JP5828453B2 - Method for producing filler - Google Patents

Description

The present invention relates to a process for producing a filler is packed into a column for liquid chromatography, a method of manufacturing a manufacturing method and a liquid chromatography column.

  Conventionally, polymer fillers such as silica gel fillers and styrene-divinylbenzene copolymers have been used as fillers for high performance liquid chromatography.

  However, silica gel fillers have the problem that the usable pH range is narrow, and polymer fillers have the problem that the range of solvents that can be used as the mobile phase is narrow.

Non-Patent Document 1 discloses irregularly shaped polycrystalline porous diamond particles having a particle diameter of 3 to 6 μm, a specific surface area of 153 m ² / g, and a pore diameter of 1.2 to 7.5 nm. Has been. In addition, as a method for producing irregularly shaped polycrystalline porous diamond particles, a method is disclosed in which nanodiamonds are sintered under high pressure of 3 GPa or more and high temperature of 1000 ° C. or more, and then agglomerates are pulverized. ing.

  However, there is a problem that the shape of the polycrystalline porous diamond particles cannot be made spherical.

P. N. Nesterenko, O.D. N. Fedyana, Yu. V. Volgin, Analyst, 2007, 132, 403-405

In view of the problems of the above-described conventional technology, the present invention suppresses the tailing of peaks derived from aromatic compounds with low hydrophobicity and adsorption of aromatic compounds with high hydrophobicity, and is derived from samples with high hydrophobicity. and to provide a filler capable of improving the degree of separation of peaks, a liquid chromatograph having a column and the column the filler is filled.

The method for producing a filler of the present invention is a method for producing a filler packed in a column for liquid chromatography, in which a dispersion in which nanodiamonds are dispersed in an aqueous solution of a water-soluble polymer is spray-dried. Forming a spherical particle containing the nanodiamond and the water-soluble polymer, forming a spherical porous diamond particle by oxidizing and removing the water-soluble polymer contained in the spherical particle, and A process of growing diamond or diamond-like carbon on porous diamond particles using chemical vapor deposition or physical vapor deposition, and oxygen-terminated spherical porous diamond particles on which the diamond or diamond-like carbon is grown In addition, the step of oxidizing and removing graphite, the oxygen termination, and the graphite was oxidized and removed The Jo porous diamond particles having a step of hydrogen termination.

The method for producing a column of the present invention includes a step of producing a filler by the method for producing a filler of the present invention , and a step of filling the column with the filler.

The method for producing a liquid chromatograph of the present invention includes a step of producing a column by the column producing method of the present invention.

According to the present invention, the tailing of peaks derived from aromatic compounds with low hydrophobicity and the occurrence of adsorption of aromatic compounds with high hydrophobicity are suppressed, and the degree of separation of peaks derived from samples with high hydrophobicity is improved. it is possible to provide a liquid chromatograph having a column and the column packing material as possible, the filler is filled.

It is an XPS C1s spectrum of nano diamond. It is IR spectrum of nano diamond and spherical porous diamond particles. It is a SEM photograph of spherical particles containing nanodiamond and polyethylene glycol. 4 is a SEM photograph of spherical porous diamond particles of Reference Example 1. 3 is an XPS C1s spectrum of spherical porous diamond particles of Reference Example 1. 4 is a SEM photograph of spherical porous diamond particles of Reference Example 2. 4 is an XPS C1s spectrum of spherical porous diamond particles of Reference Example 2. 4 is a SEM photograph of spherical porous diamond particles of Reference Example 3. 4 is an XPS C1s spectrum of spherical porous diamond particles of Reference Example 3. 4 is a SEM photograph of spherical porous diamond particles of Example 4. 4 is an XPS C1s spectrum of spherical porous diamond particles of Example 4. 4 is a SEM photograph of spherical porous diamond particles of Example 5. 6 is a chromatogram when the spherical porous diamond particles of Example 4 are used. 6 is a chromatogram when the spherical porous diamond particles of Example 5 are used.

