KR101214940B1

KR101214940B1 - The manufacturing method of silica monolithic particles and silica monolithic particles using same

Info

Publication number: KR101214940B1
Application number: KR1020100098415A
Authority: KR
Inventors: 정원조; 이승미; 이주영
Original assignee: 인하대학교 산학협력단
Priority date: 2010-10-08
Filing date: 2010-10-08
Publication date: 2012-12-24
Also published as: WO2012047075A3; KR20120036636A; WO2012047075A2

Abstract

The present invention relates to a method for preparing silica monolith powder and thus to silica monolith powder, more specifically to preparing silica monolith (step 1); Powdering the silica monolith prepared in step 1 (step 2); And igniting the silica monolit prepared in step 2 (step 3).
According to the present invention, the process is simplified as it does not need to perform the steps of washing and classifying the particle size as compared to the conventional method for producing silica monolith powder, and as the process is simplified, the cost of manufacturing is reduced. have. In addition, while reducing the size of the monolit particles, there is an effect that the pore (pore size) becomes large. Therefore, when the silica monolith according to the present invention is used as the stationary phase of the liquid chromatography, the resolution is increased, while the pressure applied to the column is reduced, thereby increasing the efficiency of the liquid chromatography.

Description

The manufacturing method of silica monolithic particles and silica monolithic particles using same

The present invention relates to a method for producing silica monolith powder and to silica monolith powder produced thereby.

Generally, porous powder is mainly used as a stationary filler in liquid chromatography, and silica (SiO ₂ ), alumina (Al ₂ O ₃ ), zirconia (ZrO ₂ ) powder, and various ligands on the porous surface of the powder are used. Chemically bonded or polymer coated ones are used, and various types of block copolymer porous polymer powders are also used. Currently, the most common filler is a C ₁₈ stationary phase in which an octadecyl ligand is bound to a porous silica powder. However, monoliths have recently been of great interest in the areas of liquid chromatography (LC) and capillary electrochromatography (CEC).

Monolit means that the stationary phase is one giant three-dimensional porous network. Monolit columns do not require frits because the stationary phase itself acts as a frit, and because of their high porosity, they are less efficient at higher flow rates and have a faster mass transfer rate. This is high, there is an advantage that the manufacturing cost is reduced compared to the conventional packed column. Because of these advantages, monolithic columns of 2 to 5 mm in diameter and 10 to 30 cm in length are already commercially available.

The monoliths are in the spotlight especially in the field of microcolumn chromatography and capillary electrochromatography. In microcolumn chromatography and capillary electrochromatography, frits with a very small void volume should be used. The formation and mounting of such frits is not only very difficult, but also causes many problems such as bubble formation. Is a porous net structure and at the same time interest in monolit with a frit function is increasing, and research on this is being actively conducted. However, the reproducibility of the monolithic column is not yet complete, and the commercialization step of the microcolumn or capillary electrochromatography column is delayed somewhat.

There are two types of monoliths for microcolumn or capillary electrochromatography columns: inorganic polymers and organic polymers. In general, a monomer mixture, a polymerization catalyst, and a solvent which does not dissolve the resulting polymer are mixed to form a solution. After polymerization, the polymerization is carried out by raising the temperature, and finally, by washing off the solvent and the unreacted monomer. Inorganic polymer monoliths are predominantly silica type (Bartle et al . , J. Chromatogr . A , 2000 , 892, 279-290; Tang et al., J. High Resolut . Chromatogr . , 2000 , 23, 73), the organic polymer type is a styrene-divinylbenzene-based copolymer (Gusev et al . , J. Chromatogr.A , 1999 , 855, 273-290), methacrylate System copolymers (Peters et al . , Anal . Chem . , 1988 , 70, 2296; Coufal et al . , J. Chromatogr. A. , 2002 , 946, 99-106), acrylamide copolymers (Fujimoto et al., J Chromatogr. A. , 1995 , 716, 107; Hoegger et al., J. Chromatogr . A. , 2001 , 914, 211-222).

The monolith may be variously prepared in a stationary phase through a modification reaction in which the monolith is first prepared and then attached again to the ligand. The ligands include C ₁₈ ligands (Minakuchi et al . , Anal . Chem . , 1996 , 68, 3498-3501; Minakuchi et al . , J. Chromatogr . A. , 1997 , 762, 135-146; Ishizuka et al . , J. Chromatogr. ., 2002, 960, 85-96), polar or ionic ligands for ligand exchange (Suzuki, etc., J. Chromatogr. A., 2000, 873, 247-256), Ch Lyon chiral ligand (Chen, etc., Anal.Chem. , 2001 , 73, 3348-3357; Chen et al . , J. Chromatogr.A . , 2002 , 942, 83-91). One unusual monolit is one in which a silica capillary is filled with a powdery stationary phase, followed by sintering the entire stationary phase with a cyclic heating line (Adam et al . , J. Chromatogr . A. , 2000 , 887, 327-337).

