41 results about "Ion pair chromatography" patented technology

The invention discloses an analysis method for measuring pyrroloquinoline quinine (PQQ) content through ion pair chromatography, and belongs to the technical field of chromatographic analysis. The PQQ produced through synthesis or fermentation is quantitatively analyzed by ion pair high performance liquid chromatography, the obtained regression equation is y=4E+06X+627846, R<2>=0.9995, and is linear in a test range of 2 to 12 mu g / mL, and the minimum detectable amount is 2.0ng (S / N is more than or equal to 3). The method is simple, and possibly generated impurities in the preparation process are effectively separated.

The invention discloses a detection method for the content of iodine in a feed. The detection method comprises the following steps: (1) carrying out ion pair chromatography detection on an iodine standard solution; (2) drawing an iodine content standard curve according to a detection result in the step (1); (3) pretreating a sample to be detected before the detection of the content of the iodine; and (4) detecting the pretreated sample to be detected by adopting the method in the step (1), comparing the detection result with the standard curve, and calculating the content of the iodine in the sample to be detected. The method has a good linear relation, is easy to operate, has strong repeatability and high accuracy, and can be used for detecting the general iodine in the feed.

The present invention provides monolithic polymer matrices for the separation of bio-organic molecules by liquid chromatography. In one embodiment, the matrix is formed from a polymerization mixture including (i) a hydrophobic monomer, (ii) a crosslinking agent, and (iii) a porogenic solvent or mixture of porogenic components. The monolithic matrices of the invention are particularly useful for resolving polynucleotides (e.g., DNA and / or RNA) in samples by way of reversed-phase ion-pairing chromatography.

The invention discloses a method for an online desalination LC-MS analysis on melamine and special equipment. The method comprises the following steps: separating a sample through a reversed phase ion pair chromatography and an ion exchange chromatography and concentrating the compositions to be tested through a trapping column; washing the trapping column to remove salt or an ion pair reagent in a mobile phase; and backwashing the trapping column with a salt-free mobile phase so that the compositions to be tested enter a mass spectrum to be analyzed. The equipment is provided with a multi-port valve; a first inlet of the multi-port valve is connected with a chromatographic column and is connected with a mobile phase input pump through a sampling valve; the first inlet is also connected with a desalting cleaning liquid input pump; a first outlet of the multi-port valve is connected with a waste liquid pool; a second inlet of the multi-port valve is connected with a salt-free mobile phase input pump; the second outlet of the multi-port valve is connected with a mass spectrum detector; and the trapping column is bridged between two valve holes of the multi-port valve. The equipment has the advantages of simple structure, convenient operation and low cost, thus the reversed phase ion pair chromatography and the ion exchange chromatography can be used together with a mass spectrometric analysis.

The invention relates to a synthesis method of hydrophilic ion pair chromatography packing, which is used for preparing the chromatography packing. The method adopts the technical scheme that a mixture of monomers ethylstyrene and divinylbenzene reacts with an ion monomer, namely potassium styrene sulfonate on the surface to generate the high-crosslinking hydrophilic ethylstyrene-divinylbenzene packing containing a sulfonic acid group on the surface. The method solves the technical problems that when a large number of organic solvents are added for modifying styrene-divinylbenzene, other components of an ion chromatography analysis system are required to have high organic solvent tolerance; and when concentrated sulfuric acid sulfonation is adopted for modification, the control difficulty of a sulfonation reaction on the surface is high, the product consistency is poor, screening is required, a success rate is low and the cost is high.

The invention relates to a preparation method for an ion-pair chromatography reagent sodium heptanesulfonate. The preparation method comprises the following steps: sequentially adding anhydrous sodium sulfite, water, heptyl bromide and tetrapropylammonium bromide into a reaction vessel which is provided with a cooling reflux device and a mechanical stirrer; sulfonating for 16-24 hours; under a reducing pressure, evaporating moisture in a mixture obtained after finishing sulfonation reaction; smashing remained solid after being dried, and then adding into a Soxhlet extractor; extracting with absolute ethyl alcohol and obtaining a product, namely a rough product; re-crystallizing the rough product with the absolute ethyl alcohol; filtering for two times and then purifying, thereby obtaining a purified product; and lastly, drying the purified product for 2-4 hours, thereby obtaining an end product. According to the preparation method, during a sulfonation reaction process of sodium sulfite and heptyl bromide, the tetrapropylammonium bromide is taken as a catalyst, the activity of the heptyl bromide is enhanced, the sulfonation reaction is smoothly performed, the generation of by-products is reduced, the reaction time is obviously shortened, and the yield can reach 66%.

