51 results about "Syringe filter" patented technology

Devices and methods are provided for reducing matrix effects in protein precipitated bioanalytical samples comprising: a support, and a sorbent associated with the support capable of binding matrix interfering agents present in the bioanalytical sample, wherein the device further comprises filtering means for removing precipitated protein particles. The filtering means is a size exclusion filter or a polymeric or inorganic monolith having a maximum pore size less than or equal to the diameter of the particles to be removed from the sample, and can be integral with the sorbent or associated with the sorbent. The sorbent is characterized by sufficient selectivity between the matrix interfering agents and analytes of interest to provide retention of the matrix interfering agents while providing elution of the analytes of interest (e.g., a reversed phase or a polar modified reversed phase). Typical devices incorporating these features include luer syringe filters, individual filter cartridges, multiwell plates, pipette tips, or inline columns for multiple or single use.

The invention discloses a fluorescent carbon quantum dot with magnolia alba leaf blades as a carbon source and a preparation method of the fluorescent carbon quantum dot. The yield of fluorescent quantum is 8.3 to 13.8 percent. The preparation method comprises the following steps: dissolving 0.50 to 2.00g of magnolia alba leaf blade powder into 30mL of deionized water and enabling the concentration of the magnolia alba leaf blade powder to be 0.017 to 0.067g/mL; carrying out ultrasonic concussion for 10 to 40 minutes; then reacting at the temperature of 140 to 220 DEG C for 4 to 24 hours by adopting a hydrothermal method to obtain a fluorescent carbon quantum dot solution; carrying out ultrasonic concussion on the fluorescent carbon quantum dot solution for 10 to 40 minutes, and carrying out supercentrifugation at the speed of 4000 to 16000r/min for 10 to 40 minutes; then filtering by using an aqueous phase needle cylinder type filter, and taking supernate to obtain the fluorescent carbon quantum dot solution. The fluorescent carbon quantum dot disclosed by the invention has the advantages of high fluorescence quantum yield, simple preparation, low toxicity, good biocompatibility and water solubility and small particle size.

A syringe and filter cap ease the administration of medication to patients. The cap fits securely over the syringe nozzle and has at least one orifice. The orifice is configured to retain medication particles within the syringe, while allowing liquid to be drawn into the syringe through the cap. A kit combines the medication, the syringe and its plunger, the cap, and a liquid holder cup. The method of administering the medication entails: (a) removing the plunger from the syringe, (b) placing the cap over the nozzle, (c) inserting the particulate medication into the syringe, (d) re-inserting the plunger into the syringe, (e) drawing the desired amount of liquid into the syringe through the cap, thereby suspending the particulate medication within the liquid drawn into the syringe, (f) removing the cap from the syringe, and (g) delivering the medication dosage to the patient.

The invention relates to a sulfydryl-amidogen modified bifunctional mesoporous silicon material synthesized by a copolycondensation method. The material can simultaneously adsorb two types of inorganic arsenic forms, namely pentavalent arsenic (As (V)) and trivalent arsenic (As (III)) under the condition of weak acid. The prepared material is put in a syringe filter and is fixed by virtue of a filter membrane so as to be made into a simple solid-phase extraction head. When solid-phase extraction is carried out, a sample solution passes through the extraction head, and the two types of inorganic arsenics in the solution are adsorbed by the material at the time; then a strategy of stage elution is adopted: the adsorbed As (V) is eluted with dilute nitric acid and collected to determine, then the adsorbed As (III) is eluted with a nitric acid/potassium iodate solution and collected to be measured, and therefore the contents of As (V) and As (III) in the sample solution are obtained. Compared with other solid-phase extraction methods, the method has the advantage that the sample only needs once extraction so that the contents of As (V) and As (III) can be respectively obtained. In addition, a device is simple and convenient, and the sample pretreatment is easily and fast completed.

The invention relates to an antibiotic detection method. The method concretely comprises the following steps: (1) carrying out pretreatment for vegetable samples in order to obtain an antibiotic extract; (2) carrying out extraction for the antibiotic extract in order to obtain an antibiotic eluate; (3) evaporating the antibiotic eluate to dryness by a rotary evaporator, carrying out volumetric flask preparation with an initial mobile phase, and carrying out filtering with a syringe filter in order to obtain an antibiotic liquid to be measured; (4) carrying out detection for the antibiotic liquid to be measured by optimized high performance liquid chromatography-tandem mass spectrometry in order to detect antibiotics to be measured. The method for detecting 11 kinds of antibiotic residues in vegetable samples has the advantages of high recovery rate and low detection limit, and overcomes the disadvantages and insufficient that antibiotic detection methods in the prior art have high cost, few antibiotic detection kinds, and high detection limit; a base for assessing antibiotic environmental behaviors and risks is established.

