2 itself is increased, and the physical strength of the silica-based filler 2 cannot be maintained, which is not preferable.

  Further, the ratio of the pore volume of the through pore to the volume of the silica filler 2 can be obtained from the product of the density of the silica filler 2 and the pore volume of the through pore per mass of the silica filler 2. it can. On the other hand, the density of the silica-based filler 2 is obtained by dividing the total volume of the silica-based filler 2 including the through-pore and mesopore pore volumes by the mass of the silica-based filler 2. On the other hand, the pore volume of the through pore per mass of the silica-based filler 2 can be obtained by a mercury intrusion method.

  The number average diameter of the mesopores is preferably 2 nm to 50 nm, more preferably 5 nm to 40 nm, and particularly preferably 8 nm to 35 nm. If the number average diameter of the mesopores is less than 2 nm, the substance to be adsorbed cannot enter the mesopores and is difficult to be adsorbed, resulting in a decrease in the recovery rate. On the other hand, if the number average diameter exceeds 50 nm, it is not preferable because it is not sufficiently adsorbed.

The analytical pretreatment column 1 of the present invention can be used, for example, as follows.
As shown in FIG. 2, an analytical pretreatment column 1 filled with a silica-based filler 2 is prepared, and a sample 11 is caused to flow down to the analytical pretreatment column 1. The sample 11 contains a substance 12 to be sorted and a coexisting substance 13 that is not to be sorted. When the sample 11 is caused to flow down, the fractionation target substance 12 is adsorbed by the silica-based filler 2, and the coexisting substance 13 that is not subject to fractionation is allowed to flow down without being adsorbed. Thereafter, the eluent is flowed down to desorb the separation target substance 12. In this way, the sorting target substance 12 contained in the sample 11 can be sorted.

  Further, as shown in FIG. 3, an analytical pretreatment column 1 filled with a silica-based filler 2 is prepared, and a sample 11 is caused to flow down to the analytical pretreatment column 1. When the sample 11 is caused to flow down, the coexisting substance 13 that is not to be sorted is adsorbed by the silica-based filler 2, and the substance to be sorted 12 is caused to flow down without being adsorbed. In the flowed-down solution, the amount of the coexisting substance 13 is greatly reduced, while the sorting target substance 12 almost flows out as it is. In this way, the sorting target substance 12 contained in the sample 11 can be sorted.

  When the target substance 12 is adsorbed on the silica-based filler 2 or not adsorbed, it can be controlled by, for example, appropriately selecting an organic compound to be coated on the surface of the silica-based filler 2.

  The adsorption target substance of the analytical pretreatment column 1 of the present invention is a compound that accumulates in humans or livestock and causes toxicity, a compound excreted in urine of humans or livestock, and its metabolites, or useful for humans or livestock Compounds, environmental pollutants, poisons, physiologically active substances and the like. Specific examples include dioxins, polychlorinated biphenyls, agricultural chemicals, environmental hormones, petrochemical derivatives, nutritional components and metabolites thereof, products from microorganisms, toxins, heavy metals and metabolites thereof. Examples of these compounds include aldehydes, dioxins, dibenzofurans, polycyclic aromatic hydrocarbons (including PAHs and benzo (a) pyrene), polychlorinated biphenyls, polybrominated biphenyls, DDT, chlorpyrifos, aldrin, dieldrin, Endrin, Chlorden, Heptachlor, Trichlorobenzene, Tetrachlorobenzene, Hexachlorobenzene (HCB), Milex, Toxaphene (Camfechlor), Hexachlorocyclohexane (Lindene (γ-HCH), etc.), Chlordecone (Kepon), Octachlorostyrene (OCS), Ashram, simazine, 1,4-dioxane, nonylphenol, surfactant, female hormone, male hormone, other hormones, polyphenols, antibiotics, antibacterial agents, proteins, peptides Lipids, sugars, nucleic acid-related substance, vitamins, neurotransmitters, natural toxins typified by mycotoxins and marine toxins, arsenic, selenium and although the like these metabolites, it is not particularly limited thereto.

Although the method for separating the target substance has been described above, in the present invention, the above-described sorting method can be directly applied to the method for removing the target substance from the sample and the method for collecting the target substance.
In addition, specific uses of the analytical pretreatment column 1 of the present invention include incinerator exhaust gas, exhaust gas from various manufacturing facilities, ambient air such as air collected on highways, indoor air, factory wastewater, river water These are trace substances selected from lake water, excrement from human bodies and livestock, and include, but are not limited to, pretreatment that requires high concentration.