  Next, the form for implementing this invention is demonstrated with drawing.

  The average particle diameter of the spherical porous diamond particles of the present invention is 0.1 μm to 1 mm, preferably 1.5 to 500 μm.

  The average particle diameter of the spherical porous diamond particles is the average value of the diameters or major axes of the 50 spherical porous diamond particles in the field of view of the scanning electron micrograph.

The specific surface area of the spherical porous diamond particles of the present invention is usually ^{10~2000m 2 / g, 50~500m 2 /} g are preferred.

  The specific surface area of the spherical porous diamond particles can be measured using the BET method.

  The total pore volume of the spherical porous diamond particles of the present invention is usually 0.05 to 2 mL / g, preferably 0.5 to 1.5 mL / g.

  The total pore volume of the spherical porous diamond particles can be measured using the BJH method.

  The average pore diameter of the spherical porous diamond particles of the present invention is usually 1 to 500 nm, preferably 5 to 50 nm.

  The average pore diameter of the spherical porous diamond particles can be calculated from the specific surface area and the total pore volume.

The sp ² / sp ³ ratio of the spherical porous diamond particles of the present invention is preferably 0 to 0.3. When the sp ² / sp ³ ratio of the spherical porous diamond particles exceeds 0.3, the hydrophobicity is reduced when analyzed using a liquid chromatograph having a column packed with the spherical porous diamond particles of the present invention. Peak tailing from small aromatic compounds and adsorption of aromatic compounds with large hydrophobicity may occur.

The sp ² / sp ³ ratio of the spherical porous diamond particles can be calculated from the peak area ratio of the sp ² carbon to the sp ³ carbon in the XPS C1s spectrum (S. Kumaragabaran, T. Yamada, S. Shikata, Jpn. J. Appl. Phys., 48, 011602 (2009)).

  The spherical porous diamond particles of the present invention may be oxygen-terminated but are preferably hydrogen-terminated. Thereby, when it analyzes using the liquid chromatograph which has a column with which the spherical porous diamond particle of this invention is packed, the resolution of the peak derived from a sample with large hydrophobicity can be improved.

  The spherical porous diamond particles of the present invention preferably have an alkyl group introduced on the surface. Thereby, when it analyzes using the liquid chromatograph which has a column with which the spherical porous diamond particle of this invention is packed, the resolution of the peak derived from a sample with large hydrophobicity can further be improved.

  Although it does not specifically limit as an alkyl group introduce | transduced on the surface of a spherical porous diamond particle, An octadecyl group, an octyl group, a butyl group, a methyl group etc. are mentioned.

  In the spherical porous diamond particles of the present invention, substituents other than alkyl groups may be introduced on the surface.

  The substituent other than the alkyl group introduced into the surface of the spherical porous diamond particle is not particularly limited, and examples thereof include a phenyl group, an amino group, a cyano group, a sulfo group, a hydroxyl group, a carbonyl group, and a carboxyl group.

  The method for producing spherical porous diamond particles of the present invention includes a step of forming spherical porous diamond particles using nanodiamonds.

  The average particle diameter of nanodiamond is usually 1 to 900 nm, preferably 1 to 100 nm.

  Examples of commercially available products of nanodiamond include NanoAmando (manufactured by Nanocarbon Laboratory) having an average particle diameter of 5 nm, MD-50 (manufactured by Tomei Dia Co., Ltd.) having an average particle diameter of 50 nm, and the like.

  The method of forming spherical porous diamond particles using nano diamond is not particularly limited, but includes rolling granulation method, extrusion granulation method, compression granulation method, melt granulation method, fluidized bed granulation method, crushing Examples thereof include a granulation method, an agitation granulation method, a coating granulation method, a liquid phase granulation method, and a vacuum freeze granulation method. In particular, after spray-drying a dispersion in which nanodiamond is dispersed in an aqueous solution of a water-soluble polymer to form spherical particles containing nanodiamond and the water-soluble polymer, the water-soluble polymer contained in the spherical particles is added. A method of oxidizing and removing is preferable.

