57 results about "Liquid-liquid chromatography" patented technology

A solvent delivery subsystem for a chromatography device performs relatively low pressure, high flow mixing of solvents to form a gradient and subsequent high pressure, low flow delivery of the gradient to the separation column. The mixing of the gradient is independent and does not interfere with the gradient delivery. To form the gradient, the outputs of an aqueous pump and an organic pump are mixed to fill a storage capillary while a downstream point from the storage capillary is vented to atmosphere. After gradient formation, the vent to atmosphere is closed, the solvent delivery system rises to high pressure, and only the aqueous pump runs for gradient delivery. To maintain integrity of the fluid stream, the solvent delivery system uses feed forward compensation and controls at least one parameter selected from the group consisting of pressure and flow in the conduit means to follow a gradual ramp.

The embodiment of the invention provides a method for detecting 25(hydroxyl)vitamin D by using a high-pass liquid chromatography-tandem mass spectrometry. The method comprises the following steps of: adding an acetonitrile solution containing an internal standard substance of the 25(hydroxyl)vitamin D into a human serum sample to carry out protein precipitation; sufficiently and uniformly mixing the solution, and then, adding an n-hexane extracting solvent; sufficiently and uniformly mixing the solution, then centrifuging the solution, movably taking a supernatant and drying the supernatant, and adding a complex solution to obtain a sample to be detected; detecting the sample to be detected by using a high-pass liquid chromatography-tandem quadrupole mass spectrometer; and quantifying according to the relative retention time of 25(hydroxyl)vitamin D2 and / or 25(hydroxyl)vitamin D3 and the detected abundance ratio of quantitative ion pairs by using an internal standard curve method. According to the embodiment of the invention, the method has the advantages of simplicity in pretreatment, strong specificity and matrix interference resistance, short detection time, high pass, high detection precision and low cost.

A method for separating and analyzing volatile and semi-volatile flavor components in tobacco by using liquid chromatography-gas chromatography / mass spectrometry technology comprises the following steps: 1. taking a given weight of tobacco products and extracting the volatile and semi-volatile flavor components from the tobacco by simultaneously adopting distillation and extraction; 2. concentrating the extracted samples with a concentrator; 3. carrying out group component separation on the concentrated extracted samples by normal-phase liquid chromatography and collecting distillates by different time sections; and 4. concentrating the collected distillates by the concentrator and respectively entering a gas chromatography-mass spectrometer (GC-MS) for detailed analysis. Compared with theprior art, the method of the invention can effectively extract the volatile and semi-volatile flavor components from the tobacco, carry out group component separation on the extract liquor by normal-phase liquid chromatography, then carry out accurate GC-MS qualitative and quantitative analysis on each group component according to different boiling points, not only has good selectivity and high separation efficiency but also ensures more accurate qualitative and quantitative analysis of each component.

The present invention relates to liquid phase chromatography-tandem mass spectrometry process for detecting specific tobacco fume nitrosamine content. The detection process includes: trapping tobacco fume with filtering sheet, adding internal standard substances, vibration extracting the filtering sheet with citric acid-phosphate buffering solution and cyclohexane, concentrating the organic phase extracted liquid in N2 protection, acidifying with hydrochloric acid, phase separating, neutralizing water phase with alkali solution, transferring the water phase solution into reverse chemical bonded solid phase extracting column, leaching with polar organic solvent aqua, eluting with polar organic solvent aqua, concentrating elutent, and analyzing in LC / MS / MS instrument quantitatively based on the area ratio between the component peak and the internal standard substance peak. The present invention has high repeatability, high recovering rate and low detection limit.

The invention provides an interface device for on-line coupling of LC-GC / MS and a method for analyzing fragrant components in tobaccos by utilizing the device. According to the method, reverse blowing gas can be provided through switch of a gas switch valve, during sample injection, the reverse blowing gas is discharged form a GC flow-splitting port against the GC carrier gas direction through a tee coupling, therefore solvents can be transferred out completely, solutes are reserved in a TenaxTA absorbent in a PTV liner tube, thermal desorption is performed on a PTV injection port after the solvents are transferred completely, the GC carrier gas shifts cut fractions to be tested into a GC column for separation, effects on an MS vacuum system due to the fact the solvents enter the GC column are effectively avoided, and large volume injection can be achieved.