However, since monolith tends to shrink during manufacturing, it is not possible to make a column directly in a stainless steel tube, but to make a monolith first and then shrink the tube by putting a monolith in a teflon tube that shrinks by heating. There are limitations to be prepared (Majors, LC - GC , 2000 , 18, 586-598). Monolithic columns also end up immediately if some of their columns (mainly inlets) become blocked or broken.

Furthermore, since a series of processes such as washing of unreacted material after monolith production, ligand addition reaction, endcapping reaction, and additional washing process are inefficient, a lot of time and effort are consumed.

Therefore, the inventors of the present invention have better resolution than the liquid chromatography stationary phase using silica, and during the research to solve the problem of the conventional monolit column, after preparing the monolit through a polymerization reaction, it is pulverized into fine powder and It was confirmed that the stationary phase of the high performance liquid chromatography prepared by attaching the ligand after the washing process and the ignition process can improve the resolution and solve the bulk monolith column problem. Filed. However, there is a problem in that the method includes industrially expensive processes such as a washing process using a large amount of solvent and a sifting process for selecting only the required particle size.

Therefore, the present inventors precisely control the mixing ratio of the raw materials to make the silica monolit, and by combining the heating reaction process consisting of several steps as appropriate to produce a monolit, after the monolit is powdered, the solvent washing and sifting process Without a simple heat treatment process, a method for producing a suitable size of silica monolit powder has been developed.

It is an object of the present invention to provide a method for producing silica monolit powder.

Another object of the present invention to provide a silica monolit powder prepared by the above method.

In order to achieve the above object, the present invention comprises the steps of preparing a silica monolit (step 1); Powdering the silica monolith prepared in step 1 (step 2); And it provides a method for producing a silica monolith powder, comprising the step (step 3) of igniting the silica monolit prepared in step 2.

In addition, the present invention provides a silica monolith powder prepared by the method for preparing the silica monolith powder.

According to the present invention, the process is simplified as it does not need to perform the steps of washing and classifying the particle size as compared to the conventional method for producing silica monolith powder, and as the process is simplified, the cost of manufacturing is reduced. have. In addition, while reducing the size of the monolit particles, there is an effect that the pore (pore size) becomes large. Therefore, when the silica monolith according to the present invention is used as the stationary phase of the liquid chromatography, the resolution is increased, while the pressure applied to the column is reduced, thereby increasing the efficiency of the liquid chromatography.

1 is an optical micrograph of the silica monolit powder particles of Example 1,
2 is a chromatogram obtained from a column packed with a C18 attached stationary phase prepared from the silica monolit powder of Example 1,
3 is an optical micrograph of the silica monolit powder particles of Example 3,
4 is a SEM photograph of a stationary phase with polystyrene prepared from the silica monolit powder of Example 3,
5 is a chromatogram obtained from a column packed with a polystyrene stationary stationary phase prepared from the silica monolit powder of Example 3,
6 is an optical micrograph of the silica monolit powder prepared in Example 5,
7 is a chromatogram obtained from a column packed with a C18 attached stationary phase prepared from the silica monolit powder of Example 5. FIG.

Hereinafter, the present invention will be described in detail.

The present invention,

Preparing a silica monolit (step 1);

Powdering the silica monolith prepared in step 1 (step 2); And

It provides a method for producing a silica monolith powder, comprising the step (step 3) of igniting the silica monolit prepared in step 2.

Hereinafter, the present invention will be described in detail step by step.

Step 1 according to the present invention is to prepare a silica monolit,

Mixing 60 to 80% by weight of TAOS, 10 to 40% by weight of water-soluble porogen and 0 to 25% by weight of blowing agent (step a);

Stirring by adding 55-80 wt% of 0.002-0.1 N acid aqueous solution to 20-45 wt% of the mixture mixed in step a (step b);

Heating the mixture to which the acid of step b is added at 40 to 80 ° C. for 12 to 60 hours (step c);

Heating the product of step c to another temperature in the range of 70-150 ° C. twice (step d).

