JP3228066B2 - Zirconium oxide for liquid chromatography and its production method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to zirconium oxide for alkali-resistant liquid chromatography and a method for producing the same.
The present invention also relates to a carrier for a separation column suitable for separating biopolymer substances such as peptides and proteins by reversed-phase liquid chromatography.

[0002]

2. Description of the Related Art Silica-based carriers have been often used as column packings in liquid chromatography. However, since silica-based carriers are mainly composed of silicate glass, it is difficult to use them for separation using an alkaline mobile phase, and even if the mobile phase itself is not alkaline, separation using an alkaline washing column after use is required. Basically could not be applied to such. In this regard, the inclusion of a zirconium oxide (ZrO ₂ ) component in the above silicate glass improves alkali resistance as a carrier (Japanese Patent Application Laid-Open Nos. 62-59553 and 62-6).
7450 and 64-46646). Attempts have also been made to use zirconium oxide as a carrier for liquid chromatography for applications requiring alkali resistance (J. Nawrockiet al, J. Chro
matography A, 657, 229-282 (1993)).

[0003]

Although zirconium oxide has the characteristic of being excellent in alkali resistance, it has a problem that the bonding force between primary particles of zirconium oxide is weakened gradually when used for liquid chromatography. there were. An object of the present invention is to solve the above problems and provide a zirconium oxide for chromatography having a strong bonding force between primary particles and a method for producing the same.

[0004]

As a result of studying the above problems, it has been found that, after hydrolyzing an aqueous solution of a zirconium salt, a zirconia sol having a silica content of less than 0.1% by weight in zirconium oxide is calcined. By controlling the firing temperature, it was found that zirconium oxide consisting of a tetragonal system and a monoclinic system having a strong bonding force between primary particles was generated. That is, the present invention is a zirconium oxide for liquid chromatography, comprising 5 to 95% of a tetragonal system and 95 to 5% of a monoclinic system and containing less than 0.1% by weight of silica. Further, in the present invention, a zirconia sol having a silica content of less than 0.1% by weight formed by adding a zirconium salt to an alkaline aqueous solution is heated in an alkaline aqueous solution at 80 ° C. to 150 ° C. for 8 hours or more, and dried. 200
For liquid chromatography, wherein the calcination is carried out at from 5 to 95% of tetragonal system and from 95 to 5% of monoclinic system and the content of silica is less than 0.1% by weight. This is a method for producing zirconium oxide particles.

[0005] The tetragonal system is 5 to 95% and the monoclinic system is 95%.
Within the range of from 5% to 5%, the bonding force of the primary particles inside the particles after the firing treatment is strong. Furthermore, the tetragonal system is 30 to 75
% And zirconium oxide with a monoclinic range of 70 to 25%. In addition, by changing the ratio between the tetragonal system and the monoclinic system, the pore diameter can be greatly changed, so that it can be applied to separation of a wide range of molecular sizes. When zirconium oxide having a silica content of 0.1% by weight or more based on zirconium oxide is prepared, only tetragonal zirconium oxide is obtained. In this case, the bonding force of the primary particles is sufficient. Absent. Sufficient bonding force can be obtained when the ratio of the tetragonal system is 5% or more.
%, The bonding force of the primary particles becomes weak. When preparing the zirconium oxide of the present invention, naturally, the content of silica contained in the zirconium oxide produced also for the raw material other than the zirconium salt is 0.1 to the zirconium oxide.
Care must be taken to make it less than the weight percent. In order to determine the abundance ratio between the tetragonal system and the monoclinic system, powder X-ray diffraction measurement using Kα1 of a Cu target was performed.
The ratio between the peak heights at 30.2 degrees and 2θ = 28.2 degrees was defined as the abundance ratio between the tetragonal system and the monoclinic system.