The invention discloses a determination method for protein powder freshness. The method comprises the following steps: firstly adding a protein powder sample into a mixed solution of a hydrochloric acid solution and an oxalic acid solution, evenly mixing, then heating the solution in a nitrogen atmosphere, cooling to room temperature, and filtering to obtain a filtrate taken as a test solution; and respectively injecting a furosine standard solution and the test solution into a high performance liquid chromatograph and carrying out detection so as to obtain the content of furosine in the test solution, wherein the content of furosine in the test solution is taken as an evaluation index of the protein powder freshness. The method based on innovative combination of earlier stage treatment in a chemical method and reversed phase ion-pair chromatography is utilized to determine the content of furosine in protein powder. The method for determining the product quality and the freshness of the protein powder has the characteristics of accuracy, rapidness, simplicity and good repeatability. Thus, the method is suitable for quantitative analysis of furosine in the protein powder and can also be used for judging the freshness and the quality of the protein powder.

The invention discloses a method for detecting the leonurine hydrochloride content in a nephritis elimination tablet. The detection method adopts a reversed phase ion pair chromatography method to measure the leonurine hydrochloride content in a nephritis elimination tablet, wherein the chromatographic condition adopts a C18 column, the mobile phase is acetonitrile-0.1% phosphoric acid solution of 0.2-0.6% sodium 1-octanesulfonate, and the detection wavelength is 260 to 290 nm. The detection method has the advantages of convenient operation, high sensitivity, and good repeatability, and provides a reference for establishment of quality standards for the nephritis elimination tablet.

The invention discloses a high performance liquid chromatographic method for detecting the mass concentration of sodium sulfocyanate in milk and a dairy product. The method comprises the following steps: adding acetonitrile in the a milk or dairy product sample, precipitating to remove protein from the milk or dairy product sample, removing part of water-soluble vitamin and amino-acid with a solid phase extraction column, collecting an eluent, and conducting centrifugal degrease on the eluent to obtain a semi-product for standby use; determining chromatographic conditions as follows: a chromatographic column is an Agela-ASB C18 chromatographic column, column temperature is 25 to 30 DEG C, flow velocity is controlled to be 0.8 mL / min, detection wavelength is 200 to 218 nm, and the sampling quantity is 8 to 10 [mu]m. The high performance liquid chromatographic method is based on a reversed-phase ion-pair chromatographic method, and is simple in pretreatment, high in detection sensitivity, good in accuracy, stable in result, and wide in popularization.

The invention provides a method for quickly detecting a heparin disaccharide content in heparin and / or low-molecular heparin. The method comprises S1) mixing heparin and / or low-molecular heparin solution with heparinase to react to obtain an enzymolysis product; S2) utilizing reversed-phase ion pair chromatography to detect the enzymolysis product and recording an HPLC spectrogram, wherein a mobile phase of the reversed-phase ion pair chromatography includes a mobile phase A and a mobile phase B, the mobile phase A is an organic solvent and water mixed solution containing reversed-phase ion pairs, the mobile phase B is an organic solvent and water mixed solution containing reversed-phase ion pairs and alkali metal chlorine salt, and the reversed-phase ion pairs are quaternary ammonium salt. Compared with the prior art, the method disclosed by the invention can obtain main heparin disaccharide composition and / or small fragments like trisaccharide and tetrasaccharide units by completelydegrading the heparin and / or the low-molecular heparin through the heparinase; a reversed-phased ion pair reagent and a reversed-phase chromatography are combined to quickly separate and quantitatively analyze the main heparin disaccharide composition and the small fragments; furthermore, the method has very good durability and repeatability.