Step a is a step of mixing 60 to 80% by weight of TAOS, 10 to 40% by weight of water-soluble porogen and 0 to 25% by weight of blowing agent. First, TAOS serves as a monomer for constituting silica, and is selected from the group consisting of tetramethylorthosilicate (TMOS), tetraethylorthosilciate (TEOS), and tetrabutylorthodsilicate (TBOS). It is preferable that it is 1 type, and it is preferable to contain 60-80 weight%. If the content of the TAOS is less than 60% by weight, there is a problem that the resulting monolithic structure is not dense. If it exceeds 80% by weight, the reaction rate is slow and the monolithic structure is too dense.

In step a, the water-soluble porogen is preferably included in 10 to 40% by weight. The porogen is a solvent which does not dissolve the produced polymer, and the water-soluble porogen is a group consisting of polyethylene glycol (polyethleneglycol, PEG), polypropylene glycol (PPG), and polyvinyl alcohol (polyvinylalchohol, PVA). It is preferable that it is 1 type chosen from. If the content of the water-soluble porogen is less than 10% by weight or contains more than 40% by weight there is a problem that the crevice structure of the resulting monolith is too large or too small.

Preferably, the foaming agent in step a comprises 0 to 25% by weight. The blowing agent serves to form pores in the silica monolit, and the blowing agent is selected from the group consisting of urea, azobisisobutyronitrile (AIBN) and toluenesulfonylhydrazide (TSG). It is preferable that it is 1 type selected. Even if the blowing agent is not used, the monolith includes pores to some extent, and when the content of the blowing agent exceeds 25% by weight, too many pores are formed, resulting in a weak monolit structure.

The step b is a step of stirring by adding 55 ~ 80% by weight of 0.002 ~ 0.1 N acid aqueous solution to 20 ~ 45% by weight of the mixture mixed in the step a. The aqueous acid solution acts as a catalyst, preferably acetic acid, but is not limited to silica monolit if it can be produced.

Step c is a step of heating the mixture to which the acid of step b is added to 40 ~ 80 ℃ for 12 to 60 hours. The heating method is not particularly limited, but it is preferable to use an oven. This stage produces a monolith that is somewhat hardened.

The step d is a step of heating the product of the step c in the range of 70 ~ 150 ℃ in two times, the temperature of the second process is different and can be changed in various ways depending on the heating vessel environment and the desired physical properties of the product. . This process can be performed in an oven or autoclave. Silica monoliths prepared by heating with an autoclave tend to have large pupil sizes. As the polymerization progresses, the monolit shrinks, which can be easily removed from the container.

Step 2 according to the present invention is a step of powdering the silica monolit prepared in step 1. The method of powdering the silica monolit is not particularly limited, and may be ground to a fine powder using a ball mill or agate mortar and pestle.

Step 3 according to the present invention is a step of heating the silica monolit prepared in step 2. The step is to remove the residual organic material by burning and at the same time to strengthen the monolith structure, the powdered silica is heat treated at 400 ~ 800 ℃ 12 to 72 hours. If the heating temperature is less than 400 ℃ may not be sufficient to remove the organic matter, if it exceeds 800 ℃ there is a problem that the silica monolith structure may be modified. In addition, when the heating time is less than 12 hours may not be sufficient to remove the organic matter, even if the treatment for more than 72 hours is not preferable because there is no excellent effect. The step can remove the remaining organic matter by applying a strong heat, it can have an effect that can replace the step of cleaning has the effect of reducing the production cost and the process is simple.

In addition, the present invention provides a silica monolit powder prepared according to the above production method.

The particle size of the silica monolith powder according to the present invention is 1 to 8 µm, and the size of the pupil is 50 to 400 mm 3. Therefore, when this is used as the stationary phase of liquid chromatography, the resolution of the peak is increased and the band broadening effect is reduced.

Furthermore, the present invention provides a stationary phase for liquid chromatography containing the silica monolit powder.

The stationary phase may be prepared by attaching a ligand to the silica monolith powder according to the present invention, and the method of attaching the ligand is not particularly limited. For example, by attaching a ligand using chlorodimethylotadecylsilne or trimethoxytadecylane and further blocking the ends, the remaining silanol groups are inactivated to prepare a stationary phase. have. Alternatively, the stationary phase may be prepared by attaching a polymerization initiator to the silica monolit powder and polymerizing and attaching styrene.