Hereinafter, a method for producing zirconium oxide will be described in detail. An aqueous solution of a zirconium salt such as zirconium oxychloride, zirconium nitrate, or zirconium sulfate in an aqueous alkali solution such as sodium hydroxide, potassium hydroxide, or ammonia (concentration of 0.1 as ZrO ₂₎ .
5 to 2 mol / L), and after complete hydrolysis,
This aqueous solution is subjected to a heat treatment under reflux or pressure at 80 to 150 ° C. under alkaline conditions. In the heat treatment process, a zirconia aqueous solution is solified or shows a significant thickening phenomenon from weakly acidic to neutral, so it is necessary to add a zirconium salt aqueous solution to an excess alkali. If the heat treatment time is short, the cohesion of the primary particles is weakened because the colloid formation is incomplete. Therefore, unless heat treatment is performed for at least 8 hours, it is not suitable as a filler for liquid chromatography. The reflux or pressurization time affects various physical properties of zirconium oxide, and is preferably 8 to 500 hours. More preferably, 1
0 to 500 hours is desirable. By washing and spray-drying the obtained zirconium oxide colloid solution, spherical zirconium oxide particles can be obtained. The spherical zirconium oxide particles after spray drying are calcined at 200 to 800 ° C. to obtain a liquid chromatography carrier. After washing the washed zirconium oxide colloid, it can be calcined at 200 to 800 ° C., and then the sintered body can be mechanically pulverized to obtain a crushed liquid chromatography carrier. For chromatography, the particle diameter is preferably 0.5 μm to 300 μm, whether spherical or crushed. If the particle diameter is smaller than 0.5 μm, the pressure loss in the column is too large or the filter is clogged.
If the particle diameter is larger than 300 μm, the separation becomes worse. More preferably, it is particularly preferably from 3 μm to 100 μm.

The control of the average particle diameter and pore diameter of the zirconium oxide particles and the ratio between the tetragonal system and the monoclinic system are performed by the following method. [Control of Average Particle Diameter] To obtain spherical particles, a spray drying operation is used. The washed zirconia is re-slurried, and the slurry concentration at this time affects spheroidization or average particle diameter by spray drying. Generally, the lower the slurry concentration, the smaller the particle diameter.
When the amount is less than 25% by weight, the amount of irregular fine particles increases and the weight becomes 25% by weight.
Above this, the viscosity increases and the treatment becomes difficult.
To 25% by weight of the slurry is used. More preferably, a slurry concentration of 8 to 18% by weight is desirable. When using an atomizer type spray dryer in spray drying, spherical zirconium oxide particles with a small average particle diameter can be obtained by increasing the number of revolutions of the atomizer or spraying from a nozzle, which also controls the particle diameter. can do.

[Control of Pore Diameter and Ratio of Tetragonal System and Monoclinic System] The baking treatment after spray drying affects the pore diameter of zirconium oxide. The pore diameter increases significantly as the firing temperature increases. At the same time, the proportion of the portion having a tetragonal structure is reduced and the proportion of the monoclinic is increased. That is, by controlling the temperature of the firing treatment, the pore diameter and the ratio of the tetragonal system to the monoclinic system can be determined. Since the mechanical strength of the particles suddenly weakens at 900 ° C. or higher, the firing temperature is desirably up to 800 ° C. When the mechanical strength of the particles is particularly required, firing at 200 to 600 ° C. is more preferable.

The obtained tetragonal and monoclinic zirconium oxide particles having a diameter of 20 μm are converted into an inner diameter of 6 mmφ.
A column having a length of 150 mm was packed, and an alkali resistance durability test was performed using 1N-NaOH as a mobile phase. 1N-
When NaOH was passed at a flow rate of 1 ml / min, no outflow of Zr was observed even after 5000 hours had passed, indicating that zirconium oxide for liquid chromatography having sufficient alkali resistance was obtained.

[0010] The surface of the zirconium oxide particles thus obtained is coated with octadecyldimethylchlorosilane, ethylchlorosilane, aminopropyltrimethoxysilane,
Silanes such as cyanopropyldimethylchlorosilane; zirconiums such as octadecyldimethylchlorozirconium and cyclopentadecyl-trichloro-zirconium; aluminums such as dimethylaluminum chloride and diisobutylaluminum chloride; or diethyl-dichloro-titanium and ethyl-trichloro-
Modification using a titanium-based coupling agent such as titanium, or at least one compound selected from the group consisting of alcohols such as n-octyl alcohol and stearyl alcohol or halogenated hydrocarbons such as n-octyl chloride and stearyl chloride. Then, it can be used as a carrier for reversed-phase liquid chromatography. For example, when octadecyldimethylchlorosilane (ODS) is modified, it can be applied to efficient separation and analysis of biopolymers such as peptides and proteins by using a buffer having a pH of 2 to 12 as a mobile phase.