The invention relates to a method for testing or analyzing a material by determining the chemical or physical properties of the material, in particular to a method for determining the contents of paraquat and diquat in biological fluid. The method comprises the steps: taking a fluid sample and sequentially adding a Triton X-114 aqueous solution, a NaCl aqueous solution and formic acid, so that thefinal concentration of Triton X-114 is 0.0545 to 0.109g / mL, the final concentration of NaCl is 0.0165 to 0.0495g / mL, and the final concentration of formic acid is 15 to 30 muL / mL; then oscillating, ultrasonically treating in a water bath, centrifuging, taking a supernatant, and filtering to obtain a sample injection solution of a sample to be determined; taking standard solutions of different concentrations of the same volume with the fluid sample to prepare a series of concentration standard product sample injection solutions; detecting the sample injection solution of the sample to be determined and a series of concentration standard product sample injection solutions by a liquid phase ion pair chromatography to obtain liquid phase chromatograms of the sample to be determined and standard products, the chromatograms thereof are compared to determine the characteristic peak, and then the content of paraquat or diquat in the sample is detected by calculation of a calibration curve according to the peak area.

The invention relates to a method for measuring alpha acid and beta acid in hops by an ion pair chromatography, which is characterized by comprising the following steps: a, preparing samples: preparing a hops tinctures sample by weighing a given weight of hops tinctures, diluting the hops tinctures with four to six times of chromatographic pure methanol in proportion by weight and filtering the diluted hops tinctures with 0.25 mu m of an organic phase filter membrane; preparing hops extractum by weighing a given weight of extraxtum, dissolving the hops extractum with 380-420 times of chromatographic pure methanol in proportion by weight and filtering the dissolved hops extrantum with 0.25 mu m of the filter membrane; and b, analyzing the prepared samples in step a by a diode-array detector of a liquid chromatogram. Compared with an original method for analyzing alpha acid and beta acid in hops, the method uses ion pair agent to avoid using strongly acid mobile phase, realizes better separation effect for alpha acid and beta acid than that of the current method, has good repeatability and recovery rate of experiments and is suitable for analysis of large quantities of samples.

The invention relates to the analysis technology field and especially relates to a method for analyzing a content of an imidacloprid synthetic intermediate through liquid chromatography-mass spectrometry. In the invention, a perfluorinated organic acid is taken as an ion-pairing agent. Under an ion-pairing chromatography condition, all the above intermediates can reach baseline separation and realize quantitative detection. Simultaneously, the ion-pairing agent is compatible with a mass spectrometry system and can be used for completing efficient separation and qualitative and quantitative detection in a liquid chromatography-mass spectrometry (LC / MS) system.

The invention provides a process for purifying a special reagent sodium dodecyl sulfonate for ion pair chromatography. The process is characterized in that the process concretely comprises the following steps: adding a raw material sodium dodecyl sulfonate to deionized water, carrying out ultrasonic irradiation oscillation, cooling the obtained solution to room temperature to precipitate crystals, and carrying out primary reduced pressure suction filtration, and collecting crystals; adding the obtained crystals to an ethanol-water mixed solution, carrying out heating refluxing stirring for 3-8h, cooling the obtained solution to room temperature to precipitate crystals, carrying out secondary reduced pressure suction filtration, and collecting the obtained filtrate; and carrying out constant low temperature crystallization of the obtained filtrate for 6-12h, carrying out third reduced pressure suction filtration, collecting crystals, and drying to obtain a special reagent sodium dodecyl sulfonate for ion pair chromatography. The purifying process has the advantages of novelty, simple operation, fastness, high efficiency, recycle of an organic solvent, economy, environmental protection, and suitableness for the industrialized production.

The invention discloses a detection technology for simultaneously analyzing betaine hydrochloride and methyl chloroacetate quaternary ammonium salt in a betaine hydrochloride synthesis reaction liquid. Ion pair chromatography is adopted for separation; an ultraviolet detector is used for detection; a single-point external standard method is used for determining the content of the betaine hydrochloride and the methyl chloroacetate quaternary ammonium salt; and a quality control method is provided for controlling the reaction process of a betaine hydrochloride synthesis process.