As described above, according to the analytical pretreatment column 1 of the present embodiment, a through-pore capable of high-speed separation is formed in addition to a mesopore capable of high-performance analysis on a silica material made from water glass. Therefore, while maintaining the high adsorption / desorption capability of the silica material, the pressure applied during liquid flow or aeration can be kept relatively low, the selectivity to the target substance is increased, and the processing time is shortened. Can be achieved.
Therefore, by using the analytical pretreatment column 1 packed with such a silica-based filler 2, it can be easily and inexpensively in a gas or liquid sample while maintaining a high reproducibility with good reproducibility. Processes such as purification, concentration, analysis, and fractionation of trace amounts of target substances, sample purification, and recovery of target substances are possible.

  Hereinafter, the effects of the present invention will be made clearer by examples. In addition, this invention is not limited to a following example, In the range which does not change the summary, it can change suitably and can implement.

Example 1
<Synthesis of silica-based filler>
As an acidic aqueous solution, 1.2 g of polyethylene oxide (molecular weight Mv = 100,000, manufactured by Aldrich) as a template was added to 20 g of 1M nitric acid aqueous solution and dissolved. Next, 1.0 g of sorbitol (manufactured by Wako Pure Chemical Industries, Ltd.) was added and dissolved, and then cooled in an ice bath. Furthermore, 14 g of water glass (52-57%, manufactured by Wako Pure Chemical Industries, Ltd.) was added with vigorous stirring under ice cooling. Further, after stirring for 30 minutes under ice-cooling, 2 mL of the solution was transferred to a cylindrical container having an inner diameter of 12 mm and allowed to stand in a thermostat at 60 ° C. About 2 hours after standing, the water glass gelled and became solid.
Next, the solidified cylindrical gel was pulverized by being extruded from a stainless steel net having an opening diameter of 300 μm defined in JIS8801. The crushed gel was washed by standing in pure water (ion exchange water) for 8 hours, and then the pure water was discharged, and then the gel was put into a 100 mL autoclave, and 70 mL of 1.5 M urea aqueous solution was added. . After standing for 2 hours, the temperature was raised to 110 ° C. over 3 hours and then aged for 5 hours. After cooling, the gel was taken out and washed by leaving it in pure water for 8 hours.
Next, after draining pure water, the gel was transferred to a crucible, heated to 600 ° C. in 2 hours, and sintered at 600 ° C. for 2 hours to decompose and remove polyethylene oxide. In this manner, a particulate silica-based filler having a double pore structure having a structure in which a skeleton having mesopores and through-pores was entangled was obtained.
About the obtained silica type filler, the BET specific surface area, the number average diameter of the mesopores, the number average diameter of the through pores and the pore volume were measured. The BET specific surface area and the number average diameter of mesopores were measured by BET method using ASAP2000 manufactured by Micrometrics. Further, the number average diameter and pore volume of the through pores were measured by a mercury intrusion method using a porosimeter series 200 manufactured by Carlo Elba. The measurement results are shown in Table 1.

  Next, the resulting silica gel was subjected to a silane coupling reaction to introduce octadecyl groups on the silica surface. Specifically, 1.58 g of silica gel washed with hydrochloric acid was dispersed in 15 mL of dry toluene, and 2.0 g of dimethyloctadecylchlorosilane (manufactured by Shin-Etsu Chemical Co., Ltd.) and 0.6 g of pyridine (manufactured by Junsei Chemical Co., Ltd.) were added. Heated to reflux for 6 hours. Thereafter, the silica gel was sequentially washed with 5 mL of toluene, 50 mL of methanol, 50 mL of methanol containing 20% water, and 20 mL of chloroform. The obtained silica gel was vacuum-dried at 130 ° C. for 4 hours to obtain a silica gel into which an octadecyl group was introduced. This silica gel was classified to prepare the silica-based filler of Example 1 having an average particle diameter of 380 μm.

<Preparation of analytical pretreatment column>
The analytical pretreatment column of Example 1 was manufactured by filling 300 mg of the silica-based filler in a cylindrical column container (reservoir) having an inner diameter of 12 mm and an internal volume of 6 mL, to which a polyethylene filter was attached at the bottom.

(Comparative Example 1)
A rod-shaped silica-based filler having a double pore structure was prepared in the same manner as in Example 1 except that the solidified cylindrical gel was not extruded from the stainless steel net and was subjected to the subsequent treatment in the form of a rod. Got. The rod-shaped silica filler was pulverized in a mortar to obtain a particulate silica filler of a comparative example. About the obtained silica type filler, the BET specific surface area, the number average diameter of the mesopores, the number average diameter of the through pores and the pore volume were measured. The measurement results are shown in Table 1.
Next, the silica gel into which the octadecyl group was introduced was obtained in the same manner as in Example 1, and then the reservoir was filled, whereby the analytical pretreatment column of Comparative Example 1 was produced.

