457 results about "Stationary phase" patented technology

The invention discloses an organic sample analysis method based on micro gas chromatography and a chromatographic analyzer, particularly relates to the technical field of micro gas chromatography, and is used for solving the problems of unstable separation performance and low complex sample detection precision caused by insufficient uniformity of a stationary phase coating of an existing micro chromatographic column. The method comprises the following steps: constructing a stationary phase distribution initial profile by continuously pre-charging carrier gas, alternately applying segmented temperature gradient, micro-negative pressure and directional pulse flow to remodel a uniform distribution layer, generating a correction factor set of a temperature-resistance coupling relationship by combining a correction mixture and a tracer gas pulse, dynamically adjusting a carrier gas flow velocity and a temperature program to generate a matched operation curve, and finally, carrying out dynamic calibration. High-precision separation detection and quantitative analysis are achieved, stable separation performance is maintained in a miniaturized structure by cooperatively controlling stationary phase distribution optimization and real-time parameter feedback correction, and the detection precision and reproducibility of a wide-boiling-range organic mixture are improved.

The invention discloses a fruit and vegetable exosome extraction method based on ligand fishing. The fruit and vegetable exosome extraction method comprises the following steps: suspending amino-functionalized Fe3O4 (at) SiO2 nanoparticles in a glutaraldehyde solution, and adding activated agglutinin to obtain Fe3O4 (at) SiO2-agglutinin nanoparticles; adding a glutaraldehyde solution into agarose gel to obtain a size exclusion chromatographic column filler; the method comprises the following steps: dispersing Fe3O4 (at) SiO2-lectin nanoparticles in a PBS buffer solution to obtain a uniform suspension, adding the uniform suspension into a size exclusion chromatographic column filler to obtain a uniform slurry, filling the size exclusion chromatographic column with the uniform slurry, and flushing with the buffer solution to form a magnetic bead stationary phase; and loading fruit and vegetable supernatant into a size exclusion chromatographic column, passing through the magnetic bead stationary phase, cleaning residual impurities combined on the exosome-magnetic bead compound by using a buffer solution, and dissociating the exosome from the magnetic beads by using a competitive eluent of the exosome to obtain the high-purity fruit and vegetable exosome. The problem that an existing exosome extraction method is difficult to meet the requirements of high efficiency, simplicity, high purity and high activity at the same time is solved.

The invention discloses a construction method and an identification method of characteristic chromatograms of a senecio scandens medicinal material as well as decoction pieces, standard decoction and formula granules thereof, and relates to the technical field of traditional Chinese medicine identification. The construction method of the specific chromatogram comprises the following steps: extracting a to-be-detected sample with methanol to obtain a test solution; the method comprises the following steps: dissolving 5-caffeoylquinic acid, chlorogenic acid, caffeic acid, 4-caffeoylquinic acid, rutin, hyperoside, isoquercitrin and 4, 5-dicaffeoylquinic acid with methanol to obtain a reference solution; and a liquid chromatograph is adopted for determination. A chromatographic column of the liquid chromatograph takes phenyl-methyl polysiloxane as a stationary phase, acetonitrile as a mobile phase A and 0.05 vol%-0.3 vol% formic acid aqueous solution as a mobile phase B for gradient elution. The information of the characteristic chromatogram constructed by the method is rich, and the quality of the senecio scandens medicinal material, decoction pieces, standard decoction and formula granules can be quickly and comprehensively reflected.

The invention discloses a strong-hydrophobicity chromatographic stationary phase modified by a covalent triazine skeleton containing an octyl chain as well as a preparation method and application of the strong-hydrophobicity chromatographic stationary phase. Activated silica gel is modified by utilizing a silane coupling agent, so that gamma-glycidyl ether oxypropyl trimethoxy is introduced into the surface of the silica gel; and performing in-situ growth of a covalent triazine skeleton layer containing an octyl chain through a Schiff base condensation reaction to prepare the strong-hydrophobicity chromatographic stationary phase. A covalent triazine skeleton containing a hydrophobic octyl chain in the structure is used for modifying the surface of silica gel, and a bonding phase contains a triazine ring, a benzene ring, an octyl chain and an amino group. According to the stationary phase, a hydrophobic long octyl chain is introduced into a bonding unit of CTF, so that the structure, morphology and performance of the CTF are changed, a'flower-on-sphere 'morphology is formed, and the stationary phase has a rigid porous structure, adjustable hydrophilicity / hydrophobicity, a rich pi electron system, strong hydrophobicity and good separation selectivity for non-polar compounds, and can be widely applied to separation of various samples.

