Preparation method and application of nano-material capillary electrochromatographic column synthesized based on CMOFs and CMIPs

Abstract

The invention discloses a preparation method and application of a nano-material capillary electrochromatographic column synthesized based on CMOFs and CMIPs. Co (ClO4) 2.6 H2O, L-tryptophan, isonicotinic acid and water are used as raw materials to synthesize a chiral metal organic framework (CMOFs) nano material; adding the obtained CMOFs into deionized water, carrying out ultrasonic treatment to obtain dispersion liquid of the CMOFs, dissolving L-amlodipine, APTES and the like in ethanol / water, adding the dispersion liquid, TEOS and ammonia water, and flushing into an activated capillary tube to obtain the capillary electrochromatographic column. CMOFs and chiral molecularly imprinted polymers (CMIPs) are adopted as raw materials to synthesize a CMIPs-CMOFs nano material, the CMIPs-CMOFs nano material serves as a stationary phase to prepare the capillary electrochromatography coating column, the capillary electrochromatography column prepared through the method is good in chromatographic performance, and efficient and high-separation-degree separation analysis of chiral amlodipine enantiomers is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical synthesis and analysis, and relates to a preparation method and application of a novel nanomaterial capillary electrochromatographic column synthesized based on CMOFs and CMIPs, specifically to a novel nanomaterial capillary electrochromatographic column synthesized based on chiral metal organic frameworks and chiral molecular imprinted polymers, a preparation method and application in the separation of the chiral drug amlodipine. Background Art

[0002] Chirality is widely present in nature. Most of the biomacromolecules that constitute the life system exist only as a single enantiomer. Generally speaking, for chiral drugs, each single enantiomer may exhibit very different pharmacological and toxicological properties. Therefore, the separation and purification of single enantiomers has very important theoretical and practical significance.

[0003] At present, the single enantiomer separation methods of chiral drugs mainly include high performance liquid chromatography (HPLC), gas chromatography (GC), capillary electrophoresis / electrochromatography (CE / CEC), etc. Among them, CEC technology combines the advantages of CE and HPLC. CEC overcomes the peak broadening caused by pressure-driven liquid chromatography, while retaining the high selectivity of HPLC and the high efficiency of CE. It has the advantages of fast speed, high column efficiency, and small sample usage. CEC capillary columns can be divided into packed columns, monolithic columns, and coated columns. Among them, coated columns are widely used due to their simple preparation, high column efficiency, and easy modification. However, coated columns also have disadvantages such as small column capacity and weak chiral separation ability. In order to overcome this problem, it has been reported that nanomaterials such as metal organic frameworks (MOFs) are modified to the inner wall of the capillary to increase its specific surface area.

[0004] Chiral metal organic frameworks (CMOFs) are a new type of microporous crystalline nanomaterials, which are highly ordered organic-inorganic hybrid composite materials composed of organic linkers and metal ions. By selecting appropriate metal ions and organic ligands, CMOFs with specific pore sizes, specific spatial structures, and specific functional groups can be obtained. Due to the rich variety of selectable metal ions and organic ligands, the prepared CMOFs generally have the characteristics of large specific surface area, excellent thermal and chemical stability, and easy surface structure modification, so they are widely used in sensing, catalysis, separation analysis and other fields.

[0005] Chiral molecular imprinted polymers (CMIPs) use a single enantiomer of a chiral drug as a template molecule. The template molecule is used to undergo a copolymerization condensation reaction with a functional monomer and a cross-linking agent to synthesize a specific recognition cavity. The shape and size of the formed cavity are complementary to the template molecule. CMIPs can selectively recognize and capture organic polymers that have specific recognition capabilities for specific template molecules, thereby facilitating the effective separation of samples. Due to the advantages of low cost, easy preparation, and strong chemical stability, CMIPs have attracted much attention in the field of chiral separation.