The invention discloses a method for reducing flow fluctuations in a liquid chromatograph and an infusion pump device. The infusion pump device comprises a main control unit, the main control unit in control connection with a motor, the motor is in transmission connection with a cam group, and the cam group comprises a large cam and a small cam, wherein the large cam and the small cam are connected in series. The large cam and the small cam are respectively provided with a cam positioning device and drive a first plunger rod and a second plunger rod to alternately reciprocate in a first hydraulic cylinder and a second hydraulic cylinder respectively. An inlet in the first hydraulic cylinder and an outlet in the first hydraulic cylinder are respectively provided with a one-way valve, and the outlet in the first hydraulic cylinder is connected with the second hydraulic cylinder and provided with a pressure detecting device for detecting the pressure of a flowing phase in a monitoring system in real time. The cam positioning devices and the pressure detecting device are connected with the main control unit, the pressure detecting device is further connected with one input end of a comparator, and the other input end of the comparator and the output end of the comparator are both connected with the main control unit. The method for reducing the flow fluctuations in the liquid chromatograph and the infusion pump device ensure that analysis results of the liquid chromatograph are accurate and reliable.

Wherein, adding a new six-way valve (3), coupling a solid-phase extraction column (4) contained replaceable absorbent, a high-pressure transfer pump (2), and a set of industrial high-effect liquid chromatograph with self-carried liquid phase six-way valve (7) by a stainless steel tube. This invention is fast and high-effective, and has wide application for drinking water, surface water, etc.

An ultrahigh-pressure dual on-line solid phase extraction / capillary reverse-phase liquid chromatography (DO-SPE / cRPLC) system is provided. The system comprises: a sample loading valve into which a first solvent and a sample to be analyzed are loaded; a first column valve in flow communication with a first solid-phase extraction column and a first reverse-phase liquid chromatography column; a second column valve in flow communication with a second solid-phase extraction column and a second reverse-phase liquid chromatography column; a column-switching valve for determining whether the sample is transferred to either the first column valve or the second column valve; a solvent selection valve in flow communication with the first and second column valves to supply the first solvent or a mixed solvent of the first solvent and a second solvent to the first and second column valves; a second solvent loading valve, in flow communication with a solvent mixer, into which the first and second solvents are loaded; a supply pump for loading the second solvent into the second solvent loading valve; and a supply pump for loading the first solvent into the sample loading valve, the second solvent loading valve and the solvent selection valve. The system requires minimal time (i.e. dead time) for column equilibration between successive experiments to shorten the total time required for the experiments by a factor of about two. In addition, the system enables rapid sample injection, on-line sample desalting and sample enrichment. Furthermore, the system is highly reproducible in terms of liquid chromatography (LC) retention time and can be operated at a pressure as high as 10,000 psi.

The invention relates to a method for detecting the cationic surfactants of alkyl quaternary ammonium salts with the liquid chromatography-tandem mass spectrometry and includes the following steps: pre-treating the detected samples with a Soxhlet extraction method or a supersonic extraction method; detecting with a liquid chromatograph-tandem mass spectrometer with the LC conditions of a C18 reverse-phase chromatographic column, a column temperature of 30 to 60 DEG C, the inlet volume of 3 to 10ul, the mobile phase flow rate of 0.15 to 0.60ml per minute; the tandem mass spectrometry MS / MS is provided with the conditions of ionizing by adopting the electro-spray ionization model and the detection mode of multi-ion reaction. The method adopted by the invention is characterized by accurate and fast analysis method, high method selectivity, little interference, etc.