The invention provides a method for separating EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) through supercritical fluid chromatography, and relates to the technical field of separation and purification. The invention provides a method for separating EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) by supercritical fluid chromatography, which comprises the following steps: by taking supercritical carbon dioxide and an organic reagent as mobile phases, and by utilizing the specific mobile phase property of supercritical CO2 after being mixed with the organic reagent (saturated aliphatic hydrocarbon) and matching with a normal-phase chromatographic column, separating the EPA from the DHA by supercritical fluid chromatography. A specific stationary phase (one or more of a silica gel surface bonded propylurea stationary phase, a silica gel surface bonded phenyl stationary phase and a silica gel surface bonded imidazolyl stationary phase) is adopted, effective separation and preparation of the EPA and the DHA in the fish oil can be achieved, the EPA and the DHA in the fish oil can be effectively separated within 50 min, the separation speed is high, the separation effect is good, and the method is suitable for industrial production. The purity of the obtained EPA and DHA is 98% or above, the purity of the EPA and the DHA is high, and the EPA and the DHA have good application prospects in the fields of medicine production and food and health care products.

The invention belongs to the technical field of chromatographic separation materials, and discloses a preparation method and application of a GM-8 nanosheet material. The preparation method of the material comprises the following steps: respectively dissolving Cu (NO3) 2.3 H2O and 1, 3, 6, 8-tetra (4-carboxybenzene) pyrene in an organic solvent, mixing, transferring into a reaction bottle, adding trifluoroacetic acid and pyridine, and uniformly mixing and stirring to obtain a reaction mixture; and heating the reaction mixture to react for 7-9 hours to obtain a blue precipitate, cooling the blue precipitate to room temperature, and washing and drying the blue precipitate to obtain the ultra-stable microporous GM-8 nanosheet material. The nanosheet GM-8 is used as a gas chromatography stationary phase, high-efficiency separation and trace detection of xylene isomers can be realized, and the chromatographic column still keeps excellent separation capacity after being stored in an environment with air humidity of 65-90% for 31 months. The capillary gas chromatographic column can realize high-efficiency separation of disubstituted benzene isomers such as xylene, the separation degree of m-xylene / p-xylene is up to 18.2, and a new solution is provided for high-efficiency separation of isomers with similar properties.

Gas chromatography (GC) relies on the interaction of vapor molecules with the stationary phase coated on the column inner wall to separate different vapor molecules. Here, graphene is integrated as the ultrathin and electrically tunable stationary phase within a GC column. Graphene has different interactions with different vapor molecules, which leads to separation of those vapor molecules. In addition, by configuring graphene into a field effect transistor (FET) design, the molecule-graphene interaction can be controlled or tuned by adjusting the graphene Fermi level through the FET gate voltage. As a result, the binding energy between graphene and adsorbed vapor molecules can be tuned and hence the elution time and / or elution order of vapor molecules can be changed.

The invention discloses a preparation method of a dehydroabietic acid cellulose ester (DCE) bonded silica gel stationary phase, which comprises the following steps: firstly, carboxylating the surface of a SiO2 microsphere with a core-shell structure, then carrying out acylating chlorination, and then preparing amphiphilic DCE coated SiO2 solid particles with DCE in a chemical bonding manner. The DCE-SiO2 solid particle has the pore diameter of 5-30nm and the specific surface area of 50-400m < 2 > / g, has the characteristics of intact particle shape, uniform particle size, high mechanical strength, high pressure resistance and the like, and can be used as a liquid chromatographic column filler. The preparation method is simple and convenient, the column pressure is low, the repeatability is good, the chemically modified DCE has a phenanthrene ring skeleton and has good selective separation performance on saponin drugs containing ring structures, and the application prospect in the pharmaceutical industry is wide.