The stationary phase prepared by the above method may be filled in a stainless steel tube coated with glass on the inner wall to prepare a column for liquid chromatography. The filling method is not particularly limited, and may be prepared using, for example, a slurry filling method of applying vibration for 5 minutes at 14,000 psi, 10 minutes at 10,000 psi, and 30 minutes at ps8,000 psi.

Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples are merely to illustrate the invention, but the content of the present invention is not limited by the following examples.

< Example 1> silica Monolit Preparation of Powders 1

Step 1. Silica Monolit Manufacturing steps

4.0 mL TMOS, 880 mg PEG and 900 mg urea were dispersed in 12.0 mL of 0.01N acetic acid aqueous solution and then stirred at 0 ° C. for 40 minutes. Thereafter, the mixed solution was put in a glass container and polymerized at 40 ° C. for 48 hours. The monolith produced after the reaction was heated in an oven at 105 ° C. for 6 hours and then dried in an oven at 120 ° C. for 12 hours to complete the porous pupil structure of the monolith to prepare silica monolith.

Step 2. Silica Prepared in Step 1 Monolit Powder Steps to

The dried monolit was finely powdered using agate mortar and pestle.

Step 3. In step 3 above Powdered Silica Monolit Descent

Silica monolit was prepared by intensive heating at 700 ° C. for 48 hours to remove residual organic matter.

< Example 2> silica Monolit Liquid Chromatography Containing Powder Column Manufacture 1

2.2 mL trimethoxyoctadecylsilane was added to 1 g of the silica monolith powder prepared in Example 1, dispersed in 25 mL of toluene, and reacted at 120 ° C. for 12 hours. After the reaction, it was filtered, washed twice with acetone and dried at 120 ° C. for 2-3 hours. 0.5 mL of trimethylchlorosilane and 0.5 mL of hexamethyldisilazane were added to the dried particles for end-blocking and dispersed in 20.0 mL of toluene, followed by 12 hours at 60 ° C and 110 ° C. After the reaction process for 6 hours at, filtered and then washed in the order of toluene, propanol, acetone to prepare a stationary powder.

The monolithic powder was dispersed in a methanol solution, and the dispersion was subjected to slurry filling in which a stainless steel tube coated with an inner wall was vibrated for 5 minutes at 14,000 psi, 10 minutes at 10,000 psi, and 40 minutes at a pressure of 8,000 psi. A microcolumn was produced.

< Example 3> silica Monolit Of powder Manufacture 2

Step 1. Silica Monolit Manufacturing steps

4.0 mL TMOS, 880 mg PEG and 900 mg urea were dispersed in 12.0 mL of 0.01N acetic acid aqueous solution and then stirred at 0 ° C. for 60 minutes. Thereafter, the mixed solution was put in a glass container and polymerized at 40 ° C. for 48 hours. After the reaction, the monolit was heated in an autoclave at 120 ° C. in a glass container for 18 hours to complete the porous pore structure of the monolit. Since the monolit removed from the autoclave was moisture, it was dried for 10 hours in a 70 ℃ oven to prepare a silica monolit.

Step 2. Silica Prepared in Step 1 Monolit Powder Steps to

The dried monolit was finely powdered using agate mortar and pestle.

Step 3. In step 3 above Powdered Silica Monolit Descent

Silica monolit was prepared by ignition for 48 hours in an electric furnace at 550 ° C. to remove residual organic matter.

< Example 4> silica Monolit Liquid Chromatography Containing Powder Column Manufacture 2

2.0 g of 3-chloropropyltrimethoxysilane was added to 1 g of the silica monolith powder prepared in Example 3, dispersed in 25.0 mL of anhydrous toluene, and reacted at 110 ° C. for 24 hours. After the reaction, the silica monolit powder was filtered using a filter paper, washed with toluene and dried. 0.47 g of sodium diethyldithiocarbamate was dissolved in a solution of 25.0 mL of anhydrous tetrahydrofuran and the dried particles were dispersed and reacted at 55 ° C. under nitrogen flow for 12 hours to attach a polymerization initiator. Silica monolith powder was obtained. After the reaction was terminated, the silica monolit powder attached with the polymerization initiator was filtered off, washed with tetrahydrofuran, 40/60 methanol / water, acetone, and then dried at room temperature in a desiccator.

The silica monolit powder to which the polymerization initiator was attached was dispersed in a solution consisting of 10.0 mL styrene and 25.0 mL toluene, and reacted at 110 ° C. for 48 hours under a nitrogen flow. After completion of the reaction, the silica monolit powder was filtered, washed with toluene under toluene reflux conditions, washed with normal temperature in order of methanol, acetone, and then dried at 60 ° C. for 5 hours to prepare a stationary phase with polystyrene.