[0011]

【Example】

Example 1 1 mol / L in 4 L of 4 mol / L sodium hydroxide
4 L of an aqueous solution of zirconium oxychloride was dropped and mixed at 4 L / h to produce a zirconia sol. The content of silicon in the zirconium oxychloride used here was 0.05% by weight of silica based on zirconium oxide. The obtained zirconia sol was placed in a 10 L autoclave at 105 ° C. for 5 hours.
Hydrothermal treatment was performed for 6 hours. This was washed by centrifugation and slurried again to make the slurry concentration 13%. Using an atomizer type spray dryer, the flow rate was 1 L /
h, hot air temperature 150 ° C, disk rotation speed 15000rpm
m, a spherical zirconium oxide having an average particle diameter of 34 μm was obtained. When this was fired at 600 ° C. for 2 hours, zirconium oxide composed of tetragonal and monoclinic crystals having a pore diameter of 167 Å, a pore volume of 0.15 ml / g, and a surface area of 57 m ² / g was obtained. This is 1N
Acid treatment was carried out by stirring in -HCl for 1 hour to obtain zirconium oxide particles for normal phase liquid chromatography. The distribution of the pore diameter was measured using a mercury intrusion pore distribution measuring apparatus, and the pore diameter having the largest distribution was defined as the pore diameter of the particles. X-ray diffraction measurement of the obtained zirconium oxide showed that the ratio between the tetragonal peak height and the monoclinic peak height was 31/69. The content of silica in zirconium oxide was determined by X-ray fluorescence measurement.

Pulverization test 0.4 g of zirconium oxide particles having a particle diameter of 20 μm obtained by classification are placed in a glass beaker, and 9.6 g of water are added to make a total weight of 10 g. Let stand for minutes. Thereafter, the supernatant was removed, water was added again, the total weight of water and the sample was adjusted to 10 g, and the same ultrasonic treatment as described above was further repeated twice. Immediately after the third sonication operation, the intensity of the binding force of the primary particles was measured by measuring the absorbance of visible light of the supernatant. The higher the absorbance, the more the melting is progressing, and the lower the binding power of the primary particles. The tendency of the peptizing test does not change even when the particle diameter changes, and this method is an appropriate method for knowing the binding force of the primary particles.

Examples 2, 3, and 4 Zirconium oxide particles were prepared in the same manner as in Example 1 except that the sintering temperature was changed from 600 ° C. to 200, 400 and 800 ° C., and the obtained zirconium oxide particles were subjected to X-ray diffraction. Measurements, analysis of silica content and peptization tests were performed. These are referred to as Examples 2, 3, and 4, respectively.

Comparative Example 1 Example 1 except that the sintering temperature was changed from 600 ° C. to 1000 ° C.
Zirconium oxide particles were produced in the same manner as described above, and were subjected to X-ray diffraction measurement and peptization test. Although the pore diameter becomes as large as 2200 angstroms, the bonding force of the primary particles is weak according to the peptization test.

COMPARATIVE EXAMPLE 2 When producing a zirconia sol, 4.3 g of an aqueous solution of sodium silicate No. 3 (corresponding to 1% by weight of silica based on zirconium oxide) was added to an aqueous solution of sodium hydroxide, and then zirconium oxychloride was added. Zirconium oxide particles were produced in the same manner as in Example 3 except that the aqueous solution was dropped and mixed. In this case, when the obtained zirconium oxide particles were subjected to X-ray diffraction measurement, only peaks corresponding to tetragonal crystals were observed. The peptizing test was performed in the same manner as in Example 1. Table 1 summarizes the results of the above examples and comparative examples.

[0016]

[Table 1]

Example 5 20 g of zirconium oxide particles having a pore diameter of 1436 Å, a pore volume of 0.25 ml / g and a surface area of 26 m ² / g obtained in Example 4 were stirred at 105 ° C. for 2 hours in 160 ml of toluene. Then, the water molecules adsorbed on the zirconium oxide were dehydrated at normal pressure. Then 2g OD
S and 0.46 g of pyridine were added, and the mixture was refluxed at 105 ° C. for 3 hours. Thereafter, 0.5 g of trimethylchlorosilane (TMCS) and 0.1 g of hexamethyldisilazane (HMDS) were added.
5 g and 0.3 g of pyridine were added, and an end capping treatment was performed at 105 ° C. for 3 hours. Thereafter, methanol was quickly added, and the mixture was thoroughly washed with n-hexane and methanol to remove residual ODS, TMCS, and HMDS. After this 80
The dried zirconium oxide particles for reversed-phase liquid chromatography were obtained by drying at ℃.