A method for separating and purifying 4MP1 from a mixture containing 4MTP2 and 1-Hexene comprises the following steps: continuously introducing a solution in which 4MTP2, 1-Hexene and 4MP1 with any concentration are dissolved into a simulated moving bed chromatography system as a raw material solution, collecting a high-purity 4MP1 solution from raffinate of the simulated moving bed chromatography system by adopting a metal organic framework material as a stationary phase, and separating the high-purity 4MP1 solution from the raffinate of the simulated moving bed chromatography system. The extraction liquid is a solution containing impurities 4MTP2 and 1-Hexene. The invention provides a brand new method for separating 4MP1 from 4MTP2 and 1-Hexene, and a complete separation scheme is provided for the prior art; in the separation of high-concentration 4MP1, the relative purity of the separated and purified 4MP1 can reach gt; the recovery rate is gt; and in the separation of low-concentration 4MP1, the rectification level is also exceeded, and the method is more suitable for 4MP1 thermosensitive substances.

The invention discloses a stationary phase of a novel zwitterionic monomer containing a multi-charge structure as well as a preparation method and application of the stationary phase, and belongs to the technical field of hydrophilic interaction chromatography (HILIC) stationary phases. According to the method, multi-charge zwitterions are used as hydrophilic monomers, the multi-charge structure of the multi-charge zwitterions endows the monomers with higher hydrophilic performance, and the multi-charge zwitterions are immobilized on the surface of a matrix by utilizing an active free radical polymerization method, so that a series of novel super-hydrophilic HILIC stationary phases are finally prepared. The multi-charge zwitterionic monomer adopted by the invention not only has better hydrophilic performance and higher charge density, but also can efficiently, simply and conveniently realize matrix surface grafting and modification. The developed stationary phase is suitable for HILIC column chromatography separation analysis, and the HILIC chromatographic performance can be greatly improved; the method can also be applied to the fields of biological sample pretreatment, material science, marker clinical diagnosis and the like, and has high economic and social values.

A 3,5,5-trimethylhexanoic acid composition containing 3,5,5-trimethylhexanoic acid and t-butyl alcohol in which the t-butyl alcohol concentration in terms of toluene-d8 measured by gas chromatography-olfactometry / mass spectrometry under the conditions below exceeds 0 ppb by volume and is 200 ppb by volume or less is provided. The composition is excellent in sulfuric acid coloring evaluation,(Measurement Conditions)The 3,5,5-trimethylhexanoic acid composition is concentrated, andThe concentrated sample is measured by gas chromatography-olfactometry using a column using dimethylpolysiloxane as a stationary phase, and the structure of a measured component is analyzed with a mass spectrometry detector.

The present invention belongs to the technical field of purification of polypeptide drugs, and specifically relates to a method for purifying tilpotide, comprising: (a) preparing a crude tilpotide solution using an acetonitrile aqueous solution; (b) selecting a specific stationary phase, mobile phase, and elution gradient to purify the crude tilpotide solution for a first time to obtain a first fraction; (c) selecting a specific stationary phase, mobile phase, and elution gradient to purify the first fraction for a second time to obtain a second fraction; (d) performing nanofiltration concentration, salt exchange, filtration sterilization, and lyophilization on the second fraction to obtain the tilpotide product. The product obtained by the purification method of the present invention has a purity of more than 99.5%, and the total recovery rate of purification is more than 80%. The single-needle elution cycle of the present invention is only 35 to 40 minutes, which greatly reduces the use of organic solvents in the purification process of tilpotide, reduces purification costs, and is more environmentally friendly in the long term.

The invention provides ester group functionalized cyclotriveratrum hydrocarbon as well as a preparation method and application thereof, and relates to the technical field of gas chromatographic analys.According to the ester group functionalized cyclotriveratrum hydrocarbon and the preparation method and application thereof, a long alkyl chain and an ester group are introduced to the lower edge of cyclotriveratrum hydrocarbon, so that the property of the cyclotriveratrum hydrocarbon serving as a gas chromatographic stationary phase is improved; by introducing a non-polar alkyl chain and a polar ester group, the melting point of the cyclotriveratrum hydrocarbon can be reduced, the film-forming property and the thermal stability of the cyclotriveratrum hydrocarbon are improved, and the separation performance of the cyclotriveratrum hydrocarbon serving as a stationary phase of a capillary gas chromatographic column on an analyte is improved; the method can effectively separate methyl benzaldehyde isomers, bromobenzaldehyde isomers, nitrobenzaldehyde isomers, diethylbenzene isomers, benzene series, homologues, cis-trans isomers and multi-component complex mixtures.