The present invention relates to a method for detecting or quantifying CTP in a cell sample comprising at least two nucleotide triphosphates by cationic ion pairing chromatography coupled to mass spectrometry, to a method for detecting or quantifying CTP synthase activity based on the method for detecting or quantifying CTP, and to their use in methods for screening potential immunosuppressive or anti-cancer compounds and in methods for determining the appropriate dose of an immunosuppressive or anti-cancer compound inhibiting CTP synthase activity for a treated subject.

The invention relates to a method for detecting the content of 3-amino-2-piperidone, in particular to a method for detecting the content of 3-amino-2-piperidone in a compound amino acid injection. According to the invention, the content of 3-amino-2-piperidone in the compound amino acid injection is detected by high performance liquid chromatography; chromatographic conditions overcome the defectsthat a C18 chromatographic column is weak in retention and an amino column and an HILIC chromatographic column are difficult to balance, ion pair chromatography is poor in reproducibility and the like. The method has the advantages of fast chromatographic column balance, extremely good specificity, high sensitivity, good accuracy, good reproducibility, low quantification limit and the like, the method is simple to operate and fast in analysis, the diluted sample is directly separated and analyzed on line by using the strong cation exchange chromatographic column, and the method is simpler andfaster compared with a traditional method for manually treating the sample by using cation exchange resin. The detection method can be used for qualitative or quantitative analysis of 3-amino-2-piperidone in other amino acid products or ornithine hydrochloride, arginine and other bulk drugs.

The invention relates to a preparation and purification method of ion-pair chromatographic reagent sodium pentanesulfonate. The specific steps of the preparation and purification method are: into a reaction vessel, the molar ratio is 1:25:0.65:(0.004~0.006) Add anhydrous sodium sulfite, water, pentane bromide, and tetrapropylammonium bromide in sequence, heat and reflux until the reaction liquid is clear and not stratified; evaporate the water in the reaction liquid under reduced pressure, dry the remaining solid, crush it, and put it into Extract in a Soxhlet extractor, then recrystallize the crude sodium pentanesulfonate obtained from the extraction, filter to obtain the pure product, and then dry it in vacuum to obtain the finished product. In the invention, anhydrous sodium sulfite and bromopentane are subjected to sulfonation reaction under the action of catalyst tetrapropylammonium bromide, and then purified and dried to generate high-quality sodium pentanesulfonate. The method is simple and easy to implement, low in cost and short in reaction time, and the generated sodium pentanesulfonate has good solubility, high purity, product content ≥ 99.6%, stable and reliable quality, and can fully meet the special requirements of high-performance liquid chromatography.

The present invention relates to testing or analyzing materials by means of measuring the chemical or physical properties of materials, in particular to a method for measuring the content of melamine in dairy products, the method comprising the following steps: taking dairy products, adding Triton X-114 aqueous solution, NaCl aqueous solution and formic acid, so that the final concentration of Triton X-114 is 30-50 μL / mL, the final concentration of NaCl is 0.4-1.2 mg / mL, and the final concentration of formic acid is 2.0-8.0 μL / mL; shaking, 40 ° C constant temperature water bath, Centrifuge, take the supernatant, filter to obtain the sample injection solution of the sample to be tested; configure the melamine standard stock solution, dilute the stock solution with a formic acid aqueous solution with a volume concentration of 0.6%, and obtain a series of concentration standard sample injection solutions; The sample injection solution of the sample to be tested and a series of concentration standard sample injection solutions are detected by liquid phase ion pair chromatography, and the liquid chromatograms of the sample to be tested and the standard are obtained, and then the two spectra are compared to determine the characteristics Peak, then calculate the content of melamine in the detection sample with the accompanying standard curve according to the peak area.

