JPH06265534A - Inorganic porous column - Google Patents

Abstract

PURPOSE:To provide an inorganic porous column in which pressure loss is reduced while facilitating handling and the contact area with a sample fluid is increased per unit volume. CONSTITUTION:The inorganic porous column is substantially composed of glass or glass ceramic provided with a three-dimensional meshed continuous through hole having diameter of 500nm or above with pares having diameter in the range of 5-100nm being provided in the inner wall face of the through hole. Total volume of the pores is 10m<3>/t or less which occupies 20-90% of entire volume. The pores occupies 10% or more of the total volume of bubbles.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to an inorganic porous column. The inorganic porous column of the present invention is suitable for chromatography columns such as liquid chromatography and gas chromatography, which carry an enzyme such as glucose isomerase, a catalyst such as platinum and palladium, or a functional group such as octadecyl group. Can be used for. Also,
It can also be used in syringes and blood infusion catheters.

[0002]

2. Description of the Related Art As this type of chromatography column, there are known a column made of an organic polymer such as a styrene / divinylbenzene copolymer and a column packed with an inorganic filler such as silica gel in a cylinder. .

A column made of an organic material has drawbacks such as low pressure resistance due to low strength, swelling / contraction with a solvent, and inability to heat sterilize. Therefore,
Inorganic materials that do not have these difficulties, especially silica gel,
It is commonly used.

[0004]

However, even if the conventional inorganic filler is used, it may be in the form of beads.
It has been found to have drawbacks that are different from organic columns.

That is, a column constituted by filling a cylinder with an inorganic filler such as silica gel has a large resistance to the flow of fluid and hence a large pressure loss. As a result, the flow rate per unit time is reduced, and it takes a long time for analysis to use it as chromatography. Similarly, since the pressure loss is large, when used for instruments such as syringes,
The flow rate of the sample solution becomes extremely slow.

Further, since the flow rate changes depending on the filling state, the analytical value greatly varies between the manufacturing lots of the column.
If you try to use it for blood injection catheter or syringe,
Beads may spill.

Therefore, as a result of research conducted by the present inventors, an inorganic column which is not a packed type but an integrated type and in which the pore diameter and the pore distribution are appropriately controlled has the drawback that the conventional inorganic packed column has. I did not find that.

The present invention was made based on such knowledge. It is an object of the present invention to solve the problems of conventional inorganic columns, and to provide an inorganic porous column that has a small pressure loss and is easy to handle. Another object is to provide an inorganic porous column having a large contact area with the sample fluid per unit volume.

[0009]

The means consists essentially of glass or glass ceramics and has a pore size of 500 nm.
As described above, the through-holes which are continuous in a three-dimensional mesh shape and the pores formed on the inner wall surface of the through-holes have a pore diameter of 5 to 100 nm, and the total volume of the pores is 10 m ³ / t or less, The volume ratio of the through holes to the whole is 20 to 90%, preferably 50 to 80%, and the volume ratio of the pores in all the pores is 10%.
% Or more, preferably 50% or more. Inorganic porous column. In this means, it is desirable that glass or glass-ceramic is silica SiO 2.
_This is the case where ₂ is the main component.

The inorganic porous column of the present invention is obtained by, for example, hydrolyzing and polymerizing a silicon alkoxide in an acidic solution of an organic polymer to gelate a reaction solution, and then to generate an organic polymer in the produced porous gel. It can be produced by removing molecules and then calcining.

If the step of immersing the solidified porous gel in an aqueous ammonia solution is added between the hydrolysis step and the calcination step, the pore diameter and the pore volume ratio can be easily controlled. Further, a mixture of formamide and polyhydric alcohol may be used instead of the organic polymer.

And, the inorganic porous column of the present invention is
Pore diameters of the through holes and the pores formed on the inner wall surface, the total volume of the pores, the volume ratio of the through holes to the entire column, and the volume ratio of the pores to the total volume of the pores and the through holes are important constituent factors. And The three-dimensional structure of the column varies depending on the composition and temperature of the reaction system, the pH value, the molecular weight of the organic polymer, and various conditions that affect the reactivity of the silicon alkoxide. Therefore, although it is difficult to uniformly describe the method of controlling the three-dimensional structure, it is possible to reproducibly provide the target substance having substantially the same pore diameter and the like under the same conditions described above.

The removal of the organic polymer from the porous gel produced as an intermediate substance can be performed to some extent by washing the gel before drying, but it is possible to remove the organic polymer up to a temperature at which the organic polymer decomposes or burns after the washing process. It is more effective to heat the gel for a sufficiently long time to completely remove it.