The invention relates to a honeycomb-shaped novel COF (Covalent Organic Framework) functionalized silicon-based chromatographic stationary phase. Silica gel is used as a matrix, and TAPT (Triallyl Phosphate) and DMTP (Dimethyl Tricarbonyl Phosphate) are subjected to aldehyde amine condensation reaction to form a two-dimensional The synthesis method comprises the following steps: activating silica gel particles by using hydrochloric acid, and neutralizing gamma-GPTS by using the activated spherical silica gel particles and anhydrous toluene to synthesize SiO2-GPTS; tAPT and DMTP are used as raw materials, a two-dimensional covalent organic framework COF is formed through a Schiff base aldehyde amine condensation reaction, and a novel honeycomb-shaped COF functionalized silicon-based chromatographic stationary phase SiO2 (at) TAPT-DMTP-COF is formed through coordination of silicon hydroxyl and amino / aldehyde group of a COF skeleton. When the TAPT-DMTP-COF is applied to chromatographic column separation, the TAPT-DMTP-COF has a porous structure with plane pi conjugation, height orderliness and stability, and the specific structure of the TAPT-DMTP-COF enables fixed relative shape limited isomers, geometric isomers and positional isomers to show excellent selectivity and separation capacity; the surface of SiO2 is coated with the COF-modified high performance liquid chromatography stationary phase material, so that the COF-modified high performance liquid chromatography stationary phase material has a uniform honeycomb shape, and a new way is opened up for constructing the COF-modified high performance liquid chromatography (HPLC) stationary phase material with the uniform shape.

This invention discloses an analytical method for benzothiazole contaminants, comprising the following steps: detection by high performance liquid chromatography (HPLC), with the following chromatographic conditions: a phenylhexyl column as the stationary phase, mobile phase A being water, mobile phase B being acetonitrile, and gradient elution; wherein the benzothiazole contaminants are at least one of 2-aminobenzothiazole, 2-hydroxybenzothiazole, benzothiazole, 2-methylbenzothiazole, 2-mercaptobenzothiazole, 2,5-dimethylbenzothiazole, 2-cyanobenzothiazole, ethyl 2-carboxylate benzothiazole, 2-chlorobenzothiazole, 2-bromobenzothiazole, 2-methylthiobenzothiazole, phenylthiocyanate, N-tert-butyl-2-benzothiazole sulfenamide, 2-(2-hydroxyphenyl)-benzothiazole, N-cyclohexyl-2-benzothiazole sulfinamide, dibenzothiazole disulfide, and N,N-dicyclohexyl-2-benzothiazole sulfonamide.

The invention relates to the technical field of floridoside and an isomer monomer thereof, and discloses a method for preparing high-purity floridoside and an isomer monomer thereof on a large scale, which is used for carrying out large-scale preparation and purification research on the high-purity floridoside and the isomer monomer thereof and preparing the floridoside and the isomer monomer thereof from a porphyra haitanensis crude extract. And the structure and purity of the compound are identified. The method comprises the following steps: firstly, by utilizing a DART-MS technology, through a single factor experiment, optimizing experiment parameters such as extraction times and elution, and obtaining optimal extraction efficiency; and secondly, based on a two-step purification method of a prep-HPLC (Prep-High Performance Liquid Chromatography) technology, enriching the target compound by using a reversed-phase (C18) mode stationary phase in the first step, and separating the pair of isomers by using a normal-phase (NH3) mode stationary phase in the second step. The obtained floridoside and isomer monomers thereof are subjected to structure and purity identification by mass spectrometry (MS) and nuclear magnetism (NMR). Results are as follows: the two compounds are identified as floridoside and isomers thereof through high-resolution mass spectrometry, and the purities of the floridoside and the isomers thereof are up to 99.5% or above.