[0006] In previous studies, both CMIPs and CMOFs have the ability to separate single enantiomers, but their single enantiomer separation performance does not achieve the desired effect. Therefore, the present invention uses CMOFs (Co2 (L-Trp) (INT) 2 (H2O) 2 (ClO4)) and a new nanomaterial synthesized by CMIPs as a stationary phase to prepare a new capillary coating column for separating chiral amlodipine. The literature report of this CEC column has not been found internationally. Summary of the invention

[0007] In view of the problems existing in the above-mentioned prior art, the present invention provides a preparation method of a nanomaterial capillary electrochromatographic column synthesized based on CMOFs and CMIPs and an application thereof. Chiral metal organic framework materials and chiral molecular imprinting polymers are used as raw materials to synthesize CMIPs@CMOFs nanomaterials, and a capillary electrochromatographic coating column is prepared using the CMIPs@CMOFs nanomaterials as stationary phases. The prepared capillary column has good chromatographic performance and realizes efficient and high-resolution separation and analysis of chiral amlodipine enantiomers.

[0008] The present invention achieves the above-mentioned purpose by adopting the following technical solutions:

[0009] In a first aspect, the present invention provides a method for preparing a nanomaterial capillary electrochromatographic column synthesized based on CMOFs and CMIPs, comprising the following steps:

[0010] (1) Rinse the quartz capillary and blow dry to obtain a pretreated capillary;

[0011] (2) Co(ClO4)2·6H2O, L-tryptophan, isonicotinic acid, water and ethanol were mixed and added into a reactor, the reactor was sealed, heated at 120°C for 5 days, and after cooling, the crystals were collected, washed and dried to obtain Co2(L-Trp)(INT)2(H2O)2(ClO4), wherein the molar ratio of Co(ClO4)2·6H2O, L-tryptophan and isonicotinic acid was 1:1:1;

[0012] (3) 0.6 mg Co2(L-Trp)(INT)2(H2O)2(ClO4) was added to 1 mL deionized water and ultrasonicated for 5 min to make it uniformly dispersed. 0.5 mg levoamlodipine monomer and 10 μL APTES (3-aminopropyltriethoxysilane) were added to 7.5 mL of ethanol / water mixture and magnetically stirred for 30 min. After stirring, 0.5 mL Co2(L-Trp)(INT)2(H2O)2(ClO4) dispersion, 10 μL TEOS (tetraethoxysilane) and 10 μL NH3·H2O were added to the above solution and shaken for 3 min to obtain L-AM@CMIP(APTES-TEOS)@Co2(L-Trp)(INT)2(H2O)2(ClO4);

[0013] (4) Inject the sample obtained in step (3) into the capillary pretreated in step (1), seal both ends and incubate at room temperature, and after the incubation is completed, rinse with a rinse solution to remove the template molecule to obtain L-AM@CMIP(APTES-TEOS)@Co2(L-Trp)(INT)2(H2O)2(ClO4)@capillary. Preferably, the capillary column is an empty quartz capillary with an inner diameter of 75 microns and a total length of 40 cm.

[0014] Preferably, in step (1), the steps of pretreating the capillary are as follows: first rinse the capillary with NaOH for 1 hour, rinse the capillary with H2O for 5 minutes, rinse the capillary with HCl for 30 minutes, then rinse with deionized water until neutral, rinse with methanol for 30 minutes and then blow dry with N2. After the treatment, the capillary column is placed in a forced air drying oven and dried at 100°C for 1 hour.

[0015] Preferably, the concentration of NaOH solution and HCL solution is 1 mol.L -1 .

[0016] Preferably, in step (3), the volume ratio of ethanol to water in the ethanol / water mixture is 2:1.

[0017] Preferably, in step (4), the incubation time is 16 hours.

[0018] Preferably, in step (4), the flushing liquid is a mixture of methanol / acetic acid in a volume ratio of 9:1, and the flushing time is 2 hours.

[0019] In a second aspect, the present invention provides use of the capillary electrochromatographic column in the separation of amlodipine by capillary electrochromatography.