  The water-soluble polymer is not particularly limited, and examples thereof include polyethylene glycol, polyvinyl alcohol, polyethylene oxide, polyacrylamide, polyvinyl pyrrolidone, agar, and water-soluble celluloses.

  A method for oxidizing and removing the water-soluble polymer contained in the spherical particles is not particularly limited, and examples thereof include a gas phase oxidation method, a liquid phase oxidation method, and an oxygen plasma treatment.

  In the method for producing spherical porous diamond particles of the present invention, diamond or diamond-like carbon is grown on the spherical porous diamond particles using chemical vapor deposition (CVD) or physical vapor deposition (PVD). It is preferable to further include a step. Thereby, the mechanical strength of the spherical porous diamond particles can be improved.

  The diamond grown on the spherical porous diamond particles may be either single crystal or polycrystal, or may be a mixture of single crystal and polycrystal.

  Although it does not specifically limit as CVD method, Thermal CVD method, Hot filament CVD method, Electron impact CVD method, Thermal plasma CVD method, Low temperature plasma CVD method etc. are mentioned. Moreover, examples of the low temperature plasma CVD method include an RF plasma CVD method, a microwave plasma CVD method, an ECR-plasma CVD method, and a chemical transport method.

  The PVD method is not particularly limited, and examples thereof include an ion beam method, an ion beam sputtering method, and an ionized vapor deposition method.

  The method for producing spherical porous diamond particles according to the present invention preferably further includes a step of oxygen-terminating the spherical porous diamond particles on which diamond or diamond-like carbon is grown and oxidizing and removing graphite. Thereby, when analyzed using a liquid chromatograph having a column packed with the spherical porous diamond particles of the present invention, tailing of peaks derived from aromatic compounds with low hydrophobicity and aromatic compounds with high hydrophobicity Generation | occurrence | production of adsorption | suction can be suppressed.

  A method for oxygen-terminating spherical porous diamond particles on which diamond has grown and oxidizing and removing graphite is not particularly limited, and examples thereof include a gas phase oxidation method, a liquid phase oxidation method, and an oxygen plasma treatment.

  The method for producing spherical porous diamond particles of the present invention preferably further includes a step of hydrogen-termination of the spherical porous diamond particles from which graphite is oxidized and removed while being oxygen-terminated. Thereby, when it analyzes using the liquid chromatograph which has a column with which the spherical porous diamond particle of this invention is packed, the resolution of the peak derived from a sample with large hydrophobicity can be improved.

  A method for hydrogen-termination of spherical porous diamond particles from which oxygen is terminated and graphite is oxidized and removed is not particularly limited, and examples thereof include a hydrogen plasma treatment and a hydrogen annealing method.

  The method for producing spherical porous diamond particles of the present invention preferably further includes a step of introducing a substituent into the surface of the spherical porous diamond particles. Thereby, when it analyzes using the liquid chromatograph which has a column with which the spherical porous diamond particle of this invention is packed, the resolution of the peak derived from a sample with large hydrophobicity can further be improved.

  A method for introducing a substituent into the surface of the spherical porous diamond particle is not particularly limited, but there is a method of irradiating the dispersion liquid in which the hydrogen-terminated spherical porous diamond particle is dispersed in the alkene with ultraviolet rays, etc. Can be mentioned.

  The alkene is not particularly limited as long as it has a double bond at the terminal, and examples thereof include 1-octadecene and 1-octene.

  Instead of hydrogen-termination of spherical porous diamond particles from which oxygen is terminated and graphite is oxidized and removed, a substituent may be introduced on the surface using an aromatic diazonium salt, Grignard reagent, or the like. .

  Further, after reducing the spherical porous diamond particles which have been oxygen-terminated and from which the graphite has been oxidized and removed to introduce hydroxyl groups, substituents may be introduced to the surface using a silane coupling agent.

  Examples of the silane coupling agent include, but are not limited to, monochlorosilane, dichlorosilane, trichlorosilane, monomethoxysilane, dimethoxysilane, trimethoxysilane, monoethoxysilane, diethoxysilane, and triethoxysilane. You may use together.