The invention discloses a microfluidic syringe filter head and a use method thereof. The filter head uses a microfluidic technology to concentrate and enrich micro-particles or cells, wherein a spirally extending micro-flow channel and a Y-shaped forked flow channel communicated with the micro-flow channel are formed inside the filter head; micro-particles of sample liquid are subjected to dragging force in a flowing direction, and are also subjected to inertial lifting force and Dean dragging force perpendicular to a main flowing direction in the micro-flow channel; under coupling action of the two transverse forces, the micro-particles may be gradually focused to a wall surface on one side close to a spiral center to form a regular arrangement bundle and flow out along a branch inside the Y-shaped forked flow channel so as to collect the concentrated sample liquid. The micro-flow channel and the Y-shaped forked flow channel in the invention are arranged on the same plane so as to effectively reduce a volume occupied by the flow channels and benefit to miniaturization of the filter head; the filter head is simple in use method and suitable for use in the field and low-hardware configuration laboratory environments.

The invention provides a method for determining the specific migration quantity of nine kinds of antioxidants in a plastic product through a liquid chromatography-mass spectrometry method. Through the method, the specific total migration quantity of nine kinds of antioxidants in five kinds of food simulants can be determined. The method includes the steps that a sample to be measured is soaked in the food simulants, the sample to be measured and the food simulants are cooled to room temperature and evenly mixed, and after the food simulants are diluted and filtered through a hydrophilic teflon syringe filter, sample introduction is performed; after the olive oil food simulants are extracted through methanol n-heptane and filtered through the hydrophilic teflon syringe filter, sample introduction is performed; gradient elution separation is performed through a C8 column; an electrospray ionization source is adopted for mass spectrometry and operates in a negative ion multi-reaction monitoring mode. According to the method, chromatographic separation and a linear relation are good, the recovery rate and the accuracy are high, the limit of quantitation meets limit requirements of nine kinds of antioxidants in the EU NO 10/2011 regulation, and the method has been applied to detecting practical samples.

The invention discloses plant-source environment-friendly fluorescent carbon quantum dots as well as a preparation method and application of the plant-source environment-friendly fluorescent carbon quantum dots. The preparation method comprises the following steps: mixing deionized water with rosa sterilis according to a mass ratio of 0.5 to 3 to obtain a mixture; adding the mixture into a stirring machine to be fully ground to obtain homogenate; weighing 20.0 to 70.0g of homogenate; putting the homogenate into an inner tank of a 100ml reaction kettle for performing ultrasonic oscillation for5 to 20 minutes to ensure that substances in the homogenate are fully dispersed; performing reaction for 8 to 24 hours at 140 to 220 DEG C by adopting a hydrothermal method to obtain a primary carbonspot solution; performing ultracentrifugation on the primary carbon spot solution for 10 to 30 minutes at the speed of 12000 to 20000r/min; filtering supernatant liquid by adopting a syringe type filter to obtain a carbon spot solution. The plant-source environment-friendly fluorescent carbon quantum dots disclosed by the invention have the advantages that the average fluorescent service life is 4.36ns, the fluorescent quantum yield is 15.0 to 24.8 percent and the fluorescent quantum yield is high; preparation conditions are simple and environmentally friendly, plants are used as carbon sources, the biocompatibility is good and the plant-source environment-friendly fluorescent carbon quantum dots are low in toxicity.

The present invention provides a syringe for filtering a liquid comprising: a housing with a plunger slidable therein; an inlet for taking in liquid from a liquid source into the housing; an outlet for expelling liquid from the inside of the housing; a filter; and a rotatable valve member being rotatable between a first position and a second position; wherein rotation of the valve member to the first position permits liquid that is drawn through the inlet into the housing by pulling the plunger to bypass the filter, and rotation of the valve member to the second position forces liquid that is expelled from the inside of the housing by pushing the plunger to pass through the filter and out of the outlet.