Polymer fibers having a novel cross-sectional geometry are used as stationary phase materials for liquid chromatography separations. Fibers of 20 to 50 micrometer diameters have surface-channel structures extending their entire lengths. Bundles of fibers having this novel cross-sectional geometry are packed in columns. Different polymer compositions permit the “chemical tuning” of the separation process. Channeled fibers composed of polystyrene and polypropylene have been used to separate mixtures of polyaromatic hydrocarbons (PAHs), Pb-containing compounds and fatty acids. Use of channeled fibers allows a wide range of liquid flow rates with very low backing pressures. Applications in HPLC, cap-LC, prep-scale separations, analytical separations, single fiber separations, waste remediation / immobilization, extraction of selected organic molecules / ions from solution, purification of liquid streams (process waste, drinking water, pure solvents), selective extraction of cell matter and bacteria from growth media, and immobilization of cell matter and bacteria are envisioned.

The invention relates to a method for simultaneously detecting trichlorfon and moncrotophos through molecularly imprinted solid phase extraction and liquid chromatography. A high-adsorption-performance molecularly imprinted polymer MIL@MIP is prepared; a hollow molecularly imprinted solid phase extraction column is filled with the high-adsorption-performance molecularly imprinted polymer MIL@MIP, and liquid chromatogram is introduced for analysis; the concentration of a trichlorfon solution and the concentration of a moncrotophos solution serve as the horizontal coordinates respectively, the area of a chromatographic peak serves as the longitudinal coordinate, and a trichlorfon standard curve and a moncrotophos standard curve are drawn respectively; the content of trichlorfon and the content of moncrotophos in an analyte are calculated according to the drawn standard curves. A novel metal framework material MIL-101 with porosity and a large specific surface area serves as a support carrier, and adsorption performance of the prepared polymer is greatly improved; besides, the metal framework material has high selectivity to both trichlorfon and moncrotophos and can take the place of a single polymer to be used in solid-phase extraction; the prepared molecularly imprinted polymer prepared through the method can be repeatedly used for about 20 times, and cost is greatly reduced.

The invention discloses a method for simultaneously detecting nine types of oestrogen substances in water by solid phase extraction-liquid chromatography-tandem mass spectrometry. The method comprises(1) carrying out water sample pretreatment, (2) enriching and purifying a target oestrogen with a solid phase extraction small column and (3) quantificationally detecting nine types of oestrogen substances in water through an internal standard method through a high efficiency liquid chromatography-tandem mass spectrometer. The method utilizes a single factor test, optimizes the type of a solid phase extraction small column, pH in solid phase extraction, the type and use amount of an eluting agent and the type and use amount of an eluent, optimizes a liquid chromatographic column temperature,a flowing rate, a sample loading amount, a flowing amount, the fluid type and a gradient ratio, has short peak production time and produces an ion chromatogram having a good separation degree. The method utilizes the internal standard substance indicating a recovery rate before solid phase extraction, well shows the loss of the target substances in the pretreatment and produces a real and reliablefinal result.

There is provided a method for thermally focusing the elution times of compounds of a liquid chromatography system comprising a pre-column and a separation column as well as to provide a liquid chromatography system, wherein the chromatographic separation of a mixture of substances is optimized.

A mass spectrometry method by a liquid chromatograph-mass spectrometer that can detect an organic acid with high sensitivity by retaining, separating and eluting the organic acid without adding any nonvolatile substance to a mobile phase and without receiving any restriction of a ratio of a water-soluble organic solvent, and an analytical column are provided. The mass spectrometry method is a mass spectrometry method for an organic acid by a liquid chromatograph-mass spectrometer, wherein a column packed with a hydrophilic polymer having an anion-exchange group is used, and as a mobile phase, a water-soluble organic solvent-water mixed solution is used. The analytical column is a column for liquid chromatography for an organic acid, in which a polyether ether ketone (PEEK) resin housing for liquid chromatography is packed with a hydrophilic polymer having an anion-exchange group.