<Evaluation of physical properties of silica-based fillers of Examples and Comparative Examples>
As shown in Table 1, the silica-based fillers of Example 1 and Comparative Example 1 both have a number average diameter of the through pores in the range of 2 to 25 μm or less, and the number average diameter of the mesopores in the range of 6 to 15 nm. there were.
Next, when Example 1 and Comparative Example 1 are compared, it can be seen that the pore volume of the through pore is larger in Example 1. This is because when the silica-based filler of Example 1 is produced, the gel containing the template compound is extruded through a mesh and pulverized, and through-holes are formed by sintering after pulverization. This is because there is no risk of cracking and reduction.

<Additive recovery test of indicator compound>
Using the analytical pretreatment columns of Example 1 and Comparative Example 1, an indicator compound addition recovery test was conducted. As an indicator compound, phenol having high hydrophilicity and difficult to recover was selected, and a 10 g / L aqueous solution was prepared as a standard solution. 20 μL of this standard solution was collected with a microsyringe and added to water, and the pH was adjusted to 3.5 with 6N hydrochloric acid to prepare 1 L of test water.
The obtained test water (100 mL) was poured into the analytical pretreatment columns of Example 1 and Comparative Example 1 and allowed to flow down. The condition of the linear velocity during the flow of the test water was 10 ml / min. Next, 3 mL of methanol was allowed to flow down to each column as an eluent, and the effluent was collected in an eggplant flask. The recovered effluent was quantitatively analyzed by the HPLC method, the amount of phenol contained in the same solution was quantified to determine the recovery amount, and the addition recovery rate of phenol was determined from this result.

  As shown in Table 2, Example 1 was able to recover phenol at a higher recovery rate than Comparative Example 1. From this result, the analytical pretreatment column of the example is more useful for recovering phenol in water.

FIG. 1 is a cross-sectional view showing an example of a pretreatment column for analysis to which the present invention is applied. FIG. 2 is a schematic diagram for explaining an example of an organic substance concentration method using the analytical pretreatment column shown in FIG. FIG. 3 is a schematic view for explaining another example of the organic substance concentration method using the analytical pretreatment column shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Analytical pretreatment column, 2 ... Silica-type packing material, 2a ... Packing material layer, 3 ... Column container (reservoir)

Claims (14)

By adding and dissolving a template compound in an acidic aqueous solution and then gelling the solution by adding water glass, or by adding an acidic aqueous solution after dissolving and adding the template compound to water glass, Forming a silica gel;
Crushing the silica gel and then treating with a basic solution, or treating the silica gel with a basic solution and then crushing; and
And a step of baking the pulverized silica gel.   2. The silica-based filler according to claim 1, wherein when the silica gel is pulverized, means for pressing and pulverizing silica gel into the through-holes from one side of a porous plate having a plurality of through-holes is used. Manufacturing method.   The method for producing a silica-based filler according to claim 1 or 2, wherein the template compound is any one of polyethylene oxide, polyoxyethylene alkyl ether, and polyacrylic acid.   A silica-based filler produced by the production method according to any one of claims 1 to 3.   5. The double pore structure having a through pore having a number average diameter of 0.5 μm or more and 25 μm or less and a mesopore having a number average diameter of 2 nm or more and 50 nm or less. Silica-based filler.   The silica-based filler according to claim 4 or 5, wherein the ratio of the pore volume of the through-pores in the volume is in the range of 30% to 90%.   The silica-based filler according to any one of claims 4 to 6, wherein the surface is coated with an organic compound. The number average particle diameter is in the range of 10 μm or more and 1000 μm or less, and the particle shape has a specific surface area measured by the BET method of 50 m ² / g or more. The silica-based filler according to item.   A pretreatment column for analysis, which is packed with the silica-based filler according to any one of claims 4 to 8.   The analysis sample containing the substance to be separated and the coexisting substance is circulated through the analytical pretreatment column according to claim 9, and after the substance to be separated is adsorbed to the silica-based filler, the analysis is performed. A method for fractionating a substance to be sorted, characterized in that an eluent is circulated through a pretreatment column for use to cause the substance to be sorted to flow out.   An analysis sample containing the substance to be separated and the coexisting substance is circulated through the analytical pretreatment column according to claim 9 so that the coexisting substance is adsorbed on the silica-based filler, and the substance to be separated is collected. A method for sorting a substance to be sorted, characterized in that   The said fractionation object substance is 1 type, or 2 or more types of compounds chosen from dioxin, polychlorinated biphenyl, an agricultural chemical, an environmental hormone, heavy metal, protein, and aldehydes, The Claim 10 or 11 characterized by the above-mentioned. Sorting method of substances to be sorted.   A sample purification method, wherein a sample containing a substance to be removed and a coexisting substance is circulated through the analytical pretreatment column according to claim 9 to remove the substance to be removed from the sample.   A sample containing the substance to be collected and the coexisting substance is circulated through the analytical pretreatment column according to claim 9, and the substance to be collected is collected from the sample. Method.

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