The method for filling the stationary phase prepared above was performed in the same manner as in Example 2 to prepare a microcolumn.

< Example 5> silica Monolit Of powder Manufacture 3

Step 1. Silica Monolit Manufacturing steps

5.0 mL TMOS, 1.1 g PEG and 1.2 g urea were dispersed in 17.5 mL of 0.01 N acetic acid aqueous solution and then stirred at 0 ° C. for 60 min. Thereafter, the mixed solution was put in a glass container and polymerized at 40 ° C. for 48 hours. The monoliths in which the polymerization reaction was completed were heated for 6 hours in an oven at 105 ° C. and 12 hours at 120 ° C. to prepare a monolit porous pupil structure.

Silica monolith prepared in step 1 was carried out in the same manner as in steps 2 and 3 of Example 1 except that the step was performed in a 550 ℃ electric furnace in step 3 to prepare a silica monolit powder.

< Example 6> silica Monolit Liquid Chromatography Containing Powder Column Manufacture 3

660 mg of chlorodimethyloctadecylsilane was added to 1 g of the silica monolith powder prepared in Example 5, dispersed in 25.0 mL of toluene, and reacted at 110 ° C. for 24 hours. 0.5 mL of trimethylchlorosilane and 1.5 mL of hexamethyldisilazane were dissolved in 10.0 mL of toluene and slowly added to the particles, followed by reaction at 60 ° C. for 12 hours and 110 ° C. for 12 hours. The terminal blockade process was completed, filtered and then washed in the order of toluene, propanol and acetone to prepare a stationary powder.

< Experimental Example 1> silica Monolit Powder form observation

In order to determine the form of the silica monolith powder prepared in Example 1 was observed using an optical microscope, the results are shown in FIG.

According to Figure 1, it can be seen that composed of small-scale monolit particles having the characteristics of a typical three-dimensional monolit structure with a coarse mobile phase flow passage, the particle size range is about 2-6 ㎛. The average particle size was 2.9 μm.

< Experimental Example 2> silica Monolit Pupil size measurement of powder

In order to measure the pupil size of the silica monolith powder prepared in Example 1, BET / BJH nitrogen adsorption experiment was performed as follows.

In the BET / BJH nitrogen adsorption experiment, the sample was heated at 120 ^o C for 10 hours to remove the adsorbed water, and then measured at 77 ^o K using the BELSORP-Max equipment of BEL-Japan. The obtained BJH differential pore distribution (dV / dlogD) In the diagram, the D value giving the maximum distribution is the average pupil size.

According to the experimental results, it was confirmed that the average pore size inside the silica monolit particles was 100 kPa.

< Experimental Example 3> micro Column Performance check

In order to determine the performance of the microcolumn prepared in Example 2, the following experiment was performed, and the results are shown in FIG. 2.

Using liquid chromatography, a mixed solution of phenol, 2-nitroaniline, acetophenone, benzene, and toluene was sampled, and a solution (containing 0.1% TFA) containing 70/30% by volume of acetonitrile and water was used as a mobile phase. The separation efficiency was measured by moving at a flow rate of 7 μl / min.

Referring to Figure 2, each mixture is to check that a good separation, the number of theoretical plates (N) determined for each solute were calculated by _{^{2 5.54 (t R / W 1}} /2), t R is retention time of the material and, W _1/2 is the peak width of the point where the half-height peak in the chromatogram. As a result, the theoretical number of stages ranging from 28,000 to 40,000 can be obtained, indicating that the column performance is very good.

< Experimental Example 4> silica Monolit Powder form observation

In order to determine the form of the silica monolith powder prepared in Example 3 was observed using an optical microscope, the results are shown in FIG.

According to Figure 3, it can be seen that composed of small-scale monolit particles having the characteristics of a typical three-dimensional monolit structure with a coarse mobile phase flow passage, the particle size range is about 2-8 ㎛. The average particle size was 3.5 μm.

< Experimental Example 5> silica Monolit Pupil size measurement of powder

In order to measure the pupil size of the silica monolith powder prepared in Example 3, BET / BJH nitrogen adsorption experiment was performed as follows.

According to the experimental results, it was confirmed that the average pore size inside the silica monolit particles was 300 kPa.

< Experimental Example 6> silica Monolit Stationary observe

In order to observe the silica monolith stationary phase prepared in Example 4, the silica monolith stationary phase prepared before filling the column was observed using SEM, and the results are shown in FIG. 4.