The invention relates to a hollow-fiber membrane liquid-phase micro-extraction and liquid chromatography coupling device and a polysaccharide component on-line quantitative analysis method thereof. The device comprises a sample feeding part, a liquid chromatography pump, a six-way valve, a chromatographic column, a detector, a sample ring, a waste liquid bottle and an ultrasonic washer, wherein a hollow-fiber membrane liquid-phase micro-extraction device is arranged inside the ultrasonic washer; general liquid chromatography pipelines are arranged at two ends of the hollow-fiber membrane liquid-phase micro-extraction device; the general liquid chromatography pipeline at one end is connected to the six-way valve and the sample feeding; the six-way valve is respectively connected to the liquid chromatography pump, the chromatographic column, the sample ring and the waste liquid bottle; the chromatographic column is connected to the detector; the detector is connected to the waste liquid bottle. The hollow-fiber membrane liquid-phase micro-extraction and liquid chromatography coupling device has the characteristics as follows: samples are efficiently and quickly purified; the method is scientific and reasonable; the extraction conditions are adjustable; the application prospect is good.

The invention relates to a liquid chromatography-mass spectrometry combined analysis method and an interface device thereof. A mass spectrometer performs analysis and obtains an analysis map through the following steps: installing a solid probe; setting a shunt piece; installing a sample tube; turning on a liquid chromatography system and the mass spectrometer and applying a high voltage to the solid probe; then injecting a sample solution to perform an electrospray process; and adjusting a position of the solid probe to obtain a maximum signal of the mass spectrometer. According to the invention, the solid probe with a shunt piece is used as a liquid chromatography-mass spectrometry combined electrospray ion source interface, and most of the sample effluent of the liquid chromatography system is shunted along the shunt piece and only a small fraction is sprayed. The spray droplet produced by the invention has small diameter and high surface charge density; therefore, the signal intensity of the invention is higher than that of the conventional liquid chromatography-mass spectrometry combined system.

The present invention aims to provide a liquid chromatograph, an analysis system, and a gradient elution method, which are designed to permit a gradient change of eluent with higher precision and also permit a high sensitive detection or analysis. For attaining the object, there are provided: a liquid chromatograph having at least a liquid-feeding means for flowing an eluent E at a predetermined flow rate, a sample-pouring means for pouring a sample Sm into the eluent E, and a separation-column means for separating a solute So contained in the sample Sm into components, comprising an eluent-selecting means for forming branched flow paths having predetermined volumes by dividing a flow path of the eluent E fed from the liquid-feeding means, temporally storing eluents E1, E2, and soon in the branched flow paths, and pouring the sample Sm into the selected eluents E1, E2, and so on, and means for carrying out a gradient elution of a solute So; an analysis system comprising a mass spectrometer connected to the liquid chromatograph, and a gradient-elution method using the liquid chromatograph.

The invention relates to a chiral LC-MS (liquid chromatograph-mass spectrometer) / MS high-throughput detection method for pantoprazole in human plasma. The method includes the steps: taking plasma samples to be detected to mix into internal standard solution; adding 500muL internal standard solution into the plasma samples to serve as protein precipitators by the aid of a pretreatment method of a protein precipitation method; taking liquid supernatant after vortex and centrifugation to obtain samples to be detected; performing LC-MS analysis. The method has the advantages that the method meets analysis requirements of large-batch clinical samples and is simple to operate, short in pretreatment time and chromatographic analysis time and suitable for pretreatment of high-throughput samples as compared with the prior art.

The invention discloses a liquid chromatography-mass spectrometry screening method for a multi-target antithrombotic substance based on a dried blood spot sample, and belongs to the field of drug screening. The method comprises the following steps of preparing a rehydrated dry blood spot sample, optionally selecting a plurality of substrates of key target enzymes involved in thrombosis processes,mixing a plurality of substrate standard solutions with a substance to be screened, adding a mixture into the rehydrated dry blood spot sample, treating a reaction solution, and carrying out liquid chromatography-mass spectrometry analysis to screen to obtain a substance with multi-target antithrombotic activity. The screening method of the invention has the advantages of simplicity and rapidness,high accuracy, high specificity, a large number of samples can be continuously analyzed, the antithrombotic substance capable of inhibiting one or more target enzymes at the same time can be screenedout at the same time according to the screening method, action targets of the screened active substance are clear, and a theoretical basis is laid for subsequent drug development. Reagents are easy to obtain, the operation automation degree is high, clinical popularization and promotion are easy, and the commercial value is high.