The organic polymer used in the production of the inorganic porous column of the present invention is theoretically a water-soluble organic polymer which can be formed into an aqueous solution having an appropriate concentration, and is produced by hydrolysis of silicon alkoxide. , As long as it can be uniformly dissolved in a reaction system containing alcohol, specifically, a sodium salt or potassium salt of polystyrenesulfonic acid which is a polymer metal salt, and a polyanion which is a polymer acid and dissociates Polyacrylic acid, which is a high molecular weight base, and polyallylamine and polyethyleneimine, which are high molecular weight bases and generate polycations in aqueous solution, or neutral high molecular weight polyethylene oxide, which has an ether bond in the main chain, and cyclic amide in the side chain. Polyvinylpyrrolidone and the like are preferable.

Glycerin is most suitable as the polyhydric alcohol when a mixture of formamide and a polyhydric alcohol is used instead of the organic polymer. As the silicon alkoxide, tetramethoxysilane, tetraethoxysilane,
Further, there may be mentioned those obtained by appropriately polymerizing these to increase the oxide content.

The inorganic porous column of the present invention exerts the action and effect to be described later if its three-dimensional structure satisfies the above conditions. Therefore, the manufacturing method is not limited.

[0017]

The fluid such as the sample solution enters from one end of the column, passes through the through holes continuous in a three-dimensional mesh, and exits from the other end. During the passage, there is no obstacle such as beads in the conventional packed type column, and moreover, the diameter of the through hole is 500 nm or more, so the resistance received by the fluid is small. Therefore, the pressure loss is also small.

If the through-holes have the same diameter, the higher the volume ratio of the through-holes to the entire column is, the smaller the pressure loss will be. However, if the volume ratio exceeds 90%, the mechanical strength is remarkably impaired. This makes it difficult to construct a column for chromatography etc. by itself. On the other hand, if the volume ratio is less than 20%, the pressure loss is larger than that of the packed column. A suitable volume ratio range for chromatography is 50-80%.

Since the pores are formed on the inner wall of the through hole, the specific surface area is high. Therefore, if functional groups such as octadecyl groups are fixed to the pores by chemical modification, or if enzymes such as glucose isomerase or catalysts such as platinum or palladium are supported, these pores may be formed during the passage of the fluid. Reacts efficiently with molecules. Moreover, since the functional groups are fixed in the pores, the functional groups will not flow even if the fluid flow is fast.

However, the volume ratio of pores in all pores is 1
0% or more is required. This is because if it is less than 10%, the functional groups can hardly be fixed even if the volume ratio of the through holes is increased to 90%. On the other hand, if the total volume of pores exceeds 10 m ³ / t, the mechanical strength will be significantly impaired, and it will be difficult to construct a column for chromatography or the like by itself. The range of the pore volume ratio and the total volume suitable for chromatography is 50% or more with respect to all the pores, and the total volume of the pores is 1 m ³ / t.
Is.

Even if the volume ratio of the through holes and the total volume of the pores with respect to the entire column are higher than the preferable upper limit values described above, as long as they are within the range of the present invention, the outer circumference is covered with a cylinder or the like to mechanically It can be applied to chromatography by reinforcing it.

[0022]

【Example】

-Example 1- First, sodium polystyrene sulfonate (product number 24305-1 manufactured by Aldrich), which is a polymer metal salt, was added to 1
It was dissolved in 5.51 g of a normal nitric acid aqueous solution to give a 20 wt% solution. To this, 5 ml of methanol was added to form a uniform solution, and 5 ml of tetramethoxysilane was added dropwise over about 1 minute to carry out a hydrolysis reaction. After stirring for several minutes, the obtained transparent solution was transferred to a closed container and kept in a constant temperature bath at 40 ° C., whereupon it solidified after about 20 hours.

The solidified sample was aged for several days, and
The solution was immersed in a 1N aqueous ammonia solution at room temperature for 7 days while renewing the solution every day, dried at 60 ° C, and then heated to 500 ° C at a temperature rising rate of 100 ° C / h. Wash the decomposition products of polymeric metal salts with distilled water and
Heat treatment was performed at 0 ° C. for 2 hours. After this, the sample is 150m long
m was machined into a column shape with dimensions of 4.6 mm inner diameter. As a result, a column made of porous silica glass was obtained.

It was confirmed by an electron microscope and mercury intrusion measurement that the through-holes of about 3 μm were present in the column of the obtained porous silica glass in a three-dimensional meshed structure. It was confirmed by nitrogen adsorption measurement that many pores of about 10 nm were present on the inner wall of the through hole. The pore volume and pore diameter of the sample dried at 60 ° C. were almost the same as those of the porous silica glass that had been heat-treated.