The invention relates to a method for measuring alpha acid and beta acid in hops by an ion pair chromatography, which is characterized by comprising the following steps: a, preparing samples: preparing a hops tinctures sample by weighing a given weight of hops tinctures, diluting the hops tinctures with four to six times of chromatographic pure methanol in proportion by weight and filtering the diluted hops tinctures with 0.25 mu m of an organic phase filter membrane; preparing hops extractum by weighing a given weight of extraxtum, dissolving the hops extractum with 380-420 times of chromatographic pure methanol in proportion by weight and filtering the dissolved hops extrantum with 0.25 mu m of the filter membrane; and b, analyzing the prepared samples in step a by a diode-array detector of a liquid chromatogram. Compared with an original method for analyzing alpha acid and beta acid in hops, the method uses ion pair agent to avoid using strongly acid mobile phase, realizes better separation effect for alpha acid and beta acid than that of the current method, has good repeatability and recovery rate of experiments and is suitable for analysis of large quantities of samples.

The invention provides a process for purifying a special reagent sodium dodecyl sulfonate for ion pair chromatography. The process is characterized in that the process concretely comprises the following steps: adding a raw material sodium dodecyl sulfonate to deionized water, carrying out ultrasonic irradiation oscillation, cooling the obtained solution to room temperature to precipitate crystals, and carrying out primary reduced pressure suction filtration, and collecting crystals; adding the obtained crystals to an ethanol-water mixed solution, carrying out heating refluxing stirring for 3-8h, cooling the obtained solution to room temperature to precipitate crystals, carrying out secondary reduced pressure suction filtration, and collecting the obtained filtrate; and carrying out constant low temperature crystallization of the obtained filtrate for 6-12h, carrying out third reduced pressure suction filtration, collecting crystals, and drying to obtain a special reagent sodium dodecyl sulfonate for ion pair chromatography. The purifying process has the advantages of novelty, simple operation, fastness, high efficiency, recycle of an organic solvent, economy, environmental protection, and suitableness for the industrialized production.

The invention discloses a method for determining related substances in 6-bromohexyltrimethyl ammonium bromide by ion pair chromatography, which comprises the following steps: (1) preparation of standard solutions: weighing standard substances of 6-bromohexyltrimethyl ammonium bromide and hexamethylamine bromide, respectively dissolving the standard substances with ultrapure water to a certain volume, and uniformly shaking the solution to obtain the standard substance solutions of the standard substances of the two components; (2) preparation of a sample solution: weighing a 6-bromohexyltrimethyl ammonium bromide sample, dissolving the sample with ultrapure water to a certain volume, and uniformly shaking the liquid to obtain the sample solution; (3) determination of a standard substance and a sample solution: carrying out sample introduction analysis on the standard substance and the sample solution by using an ion chromatograph according to certain chromatographic conditions, and recording peak areas at the same time; and (4) calculating the content of the substance to be detected: calculating the content of 6-bromohexyltrimethyl ammonium bromide and hexamethylamine bromide according to an external standard method. Compared with mass spectrometry, the method has the advantages that the test cost is low, complicated pretreatment is avoided, a 6-bromohexyltrimethylammonium bromide sample can be directly injected and analyzed after being dissolved by adding water, and the method is simple and easy to implement.

The invention discloses a compound represented by the formula (I) and having a purity of more than 99%. The high-purity medicinal compound is obtained by the following method: (1) carrying out primary purification on a crude product of the compound represented by the formula (I) by ion pair chromatography with reversed-phase high performance liquid chromatography (RP-HPLC), and carrying out gradient elution with a mobile phase; (2) after primary purification, carrying out pre-desalination treatment, and carrying out gradient elution with a mobile phase; (3) after completion of pre-desalination treatment, swashing an ion exchange column by a mobile phase to achieve the purpose of balance; and (4) carrying out ion exchange by ion exchange chromatography, carrying out secondary purification, removing remaining heptane sulfonic acid, and thus obtaining the pure compound represented by the formula (I).

A temozolomide suppository content measuring method by utilization of a reversed-phase ion-pair chromatography method is disclosed. The measuring method is characterized by comprising: (1) a step of preparing a reference substance solution; (2) a step of preparing a solution of a sample to be measured; and (3) a step of content measuring, namely a step of drawing 10-20 [mu]L of the reference substance solution and 10-20 [mu]L of the solution of the sample to be measured separately, injecting into a high performance liquid chromatograph, recording chromatograms, and calculating the content of the temozolomide in the sample to be measured according to the peak area in the chromatograms.