[0020] In the application, the sample injection process is: adding amlodipine to a mixed solution of water and methanol to prepare a solution with a concentration of 0.5 mg / mL, and filtering through a 0.45 μm organic filter membrane, wherein the volume ratio of water to methanol is 1:1.

[0021] In the application, the conditions for separating amlodipine by capillary electrochromatography are: 10mM NaH2PO4 / Na2HPO4 buffer, separation voltage 20KV, room temperature, injection pressure 40-60mbar, injection time 2-4s, detection wavelength 225nm, running time 10min, wherein the pH of the buffer solution is 7.6 or 7.8.

[0022] The present invention has the following beneficial effects:

[0023] (1) The L-AM@CMIP(APTES-TEOS)@Co2(L-Trp)(INT)2(H2O)2(ClO4)@capillary prepared by the present invention has excellent performance and low cost.

[0024] (2) The L-AM@CMIP(APTES-TEOS)@Co2(L-Trp)(INT)2(H2O)2(ClO4)@capillary prepared by the present invention has a good separation effect for amlodipine.

[0025] (3) The new nanomaterials synthesized by CMOFs and CMIPs were used as stationary phases to separate chiral amlodipine in capillary coated columns. The high specific surface area of ​​CMOFs can increase the loading capacity of molecular imprinting, and the rigid skeleton of CMOFs can play a supporting role, reducing the deformation and collapse of CMIPs pores. The viscosity of CMIPs can increase the stability of the connection between the stationary phase and the inner wall of the capillary. CMOFs and CMIPs have a synergistic effect, greatly improving the chiral selectivity of the new nanomaterials. The combination of the two can maximize the benefits of improving the performance of the stationary phase.

[0026] (4) Compared with the capillary coated columns with CMOFs and CMIPs as the stationary phase alone, the chiral recognition performance of the novel capillary coated column prepared by the present invention is greatly improved, with a separation degree of 0 / 0→5.08, achieving an effect of 1+1>2. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the preparation process of L-AM@CMIP(APTES-TEOS)@Co2(L-Trp)(INT)2(H2O)2(ClO4)@capillary;

[0028] Figure 2This is a transmission electron microscopy image of Co2(L-Trp)(INT)2(H2O)2(ClO4) prepared in Example 1;

[0029] Figure 3 This is the transmission electron microscopy image of L-AM@CMIP(APTES-TEOS)@Co2(L-Trp)(INT)2(H2O)2(ClO4) prepared in Example 1;

[0030] Figure 4 Scanning electron microscope images of an empty capillary column, L-AM@CMIP(APTES-TEOS)@Co2(L-Trp)(INT)2(H2O)2(ClO4)@capillary prepared in Example 1, Co2(L-Trp)(INT)2(H2O)2(ClO4) prepared in Example 1, and L-AM@CMIP(APTES-TEOS)@Co2(L-Trp)(INT)2(H2O)2(ClO4) prepared in Example 1 ( Figure 4 a is the scanning electron microscope image of the empty capillary column; Figure 4 b is the scanning electron microscopy image of L-AM@CMIP(APTES-TEOS)@Co2(L-Trp)(INT)2(H2O)2(ClO4)@capillary; Figure 4 c is the scanning electron microscope image of Co2(L-Trp)(INT)2(H2O)2(ClO4) (resolution: 5μm); Figure 4 d is the scanning electron microscope image of L-AM@CMIP(APTES-TEOS)@Co2(L-Trp)(INT)2(H2O)2(ClO4) (resolution: 5μm); Figure 4 e is the scanning electron microscope image of Co2(L-Trp)(INT)2(H2O)2(ClO4) (resolution: 1 μm); Figure 4 f is the scanning electron microscope image of L-AM@CMIP(APTES-TEOS)@Co2(L-Trp)(INT)2(H2O)2(ClO4) (resolution: 1 μm); Figure 4 g is the energy dispersive X-ray spectrum of Co2(L-Trp)(INT)2(H2O)2(ClO4); Figure 4 h is the energy dispersive X-ray spectrum of L-AM@CMIP(APTES-TEOS)@Co2(L-Trp)(INT)2(H2O)2(ClO4);