The invention provides a micro-plastic filling permeation immersion type interface coupling reaction experiment device which comprises a rectangular frame, a reaction column cylinder, a T-shaped strip and an iron convex block, a piston rod is movably arranged in the reaction column cylinder, a material guide pipe is arranged at the upper end of the right side of the reaction column cylinder, and a micro plug valve is arranged at a liquid inlet in the lower end of the reaction column cylinder. Guide grooves are formed in the left side and the right side of the interior of the rectangular frame, a magnetic block is installed on the upper portion of the interior of the rectangular frame, a U-shaped iron frame is fixed to the upper end of the right side of an iron protruding block, and a positioning rod is installed at the right end of the lower portion of the U-shaped iron frame in a penetrating and sliding mode. And the reaction solution uniformly permeates through the filling layer by utilizing the negative pressure of the driving core, so that the full-domain immersion type full contact between the micro plastic particles and the reaction solution is realized.

The application relates to the technical field of isotope separation, in particular to a SiO2@CeO2 core-shell material with silica supported cerium dioxide, a preparation method thereof and application of the SiO2@CeO2 core-shell material in Ge / Ga separation. 68 Efficient adsorption of Ge and 68 Effective elution of Ga; the SiO2@CeO2 core-shell material is used as a stationary phase, hydrochloric acid is used as a mobile phase, Ge / Ga is efficiently separated based on solid-phase extraction, and therefore the SiO2@CeO2 core-shell material can be used as 68 Ge- 68 Ga generator column packing.

To provide a method capable of separating a monofunctional species, bifunctional species, etc. of a fluorinated ether compound having a polyfluoropolyether chain and a predetermined functional group in good yield and with high separation performance.A separation method for separating a compound represented by the formula (1) and a compound represented by the formula (2) from a mixture containing them by chromatography using a stationary phase and a mobile phase, wherein the mobile phase contains at least one type of specific solvent selected from a hydrofluoroolefin, a hydrochlorofluoroolefin, a chlorofluoroolefin, a cyclic hydrofluoroolefin, a cyclic hydrochlorofluoroolefin, a cyclic chlorofluoroolefin, a cyclic hydrofluorocarbon, a cyclic hydrochlorofluorocarbon, a cyclic chlorofluorocarbon and a perfluoroketone:A-(OX)m—O—Z—(R)n1  Formula (1)(R)n2—Z—(OX)m—O—Z—(R)n3  Formula (2)

The invention discloses radioactive gas separation and purification equipment, a radioactive gas separation and purification method, a radioactive gas separation and purification medium and radioactive gas separation and purification equipment, and relates to the technical field of radioactive gas separation and purification. The radioactive gas separation and purification equipment comprises a first separation column, a second separation column, a carrier gas container, a quantitative structure, a chromatographic column, a detection assembly, a first control valve, a storage container, a temperature controller and a to-be-treated gas container. The carrier gas container is connected with the first control valve, and the to-be-treated gas container, the quantitative structure, the first control valve, the first separation column, the second separation column, the chromatographic column and the storage container are sequentially connected. The first separation column, the second separation column and the chromatographic column are all filled with stationary phases which are all used for purifying target substances in the to-be-treated gas based on different adsorption rates of the stationary phases relative to different substances. Therefore, due to the arrangement of the first separation column, the second separation column and other structures, large-volume ambient air or gaseous effluent can be purified, and subsequent radioactive substance concentration measurement is facilitated.

The invention discloses an immobilized artificial membrane chromatography (IAMC) stationary phase as well as a preparation method and application thereof, and belongs to the technical field of bionic chromatography stationary phases. According to the method, a matrix containing an initiating group is used as an initiator, under the action of a catalyst, a phospholipid monomer is fixed on the surface of the matrix by utilizing an active free radical polymerization method, and the stable IAMC stationary phase is formed. According to the method, the phospholipid can be efficiently, simply and conveniently grafted on the surface of the silica gel matrix, and the prepared stationary phase has good acid-base stability and bionic property. The IAMC stationary phase provided by the invention has a wide application prospect, can greatly improve the application potential of a chromatographic technology in the fields of life science, environmental protection, drug research and development and the like, and has relatively high economic and social values.