  The use of the spherical porous diamond particles of the present invention is not particularly limited as long as the porous particles are generally used. However, the filler, the catalyst carrier, the solid acid, and the solid base packed in the liquid chromatograph column are not limited. , Adsorbent, low refractive index material, low dielectric constant material, proton conductor, heat insulating material, gas sensor material and the like. Moreover, you may use the spherical porous diamond particle | grains of this invention as cosmetic powder and an abrasive | polishing agent.

[ Reference Example 1]
After adding 1 g of nanodiamond NanoAmando (manufactured by Nanocarbon Laboratory Co., Ltd.) having an average particle diameter of 5 nm to 20 mL of a 1% by weight aqueous solution of polyethylene glycol having a number average molecular weight of 400, a dispersion was obtained by ultrasonic dispersion. . In addition, the average particle diameter of the nano diamond was measured using a dynamic light scattering measuring apparatus Nicomp 380 (manufactured by Particle Sizing Systems).

FIG. 1 shows the XPS C1s spectrum of nanodiamond. Calculating the ^sp 2 / sp ³ ratio from the peak area ratio of 1, was 0.24. At this time, the binding energies of sp ² carbon and sp ³ carbon are 283.8 eV and 284.8 eV, respectively. The XPS C1s spectrum was measured using an X-ray photoelectron spectrometer (XPS) AXI-Nova SP (manufactured by KRATOS).

FIG. 2A shows the IR spectrum of nanodiamond. FIG. 2A shows that nanodiamond has a peak derived from CH _{2 at} 2879 to 2924 cm ⁻¹ . The IR spectrum was measured by the KBr method using an infrared spectrometer FT / IR-6100 (manufactured by JASCO).

  Using a spray dryer B-290 (manufactured by Büch), the dispersion was spray-dried under the following conditions to obtain spherical particles containing nanodiamond and polyethylene glycol.

Inlet temperature: 180 ° C
Aspirator setting: 100%
Perista pump setting: 20
Rotor meter setting: 30mm
FIG. 3 shows an SEM photograph of spherical particles containing nanodiamond and polyethylene glycol. As a scanning electron microscope (SEM), JSM-6500F (manufactured by JEOL Ltd.) and FE-SEM SUTRA40 (manufactured by Carl Zeiss) were used.

Using a muffle furnace, the mixture was heated at 300 ° C. for 1 hour to oxidize and remove polyethylene glycol contained in the spherical particles to obtain spherical porous diamond particles. The spherical porous diamond particles had a specific surface area of 292 m ² / g, a total pore volume of 0.61 mL / g, and an average pore diameter of 8.4 nm. The specific surface area, total pore volume, and average pore diameter were measured using a high performance / multiple sample / automatic gas adsorption amount measuring device Autosorb-3 (manufactured by Yuasa Ionics).

  FIG. 4 shows an SEM photograph of spherical porous diamond particles. FIG. 4 shows that the spherical porous diamond particles are maintained in a spherical shape. The spherical porous diamond particles had an average particle size of 1.9 μm.

FIG. 5 shows an XPS C1s spectrum of spherical porous diamond particles. The sp ² / sp ³ ratio was calculated from the peak area ratio of FIG.

FIG. 2 (b) shows the IR spectrum of spherical porous diamond particles. FIG. 2 (b) shows that the spherical porous diamond particles do not have a peak derived from CH ₂ but have a minute peak derived from C═O at 1734 cm ⁻¹ .

[ Reference Example 2]
Using a microwave plasma CVD apparatus AX3120 (manufactured by ASTeX), using an acetone / methanol mixed solution (volume ratio 9: 1) as a raw material, diamond is grown on the spherical porous diamond particles of Reference Example 1 under the following conditions. It was. The spherical porous diamond particles had a specific surface area of 295 m ² / g, a total pore volume of 0.60 mL / g, and an average pore diameter of 8.1 nm.