[0031] Figure 5 The X-ray photoelectron spectrum of Co2(L-Trp)(INT)2(H2O)2(ClO4) prepared in Example 1;

[0032] Figure 6 The CEC chiral separation result of racemic amlodipine by L-AM@CMIP(APTES-TEOS)@Co2(L-Trp)(INT)2(H2O)2(ClO4)@capillary prepared in Example 1;

[0033] Figure 7 This is a comparison of the chiral separation performance of racemic amlodipine by capillary coated columns with Comparative Example 1 Co2(L-Trp)(INT)2(H2O)2ClO4 and Comparative Example 2 L-AM@CMIP(APTES-TEOS) alone as the stationary phase, and Example 1 L-AM@CMIP(APTES-TEOS)@Co2(L-Trp)(INT)2(H2O)2(ClO4)@capillary. Blue line: capillary coated column with CMIPs alone as the stationary phase; purple line: capillary coated column with Co2(L-Trp)(INT)2(H2O)2(ClO4) alone as the stationary phase; black line: L-AM@CMIP(APTES-TEOS)@Co2(L-Trp)(INT)2(H2O)2(ClO4)@capillary. DETAILED DESCRIPTION

[0034] For a better understanding of the present invention, the following examples are provided to further illustrate the present invention, but the present invention is not limited to the following examples.

[0035] Embodiment 1:

[0036] A method for preparing a nanomaterial capillary electrochromatographic column synthesized based on CMOFs and CMIPs, specifically comprising the following steps:

[0037] First, rinse the capillary with 1M NaOH for 1 hour, 1M H2O for 5 minutes, and 1M HCl for 30 minutes. Then rinse with deionized water until neutral, rinse with methanol for 30 minutes, and blow dry with N2. After the treatment, place the capillary column in a forced air drying oven at 100°C for 1 hour. After the drying time is over, take it out for use.

[0038] A mixture of Co(ClO4)2·6H2O (6.6mmol, 2.420g), L-tryptophan (6.6mmol, 1.320g), isonicotinic acid (6.6mmol, 0.792g), ethanol (22mL) and water (2.2mL) was transferred into a 50mL reactor. Then, the reactor was sealed and heated at 120°C for 5 days. After cooling, the red block crystals were collected and washed with ethanol. Finally, the crystals were dried under ambient conditions to obtain Co2(L-Trp)(INT)2(H2O)2(ClO4).

[0039] 0.6 mg Co2(L-Trp)(INT)2(H2O)2(ClO4) was added to 1 mL deionized water and ultrasonicated for 5 min to make it uniformly dispersed. 0.5 mg levamlodipine monomer and 10 μL APTES were dissolved in 7.5 mL ethanol / water (2:1, V / V) and magnetically stirred for 30 min. After stirring, 0.5 mL Co2(L-Trp)(INT)2(H2O)2(ClO4) dispersion, 10 μL TEOS and 10 μL NH3·H2O were added to the above solution and shaken for 3 min to obtain L-AM@CMIP(APTES-TEOS)@Co2(L-Trp)(INT)2(H2O)2(ClO4).

[0040] The obtained sample was injected into the capillary activated in step (1), and the two ends were sealed and incubated at room temperature for 16 hours. After the reaction was completed, it was rinsed with a rinse solution (methanol / acetic acid, 9:1, V / V) for 2 hours to remove the template molecule, and a capillary electrochromatographic column L-AM@CMIP(APTES-TEOS)@Co2(L-Trp)(INT)2(H2O)2(ClO4)@capillary was prepared. Figure 1 shown.