A solvent delivery subsystem for a chromatography device performs relatively low pressure, high flow mixing of solvents to form a gradient and subsequent high pressure, low flow delivery of the gradient to the separation column. The mixing of the gradient is independent and does not interfere with the gradient delivery. To form the gradient, the outputs of an aqueous pump and an organic pump are mixed to fill a storage capillary while a downstream point from the storage capillary is vented to atmosphere. After gradient formation, the vent to atmosphere is closed, the solvent delivery system rises to high pressure, and only the aqueous pump runs for gradient delivery. To maintain integrity of the fluid stream, the solvent delivery system uses feed forward compensation and controls at least one parameter selected from the group consisting of pressure and flow in the conduit means to follow a gradual ramp.

The invention discloses a method for detecting cyanine in textile through reversed-phase high-efficiency liquid chromatography. The method comprises the following steps: (1) a solution of a sample to be detected is prepared; (2) a standard solution is prepared; (3) the standard solution is taken out, is injected to a high-efficiency liquid chromatographic instrument and is mensurated through a reversed-phase high-efficiency liquid chromatography method; the peak-out position of the cyanine is mensurated by a liquid chromatography-mass spectrometry instrument; the peak-out area is recorded; with concentration as an abscissa and the peak-out area as an ordinate, a standard curve equation is manufactured; and (4) according to the method in step (3), the cyanine and the peak-out area in the solution of the sample to be detected are mensurated; and the obtained standard curve is used to obtain the content of the cyanine in the sample to be detected through calculation. The method can accurately, reliably and sensitively mensurate the cyanine and the content of the cyanine in the textile.

The invention discloses a high performance liquid chromatography detection method for the abamectin content in edible vegetable oil. The method comprises the steps that a sample is subjected to vortex oscillation extraction through methanol, purified with an ODS C18 solid-phase extraction column, subjected to derivatization through N-methylimidazole and trifluoroacetic anhydride and lastly determined through a liquid chromatography-fluorescence method. According to the method, few reagents are adopted, and the cost is reduced; a sample pretreatment method is simple, the purification effect is good, maintenance of instruments in the using process is reduced, and the technical problems that when a liquid chromatography-ultraviolet detector is used, the sensitivity is too low, and matrix interference is serious are solved; a determined result is accurate and good in repeatability, the detection specificity and sensitivity are high, and a reference is provided for detection of the abamectin content in the edible vegetable oil.

The invention provides a liquid phase mobility separating device, a control method, and an interface used for liquid chromatography-mass spectrometry. The liquid phase mobility separating device comprises a separation capillary, a syringe pump, a sample introduction needle, a separation electrode, and a grounding electrode; one end of the separation capillary is provided with an electrospray point, and the other end is provided with a buffer injection point; the syringe pump is connected with the buffer injection point; the sample introduction needle is connected with the separation capillaryat a position close to the syringe pump; the separation electrode is connected with the syringe pump, or is connected with the separation capillary at a position close to the syringe pump; the grounding electrode is connected with the separation capillary at a position close to the electrospray point. The liquid phase mobility separating device is capable of realizing component separation of a complex sample system, and improving separation effect.

A liquid leakage decision unit includes a leak sensor value storage part that stores a leak sensor value that is based on the intensity of a signal received from a gas sensor; a difference calculation part that, when the signal is received from the gas sensor, calculates, as a difference value, a value obtained by subtracting a previous leak sensor value stored in the leak sensor value storage part from a current leak sensor value; and a liquid leakage detection part that compares the difference value calculated by the difference calculation part with a preset threshold, thereby to detect liquid leakage in the column oven.