Example 6 The reversed phase zirconium oxide particles obtained in Example 5 were packed in a column having an inner diameter of 4 mmφ and a length of 15 cm, and the separation state of liquid chromatography was examined. Separation was attempted with water / methanol = 30/70 as the mobile phase. The supply rate of the mobile phase was 0.45 ml / min, the column temperature was 40 ° C., uracil, methyl benzoate, toluene and naphthalene were used as samples, and detection was performed at UV 254 nm. Next, after the liquid was continuously passed for 2000 hours, the same measurement was performed, but no change was observed in the retention time. As an alkali resistance test, dil. NaOH / methanol = 30/7
When the separation state was examined under the same conditions as above using a mobile phase of 0, there was no change in the retention time after passing the solution continuously for 1000 hours.

Example 7 The pore diameter of 167 Å obtained in Example 1 was obtained.
Zirconium oxide particles for reversed-phase liquid chromatography, the surface of which was ODS-modified, were prepared in the same manner as in Example 5, except that zirconium oxide having a pore volume of 0.15 ml / g and a surface area of 57 m ² / g was used. In order to conduct an alkali resistance test of the zirconium oxide particles, the separation state of liquid chromatography was examined in the same manner as in Example 6, but no change was observed in the retention time.

[0020]

When the content of silica is less than 0.1% by weight with respect to zirconium oxide, tetragonal and monoclinic zirconium oxide can be obtained. Especially 200-8
Zirconium oxide having a tetragonal system content of 5 to 95% and a monoclinic system content of 95 to 5% obtained by calcining at 00 ° C. has a strong binding force of primary particles, so that it is used as alkali-resistant particles for liquid chromatography. It is suitable. If the zirconium oxide particles are modified with a silane-based, aluminum-based, titanium-based, or zirconium-based coupling agent or an alcohol or a halogenated hydrocarbon, reversed-phase zirconium oxide particles can be obtained.

Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C01G 25/00 G01N 30/48 CA (STN)

Claims (9)

(57) [Claims] 1. Zirconium oxide for liquid chromatography comprising from 5 to 95% tetragonal and from 95 to 5% monoclinic having a silica content of less than 0.1% by weight. 2. The porous zirconium oxide particles for liquid chromatography according to claim 1, having an average particle diameter of 0.5 to 300 microns and a pore diameter of 100 to 1500 angstroms. 3. A silane-based, aluminum-based, titanium-based,
3. The zirconium oxide particles for liquid chromatography according to claim 2, wherein said zirconium oxide particles are modified with a zirconium-based coupling agent or an alcohol or a halogenated hydrocarbon. 4. The zirconium oxide particles for liquid chromatography according to claim 3, wherein the silane coupling agent is octadecyldimethylchlorosilane. 5. A zirconia sol having a silica content of less than 0.1% by weight, which is formed by adding a zirconium salt to an alkaline aqueous solution, is treated in an alkaline aqueous solution with a zirconia sol of 80 to 150%.
After heating at ℃ for more than 8 hours, it was dried.
Zirconium oxide particles for liquid chromatography, wherein the zirconium oxide particles comprise 5 to 95% of a tetragonal system and 95 to 5% of a monoclinic system and have a silica content of less than 0.1% by weight, which is calcined at 00 ° C. How to manufacture. 6. The method for producing zirconium oxide particles for liquid chromatography according to claim 5, wherein the zirconium salt is a water-soluble zirconium salt selected from the group consisting of zirconium oxychloride, zirconium nitrate and zirconium sulfate. . 7. The method for producing zirconium oxide particles for liquid chromatography according to claim 5, wherein the drying is spray drying. 8. The method for producing zirconium oxide particles for liquid chromatography according to claim 5, wherein the bulk zirconium oxide is crushed after the calcination treatment. 9. Zirconium oxide particles having an average particle diameter of 0.5 to 300 microns and a pore diameter of 100 to 1
9. The method for producing zirconium oxide particles for liquid chromatography according to claim 6, wherein the particle diameter is 500 angstroms.