[0041] Figure 3 and Figure 2 In comparison, it is clearly visible that the transmission electron microscopy image changes from a common flake structure to a porous flake structure; this preliminarily indicates the successful preparation of L-AM@CMIP(APTES-TEOS)@Co2(L-Trp)(INT)2(H2O)2(ClO4);

[0042] Figure 4 b and Figure 4 Compared with the empty capillary column of a, it is obvious that Figure 4 The new CMIPs@CMOFs nanomaterial synthesized in b was successfully attached to the inner wall of the capillary; Figure 4 f Figure 4 e compared, it is obvious that the electron microscope image changes from a polyhedron to a sphere; Figure 4 h and Figure 4 Compared with g, it is obvious Figure 4 The CMOFs in g do not contain Si. Figure 4In the energy dispersive X-ray spectrum of the new CMIPs@CMOFs nanomaterial synthesized in h, obvious peaks corresponding to the Si element appeared; the above comparison figures can further demonstrate the successful synthesis of Co2(L-Trp)(INT)2(H2O)2(ClO4) and L-AM@CMIP(APTES-TEOS)@Co2(L-Trp)(INT)2(H2O)2(ClO4) stationary phases and the successful preparation of L-AM@CMIP(APTES-TEOS)@Co2(L-Trp)(INT)2(H2O)2(ClO4)@capillary.

[0043] Figure 5 As shown, the energy spectrum peaks and chemical bonds corresponding to the metal ion Co, as well as C, N, and O in Co2(L-Trp)(INT)2(H2O)2(ClO4) were effectively identified in the X-ray photoelectron energy spectrum. The results further demonstrated the successful preparation of Co2(L-Trp)(INT)2(H2O)2(ClO4).

[0044] Application of Capillary Electrochromatography for Separation of Amlodipine:

[0045] Amlodipine (racemic) was dissolved in a mixed solution of water and methanol (1:1, V / V) with a concentration of 0.5 mg / mL. All solutions (including test samples) were filtered through a 0.45 μm organic filter membrane. The experiment used an empty quartz capillary column with a total length of 40 cm and an effective length of 33 cm (inner diameter 75 μm). The separation temperature was room temperature and the running time was 10 min to obtain a stable baseline. The capillary electrochromatography detection performance conditions were 80% acetonitrile, 20 KV separation voltage, 50 mbar injection pressure, 4 s injection time, 10 mM buffer solution (composed of NaH2PO4 and Na2HPO4) pH 7.8, and all capillary electrochromatography data were collected and analyzed at 225 nm. The results are as follows. Figure 6 As shown, the new capillary coated column separation system achieved baseline separation for the chiral separation of the racemic drug / compound amlodipine with a resolution as high as 5.08.

[0046] Example 2

[0047] The preparation method of the capillary electrochromatographic column is the same as that of Example 1. The application of the capillary electrochromatographic separation of amlodipine (racemic) is as follows: dissolve amlodipine in a mixed solution of water and methanol (1:1, V / V) at a concentration of 0.5 mg / mL. All solutions (including test samples) are filtered through a 0.45 μm organic filter membrane. An empty quartz capillary column with a total length of 40 cm and an effective length of 33 cm (inner diameter of 75 μm) is used in the experiment. The separation temperature is room temperature and the running time is 10 min to obtain a stable baseline. The capillary electrochromatographic detection performance conditions are acetonitrile 80%, separation voltage 20 KV, injection pressure 50 mbar, injection time 3 s, 10 mM buffer solution (constituents are NaH2PO4 and Na2HPO4) pH 7.6, and all capillary electrochromatographic data are collected and analyzed at 225 nm.

[0048] Example 3

[0049] The preparation method of the capillary electrochromatographic column is the same as that of Example 1. The application of capillary electrochromatographic separation of amlodipine (racemic) is as follows: dissolve amlodipine in a mixed solution of water and methanol (1:1, V / V) at a concentration of 0.5 mg / mL. All solutions (including test samples) are filtered through a 0.45 μm organic filter membrane. The total length of the empty quartz capillary column used in the experiment is 40 cm, the effective length is 33 cm (inner diameter 75 μm), the separation temperature is room temperature, and the running time is 10 min to obtain a stable baseline. The capillary electrochromatographic detection performance conditions are acetonitrile 80%, separation voltage 20 KV, injection pressure 50 mbar, injection time 4 s, 10 mM buffer solution (constituents are NaH2PO4 and Na2HPO4) pH 7.6, and all capillary electrochromatographic data are collected and analyzed at 225 nm.