The invention belongs to the technical field of food safety, and more specifically relates to a method used for detecting fruit pesticide residue. The method comprises following steps: step a, a sample to be detected is washed with clear water, and is cut into 4*4mm blocks; step b, 5 to 15g sample block is added into centrifugal tubes filled with anhydrous sodium acetate and anhydrous magnesium sulfate, an acetic acid acetonitrile solution is added, an obtained mixture is subjected to violent shaking, ultrasonic extraction, and centrifugation; step c, an acetonitrile extract obtained via centrifugation is delivered into centrifugal tubes filled with 2 to 5g of a cleaning agent, the centrifugal tubes are subjected to vibration using an oscillator for 5min, and are allowed to stand for 5min, a supernatant is collected, is delivered into a needle cylinder-type filter directly so as to remove suspended matters in the supernatant via filtering, and an obtained filtrate is collected in a test tube; step d, the test tube filled with the filtrate is subjected to water bath at 40DEG C, and the solvents in the test tube are removed completely via air purging, and an obtained mixed solution with an acetonitrile/water volume ratio of 1:1 is diluted to a constant volume for further detection; and step e, liquid chromatography is adopted for detection. The method is rapid, accurate, high in efficiency, and low in cost.

The invention relates to a cell membrane particle expressing parafusin and preparation and application of the particle. VSVG is expressed on the cell membrane particle. Biomacromolecules and organelles are wrapped in the cell membrane particle. The cell membrane particle does not have a cell nucleus. The preparation method includes the steps that transient transfection is conducted on Ad293 cells through expression vesicular stomatits virus protein plasmids; the cells are digested through pancreatic enzymes 48 hours after transfection is carried out, and then centrifugation is carried out for 3 min; an obtained cell suspension is placed in a syringe, the syringe is installed in a syringe filter provided with a polycarbonate membrane, the syringe is pushed so that the cell suspension can be pushed from one side of the filter to the other side of the filter, and the cell membrane particle expressing VSVG is obtained. The cell membrane particle expressing parafusin is applied to biomacromolecule and organelle transfer. The membrane particle is larger, can wrap biomacromolecules and mitochondria, and transfers protein and the mitochondria in the aspect of function. Extra chemical reagents are not added, activity of VSVG is effectively maintained, mitochondrion release efficiency of the membrane particle is improved after the membrane particle enters a body, and accordingly mitochondrion transfer efficiency is improved.

The invention discloses a syringe filter which comprises an upper cover, a lower cover, a filtering membrane and coating rings, wherein the upper cover comprises an upper cover plate body and an input tube part; the lower cover comprises a lower cover plate body and an output tube part; the upper cover plate body is connected and matched up and down with the lower cover plate body; the edges of the filtering membrane are clamped and fixed through the upper cover plate body and the lower cover plate body, so that a cavity is divided into an upper part and a lower part; peripheries of the upper cover plate body and the lower cover plate body are coated with the coating rings; a plurality of supporting rods A are arranged at the communication part of the tube hole of the input tube part and the cavity; the upper cover plate body is provided with a plurality of arc-shaped bulges A, circular arc-shaped grooves A and radial grooves A, which are formed in the inner wall of the cavity; a plurality of supporting rods B are arranged at the communication part of the tube hole of the output tube part and the cavity; the lower cover plate body is provided with a plurality of arc-shaped bulges B, circular arc-shaped grooves B and radial grooves B, which are formed in the inner wall of the cavity; a plurality of reinforcing ribs are arranged at the bottom of the lower cover plate body. By adopting technical scheme of the invention, the filtering membrane is less susceptible to damage, the filter is less susceptible to blockage, and the filtering speed is stable and high.

The invention discloses a liquid chromatographic detection method of polycyclic aromatic hydrocarbons in edible oil. The liquid chromatographic detection method comprises the following main steps: 1),extracting: weighing a proper amount of sample, putting into a clean centrifuge tube, dissolving the edible oil by using n-hexane saturated by acetonitrile, extracting the polycyclic aromatic hydrocarbons twice by using acetonitrile saturated by n-hexane, and transferring an acetonitrile layer to an eggplant-shaped bottle; 2), concentrating under reduced pressure: concentrating an extract under reduced pressure in a 40 DEG C water bath environment until the volume is about 2ml; 3), performing SPE purification: purifying an obtained concentrate by using an SPE column, and collecting an effluent in a graduated glass tube; 4), performing nitrogen blowing concentration: performing nitrogen blowing concentration on collected liquid at 40 DEG C until the volume is lower than 1ml; 5), fixing thevolume: fixing the volume by using acetonitrile until the volume is 1ml, filtering by using a syringe filter membrane with the thickness of 0.2 microns, and waiting for detection in a sample feedingbottle; 6), detecting and analyzing: analyzing and detecting an obtained solution to be detected by HPLC. By the liquid chromatographic detection method, the operation is simple and quick, the stability is good, the popularizing rate of detection equipment is high, and application is convenient.