A chromatography system is provided. The chromatography system is configured to process a feed fluid containing a plurality of components, wherein at least one component of the plurality of components of the feed fluid is a target component. The chromatography system comprises: a flow path comprising a plurality of fluid control components configured to control a fluid flow; a stationary phase, wherein the stationary phase is at least one membrane adsorber connected to the flow path and the stationary phase is configured to isolate the target component. The flow path is configured such that harvesting of the target component is optimized.

The utility model provides an environment-friendly row type pigment chromatography device which comprises chromatography tubes, a flow divider and an injector, the chromatography tubes are used for loading a stationary phase, the bottoms of the multiple chromatography tubes are communicated with the flow divider so that the multiple chromatography tubes can be connected to the flow divider in parallel, the injector is used for loading chromatography liquid, and the flow divider is communicated with the flow divider so that the multiple chromatography tubes can be connected to the flow divider in parallel. And the output end of the injector is communicated with the flow divider. According to the invention, multiple groups of pigment chromatography experiments can be completed at one time through the multiple parallel chromatography tubes, and multiple samples can be treated at the same time, so that time and resources are saved, and the experiment efficiency is improved; meanwhile, the environment-friendly row type pigment chromatography device has good air tightness, leakage of poisonous gas in the experiment process can be avoided, after the experiment is finished, chromatography liquid can be recycled through an injector and can be reused, waste liquid discharge is reduced, pollution to the environment is reduced, and the purposes of energy conservation and environment protection are achieved.

The invention discloses a method for simultaneously measuring the concentrations of hydantoin and hydantoin acid based on liquid chromatography, which comprises the following steps: respectively weighing hydantoin and hydantoin acid standard substances, dissolving with a solvent, fixing the volume, shaking uniformly and filtering to prepare a standard substance solution; taking a to-be-detected sample, dissolving the to-be-detected sample with a solvent, fixing the volume, uniformly shaking, filtering to prepare a sample solution, taking the standard substance solutions and the sample solution with different concentrations, respectively carrying out automatic sample injection analysis through a high performance liquid chromatography automatic sample injector, and recording a chromatogram map; establishing a linear regression curve by taking the concentration of the standard substance as an abscissa and the peak area in the chromatogram as an ordinate; and substituting the peak area of the sample to be detected into the linear regression curve to obtain the content of hydantoin and hydantoic acid. According to the present invention, by using the hydrophobic difference caused by the molecular structures of the hydantoin and the hydantoic acid, the retention behavior of the hydantoin and the hydantoic acid on the chromatographic column stationary phase can be adjusted by accurately optimizing the chromatographic conditions, particularly the organic phase / water phase ratio in the mobile phase, such that the efficient and rapid baseline separation is achieved;

The application belongs to the technical field of medical detection, and particularly relates to a method for detecting metaraminol enantiomers in injection. The method comprises detecting metaraminol enantiomers in injection by high performance liquid chromatography, wherein the detection conditions of the high performance liquid chromatography comprise: a chromatographic column adopts a packing material with a polysaccharide derivative bonded on the surface of silica gel as a stationary phase; and a mixed solution of n-hexane, anhydrous ethanol and ethylenediamine is used as a mobile phase. The method has good separation degree and high separation efficiency. Through complete methodology verification, the method can effectively, accurately and stably detect the content of metaraminol enantiomers, and is beneficial to improving the safety of clinical medication.

The application discloses a kind of cell membrane chromatographic column based on biotin ligase directional covalent fixation and its preparation method and application, belong to chromatography science and technology field. By bonding 2-imino biotin to silica gel, then using biotin ligase specific recognition with Avi-Tag cell membrane fragments, and stable covalent bonding occurs with 2-imino biotin silica gel, so that cell membrane is fixed on the surface of silica gel to obtain Avi-Tag bridged cell membrane chromatographic stationary phase, finally using wet column packing, obtain cell membrane chromatographic column based on biotin ligase directional covalent fixation. The cell membrane chromatographic column can prolong the service life of cell membrane chromatographic column, improve the stability of cell membrane chromatographic column during use, and the short peptide tag (Avi-Tag) used can improve the non-specific adsorption and poor specificity of the cell membrane chromatographic column prepared based on protein tag technology to a certain extent, providing technical support for the wide application of cell membrane chromatographic column.