[0050] Example 4

[0051] The preparation method of the capillary electrochromatographic column is the same as that of Example 1. The application of capillary electrochromatographic separation of amlodipine (racemic) is as follows: dissolve amlodipine in a mixed solution of water and methanol (1:1, V / V) at a concentration of 0.5 mg / mL. All solutions (including test samples) are filtered through a 0.45 μm organic filter membrane. An empty quartz capillary column with a total length of 40 cm and an effective length of 33 cm (inner diameter of 75 μm) is used in the experiment. The separation temperature is room temperature and the running time is 10 min to obtain a stable baseline. The capillary electrochromatographic detection performance conditions are acetonitrile 80%, separation voltage 20 KV, injection pressure 60 mbar, injection time 2 s, 10 mM buffer solution (constituents are NaH2PO4 and Na2HPO4) pH 7.6, and all capillary electrochromatographic data are collected and analyzed at 225 nm.

[0052] Example 5

[0053] The preparation method of the capillary electrochromatographic column is the same as that of Example 1. The application of capillary electrochromatographic separation of amlodipine (racemic) is as follows: dissolve amlodipine in a mixed solution of water and methanol (1:1, V / V) at a concentration of 0.5 mg / mL. All solutions (including test samples) are filtered through a 0.45 μm organic filter membrane. An empty quartz capillary column with a total length of 40 cm and an effective length of 33 cm (inner diameter of 75 μm) is used in the experiment. The separation temperature is room temperature and the running time is 10 min to obtain a stable baseline. The capillary electrochromatographic detection performance conditions are 80% acetonitrile, a separation voltage of 20 KV, an injection pressure of 50 mbar, and an injection time of 3 s. A 10 mM buffer solution (constituents are NaH2PO4 and Na2HPO4) pH 7.8 is used, and all capillary electrochromatographic data are collected and analyzed at 225 nm.

[0054] Example 6

[0055] The preparation method of the capillary electrochromatographic column is the same as that of Example 1. The application of capillary electrochromatographic separation of amlodipine (racemic) is as follows: dissolve amlodipine in a mixed solution of water and methanol (1:1, V / V) at a concentration of 0.5 mg / mL. All solutions (including test samples) are filtered through a 0.45 μm organic filter membrane. The total length of the empty quartz capillary column used in the experiment is 40 cm, the effective length is 33 cm (inner diameter 75 μm), the separation temperature is room temperature, and the running time is 10 min to obtain a stable baseline. The capillary electrochromatographic detection performance conditions are acetonitrile 80%, separation voltage 20 KV, injection pressure 40 mbar, injection 4 s, 10 mM buffer solution (constituents are NaH2PO4 and Na2HPO4) pH 7.6, and all capillary electrochromatographic data are collected and analyzed at 225 nm.

[0056] Comparative Example 1:

[0057] First, rinse the capillary with 1M NaOH for 1 hour, 1M H2O for 5 minutes, and 1M HCl for 30 minutes. Then rinse with deionized water until neutral, rinse with methanol for 30 minutes, and blow dry with N2. After the treatment, place the capillary column in a forced air drying oven at 100°C for 1 hour. After the drying time is over, take it out for use.

[0058] A mixture of Co(ClO4)2·6H2O (6.6 mmol, 2.420 g), L-tryptophan (6.6 mmol, 1.320 g), isonicotinic acid (6.6 mmol, 0.792 g), ethanol (22 mL) and water (2.2 mL) was transferred into a 50 mL autoclave. The autoclave was then sealed and heated at 120 °C for 5 days. After cooling, the red block crystals were collected and washed with ethanol. Finally, the crystals were dried under ambient conditions.