Microwave output: 1300W
Stage temperature: 800 ° C
Hydrogen gas flow rate: 400sccm
Pressure: 50 Torr
Growth time: 10 min
FIG. 6 shows an SEM photograph of spherical porous diamond particles. FIG. 6A shows that the spherical porous diamond particles maintain the spherical shape. The spherical porous diamond particles had an average particle size of 2.0 μm. Furthermore, it can be seen from FIG. 6B that diamond grows on the spherical porous diamond particles and nanodiamonds are bound.

FIG. 7 shows an XPS C1s spectrum of spherical porous diamond particles. When the sp ² / sp ³ ratio was calculated from the peak area ratio in FIG. 7, it was 0.27.

FIG. 2 (c) shows the IR spectrum of spherical porous diamond particles. FIG. 2 (c) shows that the spherical porous diamond particles do not have a peak derived from C═O, but have a minute peak derived from CH _{2 at} 2879 to 2924 cm ⁻¹ .

[ Reference Example 3]
Using a muffle furnace, the mixture was heated at 425 ° C. for 5 hours to terminate the spherical porous diamond particles of Reference Example 2 with oxygen and to remove graphite by oxidation. The spherical porous diamond particles had a specific surface area of 298 m ² / g, a total pore volume of 0.76 mL / g, and an average pore diameter of 10.2 nm.

  FIG. 8 shows an SEM photograph of spherical porous diamond particles. It can be seen from FIG. 8 that the spherical porous diamond particles maintain a spherical shape. The spherical porous diamond particles had an average particle size of 1.9 μm.

FIG. 9 shows an XPS C1s spectrum of spherical porous diamond particles. When the sp ² / sp ³ ratio was calculated from the peak area ratio in FIG. 9, it was 0.06. This shows that the graphite was removed by oxidation.

FIG. 2 (d) shows the IR spectrum of spherical porous diamond particles. FIG. 2D shows that the spherical porous diamond particle does not have a peak derived from CH ₂ but has a peak derived from C═O at 1786 cm ⁻¹ .

[Example 4]
Using a microwave plasma CVD apparatus AX3120 (manufactured by ASTeX), the spherical porous diamond particles of Reference Example 3 were subjected to hydrogen plasma treatment under the following conditions to be hydrogen-terminated. The spherical porous diamond particles had a specific surface area of 333 m ² / g, a total pore volume of 0.78 mL / g, and an average pore diameter of 9.3 nm.

Microwave output: 500W
Stage temperature: 800 ° C
Hydrogen gas flow rate: 100 sccm
Pressure: 25 Torr
Processing time: 1h
FIG. 10 shows an SEM photograph of spherical porous diamond particles. FIG. 10 shows that the spherical porous diamond particles maintain a spherical shape. The spherical porous diamond particles had an average particle size of 2.4 μm.

FIG. 11 shows an XPS C1s spectrum of spherical porous diamond particles. The sp ² / sp ³ ratio calculated from the peak area ratio in FIG. 11 was 0.12. This shows that the graphite was removed by oxidation.

FIG. 2 (e) shows the IR spectrum of spherical porous diamond particles. FIG. 2 (e) shows that the spherical porous diamond particles do not have a C═O-derived peak, but have a CH ₂ -derived peak at 2879 to 2924 cm ⁻¹ .

[Example 5]
While stirring 1 g of the spherical porous diamond particles of Example 4 in 200 mL of 1-octadecene, ultraviolet rays were irradiated under the following conditions using a low pressure mercury lamp SUV40GS-6 (manufactured by Sen Special Light Source Co., Ltd.). Was introduced on the surface. Next, after the spherical porous diamond particles were centrifuged, hexane was added and ultrasonically dispersed. Furthermore, the spherical porous diamond particles were centrifuged and then dried.

Power: 25W
Temperature: Room temperature Wavelength: 254nm
Irradiation time: 7 days FIG. 12 shows an SEM photograph of spherical porous diamond particles. From FIG. 12, it can be seen that the spherical porous diamond particles maintain a spherical shape. The spherical porous diamond particles had an average particle size of 4.9 μm.