According to Figure 4, the particle shape is mixed in a variety of dumbbell-shaped, boomerang-shaped, elliptical, circular, snowman, etc., it can be seen that the monolithic flow channel structure can be shown by partially filling the column.

< Experimental Example 7> micro Column Performance check

In order to determine the performance of the microcolumn prepared in Example 4, the following experiment was performed, and the results are shown in FIG. 5.

Using liquid chromatography, a mixed solution of phenol, 2-nitroaniline, acetophenone, benzene, and toluene was used as a sample. The separation efficiency was measured by moving at a flow rate of 7 μl / min.

Referring to Figure 5, each mixture may be confirmed that a well-separated, the number of theoretical plates (N) determined for each solute were calculated by _{^{2 5.54 (t R / W 1}} /2), t R is retention time of the material and, W _1/2 is the peak width of the point where the half-height peak in the chromatogram. As a result, the theoretical number of stages ranging from 22,000 to 26,000 can be obtained, indicating that the performance of the column is good.

< Experimental Example 8> silica Monolit Powder form observation

In order to determine the form of the silica monolit powder prepared in Example 5 was observed using an optical microscope, and the results are shown in FIG.

According to Figure 6, it can be seen that composed of small-scale monolit particles having the characteristics of a typical three-dimensional monolit structure with a coarse mobile phase flow passage, the size range of the particles is about 2-8 ㎛. The average particle size was 3.5 μm.

< Experimental Example 9> silica Monolit Pupil size measurement of powder

In order to measure the pore size of the silica monolith powder prepared in Example 5, BET / BJH nitrogen adsorption experiment was performed as follows.

According to the experimental results, it was confirmed that the average pupil size inside the silica monolit particles was 110 kPa.

< Experimental Example 10> micro Column Performance Check 3

In order to determine the performance of the microcolumn prepared in Example 6, the following experiment was performed, and the results are shown in FIG. 7.

Referring to Figure 7, each mixture may be confirmed that a well-separated, the number of theoretical plates (N) determined for each solute were calculated by _{^{2 5.54 (t R / W 1}} /2), t R is retention time of the material and, W _1/2 is the peak width of the point where the half-height peak in the chromatogram. As a result, the theoretical number of stages ranging from 22,000 to 28,000 can be obtained, indicating that the performance of the column is good.

1: phenol
2: 2-nitroaniline
3: acetophenone
4: benzene
5: toluene

Claims

Preparing a silica monolit (step 1);
Powdering the silica monolith prepared in step 1 (step 2); And
Method for producing a silica monolith powder, comprising the step (step 3) of igniting the silica monolit prepared in step 2 at 400 ~ 800 ℃ 12 to 72 hours.

The method of claim 1, wherein step 1
Mixing 60 to 80% by weight of TAOS, 10 to 40% by weight of water-soluble porogen and 0 to 25% by weight of blowing agent (step a);
Stirring by adding 55-80 wt% of 0.002-0.1 N acid aqueous solution to 20-45 wt% of the mixture mixed in step a (step b);
Heating the mixture to which the acid of step b is added at 40 to 80 ° C. for 12 to 60 hours (step c);
Method for producing a silica monolith powder comprising the step (step d) of heating the product of step c to another temperature in a range of 70 ~ 150 ℃ twice.

The method of claim 2, wherein in step a, TAOS is one selected from the group consisting of tetramethylorthosilicate (TMOS), tetraethylorthosilciate (TEOS) and tetrabutylorthodsilicate (TBOS). A method for producing silica monolit powder.

The method of claim 2, wherein the water-soluble porogen in step a is one selected from the group consisting of polyethylene glycol (polyethleneglycol, PEG), polypropylene glycol (PPG) and polyvinyl alcohol (polyvinylalchohol, PVA) Method for preparing silica monolit powder.

The silica according to claim 2, wherein the blowing agent in step a is one selected from the group consisting of urea, azobisisobutyronitrile (AIBN) and toluenesulfonylhydrazide (TSG). Method for producing monolit powder.

The method of claim 2, wherein the heating in step d is carried out using an autoclave or an oven.

delete

Silica monolith powder prepared according to the method of claim 1.

9. The monolithic silica powder according to claim 8, wherein the silica monolith powder has a particle size of 1 to 8 mu m.

9. The monolithic silica powder according to claim 8, wherein the pore size of the silica monolith powder is 50 to 400 mm 3.

A stationary phase for liquid chromatography comprising the silica monolit powder according to claim 8.