[0059] 0.6 mg Co2(L-Trp)(INT)2(H2O)2(ClO4) was added into 1 mL deionized water and dispersed evenly by ultrasonication for 5 min. 0.5 mg L-amlodipine monomer was added into 0.5 mL of the above solution and shaken for 3 min.

[0060] The obtained sample was injected into the capillary that had been activated in step (1), and the two ends were sealed and incubated at room temperature for 16 hours. After the reaction was completed, it was rinsed with a rinse solution (methanol / acetic acid, 9:1, V / V) for 2 hours to remove the template molecule.

[0061] Amlodipine was dissolved in a mixture of water and methanol (1:1, V / V) at a concentration of 0.5 mg / mL. All solutions (including test samples) were filtered through a 0.45 μm organic filter membrane. An empty quartz capillary column with a total length of 40 cm and an effective length of 33 cm (inner diameter 75 μm) was used for the experiment. The separation temperature was room temperature and the running time was 10 min to obtain a stable baseline. The capillary electrochromatographic detection performance conditions were acetonitrile 80%, separation voltage 20 KV, injection pressure 50 mbar, injection 4 s, 10 mM buffer solution (composed of NaH2PO4 and Na2HPO4) pH 7.8, and all capillary electrochromatographic data were collected and analyzed at 225 nm.

[0062] Comparative Example 2:

[0063] First, rinse the capillary with 1M NaOH for 1 hour, 1M H2O for 5 minutes, and 1M HCl for 30 minutes. Then rinse with deionized water until neutral, rinse with methanol for 30 minutes, and blow dry with N2. After the treatment, place the capillary column in a forced air drying oven at 100°C for 1 hour. After the drying time is over, take it out for use.

[0064] 0.5 mg of levamlodipine monomer and 10 μL of APTES were dissolved in 7.5 mL of a mixture of ethanol / water (2:1, V / V) and magnetically stirred for 30 min. After stirring, 10 μL of TEOS and 10 μL of NH 3 ·H 2 O were added to the above solution and shaken for 3 min.

[0065] The obtained sample was injected into the capillary that had been activated in step (1), and the two ends were sealed and incubated at room temperature for 16 hours. After the reaction was completed, it was rinsed with a rinse solution (methanol / acetic acid, 9:1, V / V) for 2 hours to remove the template molecule.

[0066] Amlodipine was dissolved in a mixture of water and methanol (1:1, V / V) at a concentration of 0.5 mg / mL. All solutions (including test samples) were filtered through a 0.45 μm organic filter membrane. An empty quartz capillary column with a total length of 40 cm and an effective length of 33 cm (inner diameter 75 μm) was used for the experiment. The separation temperature was room temperature and the running time was 10 min to obtain a stable baseline. The capillary electrochromatographic detection performance conditions were acetonitrile 80%, separation voltage 20 KV, injection pressure 50 mbar, injection 4 s, 10 mM buffer solution (composed of NaH2PO4 and Na2HPO4) pH 7.8, and all capillary electrochromatographic data were collected and analyzed at 225 nm.

[0067] Example 1 is compared with the capillary coated columns using CMOFs and CMIPs as stationary phases in Comparative Examples 1 and 2 (eg Figure 7 As shown, the strategy of using the new nanomaterial synthesized with CMOFs and CMIPs to prepare the stationary phase of the CEC column in Example 1 is highly innovative. CMOFs and CMIPs produce a synergistic effect, which greatly improves the chiral selectivity of the new nanomaterial; the CMOFs nanomaterial with a huge specific surface area greatly increases the loading capacity of CMIPs, and the rigid skeleton of CMOFs can effectively prevent the collapse and deformation of the imprinted cavity of CMIPs; CMIPs can also improve the connection stability of the capillary coating column stationary phase. Compared with the capillary coating columns in Comparative Examples 1 and 2 using CMOFs and CMIPs alone as stationary phases, the chiral separation performance of L-AM@CMIP(APTES-TEOS)@Co2(L-Trp)(INT)2(H2O)2(ClO4)@capillary prepared by the present invention is greatly improved (separation degree: 0 / 0→5.08).