The invention discloses a method for detecting 5 '(E)-VPA phosphoramidite monomer related substances, and belongs to the technical field of liquid chromatography detection. Related substances comprise 5 '-(E)-VP-2'-OMe-A (Bz), 5 '(Z)-VPA, 5'-(E)-VP-2 '-OMe-A-CE-P and 5' (E)-VPA-OX, and chromatographic detection conditions comprise that the column temperature is 23-27 DEG C, a stationary phase of a chromatographic column is octadecyl bonded silica gel, a mobile phase A is an ammonium acetate solution, a mobile phase B is acetonitrile, gradient elution is performed, and the like. According to the method, four related substances in the 5 '(E)-VPA phosphoramidite monomer are effectively separated through specific liquid chromatography conditions, the system adaptability, specificity, linearity and range, detection limit, quantitation limit and accuracy verification of the method all meet acceptable standards of pharmacopoeia, and detection of multiple related substances can be completed within a short time; and a reliable means is provided for detecting and controlling the quality of the 5 '(E)-VPA phosphoramidite monomer.

A method of monitoring a chemical process in a column apparatus using a measurement system is disclosed, the column apparatus being configured to contain a solid stationary phase, receive a liquid mobile phase, and enable flow of the mobile phase through the stationary phase in a flow direction. The measurement system comprises a set of electrodes arranged at a sensing location of the column apparatus. The method comprises: providing the solid stationary phase within the column apparatus; causing the liquid mobile phase to flow through the stationary phase in a flow direction; applying an electrical stimulation to the set of electrodes; receiving an electrical signal from the set of electrodes; and determining one or more characteristics of a chemical interaction between the solid stationary phase and the liquid mobile phase by processing the electrical signal received from the set of electrodes.

According to the method, engineering microorganisms are immobilized on stationary phases such as gelatin by applying a microorganism immobilization technology, cell walls of the microorganisms are removed by applying lysozyme, and 6s-5 methyltetrahydrofolic acid in cells can be easily extracted through cell membranes under the action of a surfactant. A culture solution and an eluent are made into mobile phases, the mobile phases flow through a stationary phase containing engineering bacteria, so that the 6s-5 methyltetrahydrofolic acid is continuously extracted from microorganisms, and after the 6s-5 methyltetrahydrofolic acid is collected, the treated mobile phases such as the culture solution and the eluent are circularly input into the stationary phase to form a continuous flow production process. The continuous flow process shows a milk squeezing effect, and the concentration balance of 6s-5 methyltetrahydrofolic acid in microorganisms is broken, so that the 6s-5 methyltetrahydrofolic acid is continuously biosynthesized and output. The technical problem of low concentration of biological fermentation final products at present is solved.

The invention discloses a method for determining the content of seven genotoxic impurities in epichlorohydrin through gas chromatography-mass spectrometry, and belongs to the technical field of pharmaceutical analysis. According to the method, a quartz capillary chromatographic column taking polyethylene glycol as a stationary phase is adopted, split-flow sample injection is performed, and the genotoxic impurities in an epoxy chloropropane sample are detected by using a gas chromatography-mass spectrometry method; the genetic toxicity impurities are glycidyl, 1, 3-dichloro-2-propyl alcohol, 2, 3-dichloro-1-propyl alcohol, 3-chloro-1, 2-propylene glycol, 2-chloro-1, 3-propylene glycol, 2-chloro-2-propylene-1-alcohol, and 1, 2, 3-trichloropropane. The invention further discloses a preparation method of the compound. According to the present invention, the seven genotoxic impurities in the epoxy chloropropane can be rapidly, effectively, accurately and reliably separated and detected, and the genotoxic impurities can be controlled within the low detection range through the mass spectrometer, such that the quality of the epoxy chloropropane can be easily controlled, the product quality of the hexyl aminolevulinate hydrochloride can be easily improved, and the medication safety of the patient can be easily improved.