Example 2-First, a 25% by weight aqueous solution of polyacrylic acid which is a polymer acid (manufactured by Aldrich, product number 19205-8; molecular weight 9)
10,000) was diluted with distilled water to obtain a 7.4% aqueous solution, and concentrated nitric acid was added to make 1N nitric acid. Polyacrylic acid 0.
To this solution consisting of 4 g and 5.51 g of 1N nitric acid, 7 ml of tetraethoxysilane was added with stirring to carry out a hydrolysis reaction. After a few minutes, the obtained transparent solution was transferred to a closed container and kept in a constant temperature bath at 60 ° C., whereupon it solidified after about 2 hours.

The solidified sample was further aged for several hours, washed several times with distilled water and ethanol, and immersed in a 0.1N aqueous ammonia solution for 7 days at room temperature while renewing the solution every day. It was dried at 60 ° C. Then, it was machined into a column shape having a length of 150 mm and an inner diameter of 4.6 mm.

It was confirmed by an electron microscope and mercury porosimetry that the dried sample had through-holes of about 3 μm arranged in a three-dimensional mesh-like structure. It was confirmed by nitrogen adsorption measurement that many pores of about 10 nm were present on the inner wall of the through hole.

When ethanol was added to the above reaction solution at a maximum of 5 ml and solidified, the through-hole diameter of the obtained porous body became small, and this could be controlled continuously to a minimum of about 0.5 μm. Further, the amount of the 1N nitric acid aqueous solution used was changed from 3.3 g at the minimum to 11 g at the maximum, and the through-pore diameter of the resulting porous body could be controlled in the range of from about 10 μm to the minimum of about 0.2 μm. Further, the through-hole diameter could be similarly controlled by changing the polyacrylic acid concentration or the reaction temperature.

When these dried samples were heated to 800 ° C. at a heating rate of 100 ° C./h and held at this temperature for 2 hours, a column made of porous silica glass having almost the same structure as the dried sample was used. was gotten.

Example 3-First, a 3: 2 molar ratio mixture of formamide and glycerin is prepared. Then, tetramethoxysilane, formamide in glycerin, and a 1N nitric acid (HNO ₃ ) aqueous solution are mixed at a molar ratio of 1: 3: 1.5,
The mixture was stirred and homogenized to obtain a sol-gel reaction solution. 10 ml of this reaction liquid was placed in a cylindrical closed container having a length of 200 mm and an inner diameter of 6 mm, and the container was placed in a thermostatic bath and the temperature of the sol-gel reaction liquid was kept at 60 ° C. for 2 hours to carry out hydrolysis / polycondensation. Was carried out and solidified to obtain a column-shaped sample.

The solidified column-shaped sample was immersed in a 1N aqueous nitric acid solution at room temperature for 1 day, and then in a 0.1N aqueous ammonia solution at room temperature for 7 days while renewing the solution every day, Then, after drying at 60 ° C. for 10 hours, it was heated to 700 ° C. at a heating rate of 100 ° C./hour and heat-treated at 700 ° C. for 2 hours. As a result, a column made of porous silica glass was obtained.

It was confirmed by an electron microscope and mercury porosimetry that the through-holes of about 3 μm were present in the column of the obtained porous silica glass in a three-dimensional meshed structure. It was confirmed by nitrogen adsorption measurement that many pores of about 8 nm were present on the inner wall of the through hole.

-Experimental Example 1-In this experiment, the same raw material as that used for producing the porous column of Example 1 was used, and the amount of tetramethoxysilane dropped was variously changed as shown in Table 1. A porous column was manufactured, and the relationship between the microstructure of the column and its performance was evaluated.

[0034]

[Table 1] The performance evaluation was performed by measuring the pressure loss when the fluid was passed through the column.

That is, first, a porous column was assembled in a liquid chromatography apparatus, a sample solution was flown through the column using a pump that automatically sets the pressure required to obtain a constant flow rate, and the outlet flow rate was 1 ml / min. The inlet pressure required to obtain Since the outlet side is open to the atmosphere, this inlet pressure directly corresponds to the pressure loss. A 9: 1 (volume ratio) mixture of normal hexane and isopropyl alcohol was used as a sample solution.

Then, 10 columns were manufactured under the same manufacturing conditions, the sample solution was flowed, and the maximum value and the minimum value of the pressure loss were recorded. The measurement results are shown in Table 2 together with the column microstructure.

[0037]

[Table 2] As shown in Table 2, column N belonging to the scope of the present invention
o. In Nos. 2 to 4, the pressure loss was small and the variation was small.

On the other hand, the column No. which does not belong to the scope of the present invention. In Nos. 1 and 5, since the volume ratio of the through holes was lower than 20%, the pressure loss was too large to be measured.