[0068] The above is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and changes can be made without departing from the principle of the present invention, and these improvements and changes are also regarded as the protection scope of the present invention.

Claims

1. A method for preparing a nanomaterial capillary electrochromatographic column synthesized based on CMOFs and CMIPs, characterized in that: The following steps are involved: (1) Rinse the quartz capillary and blow dry to obtain a pretreated capillary; (2) Co(ClO4)2·6H2O, L-tryptophan, isonicotinic acid, water and ethanol were mixed and added into a reactor, the reactor was sealed, heated at 120°C for 5 days, and after cooling, the crystals were collected, washed and dried to obtain Co2(L-Trp)(INT)2(H2O)2(ClO4), wherein the molar ratio of Co(ClO4)2·6H2O, L-tryptophan and isonicotinic acid was 1:1:1; (3) 0.6 mg Co2(L-Trp)(INT)2(H2O)2(ClO4) was added to 1 mL deionized water and ultrasonicated for 5 min to make it uniformly dispersed. 0.5 mg levoamlodipine monomer and 10 μL APTES were added to 7.5 mL of ethanol / water mixture and magnetically stirred for 30 min. After stirring, 0.5 mL Co2(L-Trp)(INT)2(H2O)2(ClO4) dispersion, 10 μL TEOS and 10 μL NH3·H2O were added to the above solution and shaken for 3 min to obtain L-AM@CMIP(APTES-TEOS)@Co2(L-Trp)(INT)2(H2O)2(ClO4); (4) Injecting the sample obtained in step (3) into the capillary pretreated in step (1), sealing both ends and incubating at room temperature. After the incubation is completed, flushing with a flushing solution to remove the template molecules to obtain L-AM@CMIP(APTES-TEOS)@Co2(L-Trp)(INT)2(H2O)2(ClO4)@capillary.

2. The preparation method according to claim 1, characterized in that: In the step (1), the capillary column is an empty quartz capillary with an inner diameter of 75 microns and a total length of 40 cm.

3. The preparation method according to claim 1, characterized in that: In step (1), the steps for pretreating the capillary are as follows: first rinse the capillary with NaOH for 1 hour, rinse the capillary with H2O for 5 minutes, rinse the capillary with HCl for 30 minutes, then rinse with deionized water until neutral, rinse with methanol for 30 minutes and then blow dry with N2. After the treatment, the capillary column is placed in a forced air drying oven and dried at 100°C for 1 hour.

4. The preparation method according to claim 3, characterized in that: The concentrations of NaOH solution and HCl solution are both 1 mol.L -1 .

5. The preparation method according to claim 1, characterized in that: In the step (3), the volume ratio of ethanol to water in the ethanol / water mixture is 2:

1.

6. The preparation method according to claim 1, characterized in that: In the step (4), the incubation time is 16 hours.

7. The preparation method according to claim 1, characterized in that: In the step (4), the flushing liquid is a mixture of methanol / acetic acid with a volume ratio of 9:1, and the flushing time is 2 hours.

8. Use of the capillary electrochromatographic column prepared by the preparation method according to any one of claims 1 to 7 in the separation of amlodipine by capillary electrochromatography.

9. The use according to claim 8, characterized in that: The injection process is as follows: amlodipine is added to a mixed solution of water and methanol to prepare a solution with a concentration of 0.5 mg / mL, and the solution is filtered through a 0.45 μm organic filter membrane, wherein the volume ratio of water to methanol is 1:

1.

10. The use according to claim 8, characterized in that: The conditions for separating amlodipine by capillary electrochromatography are: 10 mM NaH2PO4 / Na2HPO4 buffer, separation voltage 20 KV, room temperature, injection pressure 40-60 mbar, injection time 2-4 s, detection wavelength 225 nm, running time 10 min, wherein the pH of the buffer solution is 7.6 or 7.8.

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