FIG. 2 (f) shows an IR spectrum of spherical porous diamond particles. From FIG. 2 (f), it can be seen that the spherical porous diamond particles have peaks derived from CH _{2 at} 2852 cm ⁻¹ and 2922 cm ⁻¹ . This shows that the octadecyl group was introduced into the surface.

Table 1 shows the characteristics of the spherical porous diamond particles of Reference Examples 1 to 3 and Example 4.

[Evaluation of spherical porous diamond particles 1]
The spherical porous diamond particles of Example 4 were packed in a SUS column having an inner diameter of 2 mm and a length of 150 mm. The obtained column was mounted on a high performance liquid chromatograph SI-2 (manufactured by Shiseido Co., Ltd.), and water and acetonitrile were used as mobile phases to elute the sample under the following conditions. As a sample, a solution in which methyl benzoate (2.2 mg / mL), toluene (8.7 mg / mL) and naphthalene (0.9 mg / mL) were dissolved in a 60% by volume acetonitrile aqueous solution was used. The concentration of acetonitrile in the mobile phase was increased from 0% to 100% by volume in 0 to 20 minutes, and then maintained at 100% by volume until 25 minutes.

Flow rate: 100 μL / min
Detector: UV detector (254 nm)
Temperature: 40 ° C
Pressure: 17.1 MPa
Sample injection volume: 5.0 μL
FIG. 13 shows a chromatogram. FIG. 13 shows that the tailing of the peak derived from methyl benzoate and the adsorption of toluene and naphthalene can be suppressed. Moreover, it turns out that the resolution of the peak derived from toluene and the peak derived from naphthalene is excellent.

[Evaluation of spherical porous diamond particles 2]
The spherical porous diamond particles of Example 5 were packed in a SUS column having an inner diameter of 2 mm and a length of 150 mm. The obtained column was mounted on a high performance liquid chromatograph SI-2 (manufactured by Shiseido Co., Ltd.), and a sample was isocratic eluted under the following conditions using a 40 volume% aqueous acetonitrile solution as a mobile phase. As a sample, uracil (0.1 mg / mL), methyl benzoate (2.2 mg / mL), toluene (8.7 mg / mL) and naphthalene (0.9 mg / mL) were dissolved in 60 vol% acetonitrile aqueous solution. The solution was used.

Flow rate: 100 μL / min
Detector: UV detector (254 nm)
Temperature: 40 ° C
Pressure: 8.0 MPa
Sample injection volume: 2.0 μL
FIG. 14 shows a chromatogram. FIG. 14 shows that the tailing of the peak derived from methyl benzoate and the occurrence of adsorption of toluene and naphthalene can be suppressed. Moreover, it turns out that the resolution of the peak derived from toluene and the peak derived from naphthalene is excellent.

Claims (4)

A method for producing a packing material packed in a column for liquid chromatography,
Spray drying a dispersion in which nanodiamond is dispersed in an aqueous solution of a water-soluble polymer to form spherical particles containing the nanodiamond and the water-soluble polymer;
A step of oxidizing and removing the water-soluble polymer contained in the spherical particles to form spherical porous diamond particles;
A step of growing diamond or diamond-like carbon on the spherical porous diamond particles using chemical vapor deposition or physical vapor deposition;
A step of oxygen-terminating the spherical porous diamond particles on which the diamond or diamond-like carbon is grown and oxidizing and removing graphite;
A method for producing a filler, comprising a step of hydrogen-termination of spherical porous diamond particles from which oxygen is terminated and graphite is oxidized and removed.   The method for producing a filler according to claim 1, further comprising a step of introducing an alkyl group into the surface of the hydrogen-terminated spherical porous diamond particles. A step of producing a filler by the method for producing a filler according to claim 1 or 2,
A method for producing a column , comprising a step of filling the column with the filler. Method of manufacturing a liquid chromatograph further comprising a step of producing the column by the method for producing a column of claim 3.