The present invention relates to an eye drop composition for treating dry eye syndrome, characterized in that the eye drop composition remains stable during storage without precipitation occurring andcontains a safe ingredient for use as an eye drop, by solubilizing rebamipide that is a poorly soluble compound, and a method for producing the same. The eye drop composition for treating dry eye syndrome of the present invention includes a base for solubilizing rebamipide, and is characterized by containing a stabilizer for maintaining a supersaturated stabilized state, a specific type of bufferfor maintaining biocompatible pH of 7 to 8 and an osmotic agent. A method for producing the same comprises the steps of: adding a base to rebamipide or a pharmaceutically acceptable salt thereof anda stabilizer and dissolving the same in water to obtain an aqueous eye drop solution of pH of 10 to pH of 11; adding at least one osmotic agent selected from a buffer and a nonionic osmotic agent to the eye drop solution and dissolving the same; and after adjusting the pH to 7 to 8 with an acid, filtering the solution with a syringe filter to make the same sterile. The produced eye drop is in theform of an aqueous solution, is stable when frozen, refrigerated, and at room temperature, and includes a therapeutic agent for dry eye syndrome which is stable even when cross-stored in a refrigerator or at room temperature, or at a refrigerating temperature or room temperature.

A method for fractionating a liquid include contacting a liquid comprising at least one type of encapsulating particle with at least one mesoporous isoporous block copolymer material, wherein at least one component of the liquid is separated. A device for fractionating a liquid having encapsulating particles includes at least one mesoporous isoporous block copolymer material. The device can further include an inlet to allow the liquid to contact the mesoporous isoporous block copolymer material, and an outlet to allow passage of the fractionated liquid. In some instances, the device can be a pleated capsule, a flat sheet cassette, a spiral wound module, a hollow fiber module, a syringe filter, a microcentrifuge tube, a centrifuge tube, a spin column, a multiple well plate, a vacuum filter, a flat sheet, or a pipette tip.

The invention discloses a syringe filter and a lower cover thereof. The lower cover comprises a lower cover plate body and an output tube part arranged in the center of the lower cover plate body, wherein a plurality of supporting rods B are arranged at the connection part of the output tube part and the lower cover plate body; the supporting rods extend along the tube hole of the output tube part in the radial direction and are gathered and connected to the center of the tube hole; the lower cover plate body is provided with a plurality of arc-shaped bulges B, circular arc-shaped grooves B and radial grooves B, which are formed in the inner wall; the arc-shaped bulges B are concentrically distributed by taking the tube hole of the output tube part as a center; the circular arc-shaped grooves B are formed between every two adjacent inside and outside arc-shaped bulges B; the circular arc-shaped grooves B are communicated with one another through the radial grooves B; the radial grooves B are communicated to the tube hole of the output tube part and distributed in a radial manner; a plurality of reinforcing ribs are arranged at the bottom of the lower cover plate body. By adopting the technical scheme of the invention, the filtering membrane is less susceptible to damage, the intensity of the lower cover is high, the filter is less susceptible to blockage, and the filtering speed is stable and high.

The invention provides an offline abrasive particle extraction method which comprises the following steps: Step 1, firstly, manually shaking up an offline oil liquid for 30 seconds, putting the offline oil liquid into an ultrasonic machine, and oscillating for 30 minutes to uniformly mix the oil liquid and abrasive particles and avoid agglomeration and deposition of the abrasive particles; Step 2,diluting the oil sample, namely diluting the collected oil sample with kerosene at a ratio of 3: 1 so as to ensure that the used oil sample can smoothly pass through a filter membrane, separating theoil liquid from the abrasive particles by using a syringe filter, and cleaning a syringe by using kerosene; Step 3, taking the filter membrane out of the syringe filter, preparing a glass slide on the glass slide, dripping two drops of clear solution on the glass slide, and putting the filter membrane on the clear solution to ensure that one surface with the abrasive particles is positioned above; and putting the mixture on a constant-temperature table for drying; and Step 4, observing under a microscope. The technical problem that in the prior art, abrasive particles are connected with one another, and consequently analysis of the abrasive particles is inaccurate is solved.