The invention relates to a detecting method for the organic acid and ester in centrifugal waste water in the cis-butenedioic anhydride production process through liquid chromatography, the method uses Agilent C18 chromatographic column as the analytical column, water, methanol, and acetidin are mixed in a certain proportion as mobile phase, the flow velocity is 1.0mL / min, the column temperature is 40 DEG C, the operating time is 25min, the sample volume is 20muL, an external standard method quantificationally analyzes the organic acid and ester in the cis-butenedioic anhydride waste water through liquid chromatography, the linearly dependent coefficient is more than 0.9969. The invention carries out the effective quantitative analysis for the organic acid and ester in centrifugal waste water in the cis-butenedioic anhydride production process, the detecting method is simple and has good reproducibility; the detecting result is accuracy, the sensitivity is high, which acts a positive pushing effect for enhancing the product quality and lowing product cost of the cis-butenedioic anhydride.

The invention relates to the manufacture of an interface used for the combination of a liquid chromatographic separation system and a mass spectrum, in particular to a manufacturing device of a capillary spray interface used for the combination of liquid chromatogram and the mass spectrum, which comprises a 'U'-shaped bracket, two top ends of the 'U'-shaped bracket are respectively provided with a coaxial transverse sliding chute, hollow adjusting screw rods are respectively arranged in the sliding chutes and can transversely slide along the horizontal direction in the sliding chutes; the inner and outer surfaces of the inner side of the adjusting screw rod are respectively provided with internal screw threads and external screw threads, a PEEK head is screwed on the front end of the adjusting screw rod through the internal screw threads and internally passed by a polytetrafluoroethylene tube or a PEEK tube, an adjusting screw nut is arranged on the external screw threads; the interior of the 'U'-shaped bracket is provided with a high-temperature flame lamp; wherein, the inner chamber of the polytetrafluoroethylene tube or the PEEK tube is used for being sheathed with a quartz capillary. The device has simple manufacturing technology, uses raw materials with low price, and can comparatively and conveniently manufacture ideal mass spectrum spray interfaces with high mission success rate and good uniformity.

Embodiments of the present invention feature methods and apparatus for performing chromatographic separations. The invention feature methods and control means in the form of computer programs and software that control the formation of a concentration gradient at two or more total flow rates, with an elution period occurring in a slow flow rate and at least other portions of the gradient occurring during a fast total flow rate.

The invention provides a method for separating and determining methyhaaltrexone bromide and impurities and contents thereof with liquid chromatography. The method comprises the following steps: (a) adopting a chromatographic column using alkyl-silicane bonded silica gels as packing to be a separation column; (b) using a trifluoroacetic acid buffer solution as a flowing phase A, and using an organic solvent as a flowing phase B; and (c) and adopting gradient elution for the flowing phases, and separating and determining the impurities and contents of methyhaaltrexone bromide and a preparation thereof. According to the method, methyhaaltrexone and other known intermediate impurities as well as unknown impurities can be effectively separated and determined. The method has strong specificity, high accuracy and convenience for operation.

The invention discloses a pre-column derivatization device of a liquid chromatography and an ion chromatography. The pre-column derivatization device comprises a liquid-phase solution, a pump, a reaction device, a sample feeder, a heat-preservation box chromatographic column and a detector, which are connected in sequence, as well as a stirring device, wherein the reaction device comprises a shell, a reaction chamber and a temperature control unit; the reaction chamber is arranged in the shell; one end of the reaction chamber is communicated with the pump and the other end of the reaction chamber is communicated with the sample feeder; a heat-preservation layer is arranged on an outer wall of the reaction chamber; the temperature control unit comprises a temprature control panel and a temperature control circuit board; a groove for storing the temprature control panel is formed in the bottom end face of the reaction chamber; the temprature control panel is fixed in the groove and is used for controlling temperatures of the reaction chamber; the stirring device comprises a motor and fan blades; the motor is arranged outside the reaction chamber and the fan blades are arranged in the reaction chamber; an output shaft of the motor convexly stretches into the reaction chamber and is connected with the fan blades; and the stirring device is used for sufficiently mixing reaction solutions. The pre-column derivatization device provided by the invention has high temperature and reaction time control properties and high derivatization efficiency.