-Experimental Example 2- In this experiment, the same raw material as that used for producing the porous column of Example 2 was used, and the tetraethoxysilane dropping amount was variously changed as shown in Table 3. A porous column was manufactured, and the relationship between the microstructure of the column and its performance was evaluated.

[0040]

[Table 3] The performance evaluation was performed by measuring the pressure loss when the fluid was passed through the column in the same manner as in Experimental Example 1. The measurement results are shown in Table 4 together with the column microstructure.

[0041]

[Table 4] As shown in Table 4, column N belonging to the scope of the present invention
o. In Nos. 7 to 9, the pressure loss was small and the variation was small.

On the other hand, the column No. which does not belong to the scope of the present invention. In No. 6, since the volume ratio of the through holes is lower than 20%,
The pressure loss was so large that it could not be measured. Also,
Column No. In No. 10, although the volume ratio of the through hole was barely within the range of the present invention, the diameter of the through hole was too small, and the pressure loss was so large that it could not be measured.

-Experimental Example 3- In this experiment, the same raw material as that used for producing the porous column of Example 3 was used, and the mixing ratio of the raw materials and the reaction temperature were variously changed as shown in Table 5. Then, a porous column was manufactured, and the relationship between the column microstructure and its performance was evaluated.

[0044]

[Table 5] The performance evaluation was performed by measuring the pressure loss when the fluid was passed through the column in the same manner as in Experimental Example 1. The measurement results are shown in Table 6 together with the column microstructure.

[0045]

[Table 6] As shown in Table 6, column N belonging to the scope of the present invention
o. In Nos. 12 to 14, the pressure loss was small and the variation was small.

On the other hand, the column No. which does not belong to the scope of the present invention. In Nos. 11 and 15, although the volume ratio of the through holes was within the range of the present invention, since the through hole diameter was too small, the pressure loss was so large that it could not be measured.

-Comparative Experiment 1-This experiment was conducted using a conventional packed inorganic column for comparison with Experimental Examples 1 to 3.

That is, the diameter is 10 μm and the density is 1.5 g /
cm ³ silica gel beads were packed in a cylinder having a length of 150 mm and an inner diameter of 4.6 mm at a porosity of 40%, and this was assembled as a column in chromatography, and the pressure loss and the flow rate were measured in the same manner as in the above-mentioned experimental examples. went.

As a result, the pressure loss is 70 kg / c at maximum.
m ² was as large as 30 kg / cm ^{2 at} minimum, and there was a considerable difference depending on the column.

-Experimental Example 4 and Comparative Experiment 2-In this experiment, functional groups were actually immobilized on a porous column,
The analysis performance is evaluated. First, a mixed solution of nitrobenzene and toluene was added to an ordinary mobile phase to prepare a sample solution.

Column No. manufactured in Experimental Example 3 After 13 was chemically modified with an octadecyl group, it was mounted on a liquid chromatography device. Then, the sample solution was passed through the liquid chromatography. Then, the octadecyl group was also chemically modified in the column manufactured in Comparative Experiment 1, and then the column was mounted in a liquid chromatography device and the sample solution was flown.

Both columns were able to separate the nitrobenzene peak and the toluene peak in the same manner. The pressure loss when using No. 13 was 1/10 or less of the pressure loss when using the comparative column.

[0053]

INDUSTRIAL APPLICABILITY The inorganic porous column of the present invention has the following great effects. (1) Since it is a column-integrated type, the problem that the flow rate changes depending on the filling state does not occur, and variation between lots is small.

(2) Since the through hole has the hole diameter and the volume ratio appropriately controlled, the pressure loss is small. Therefore, if the inlet pressure is the same, the flow rate per unit time increases, and analysis can be performed in a shorter time than before. Moreover, since all the functional groups fixed to the pores react with the fluid, the consumption efficiency of the functional groups is high. Therefore, it becomes possible to analyze with a short column.

(3) It is easy to handle when used in a blood injection catheter or syringe. (4) Since the shape and size of the fluid flow path are highly uniform,
The distribution between the solution of the analyte and the inner surface of the column does not vary from place to place.

Claims (3)

[Claims] 1. A through hole which is substantially made of glass or glass ceramics and has a hole diameter of 500 nm or more and which is continuous in a three-dimensional mesh, and a hole diameter of 5 to 5 formed on the inner wall surface of the through hole.
With 100 nm pores, the total volume of the pores is 10 m ³ /
The volume ratio of the through holes to the whole is 20 to 90%, and the volume ratio of the pores in all the pores is 10 or less.
% Or more, an inorganic porous column. 2. The inorganic porous column according to claim 1, wherein the glass or glass ceramics contains silica SiO ₂ as a main component. 3. The inorganic porous column according to claim 1 or 2, which is used alone for chromatography.