45results about How to "Improve the lower limit of detection" patented technology

The invention discloses a particulate matter mass concentration detection device applied to atmosphere suspended particulate matters, and a method thereof. The particulate matter mass concentration detection device is composed of a particulate matter sampling unit, a particulate matter measuring sensor, and a signal processing unit; the particulate matter sampling unit comprises air pumps, a particulate cutting head, a high-efficiency gas filter, a gas flowmeter, gas conduits, and a sampling power supply; the particulate matter measuring sensor comprises a multichannel particulate measuring part, a high-stability laser, an optically trap, a sheath gas unit, a metal capillary, optical lenses, and high-performance photoelectric detectors; and the signal processing unit comprises a signal conditioning circuit, a data acquisition card, a computer, and a signal power source. The particulate matter mass concentration detection device is reasonable in design; manufacturing and installation are convenient; and measuring optical path pollution caused by particulate matters is not caused. The signal processing unit is simple in structure, and excellent in performance; and data processing and reading are both convenient to realize. The measured particulate matter mass concentration dynamic performance is excellent; precision is high; and linearity is high.

The invention discloses a method and a device for measuring sulfur content in coal by ultraviolet absorption spectroscopy. In the measurement method, the decomposition scale and a threshold are determined adaptively by combining empirical mode decomposition with 3sigma criterion, and non-stationary characteristics of differential absorption degree per se can be fully retained, so the spectral interference problem caused by dust, water vapor and background gas in combustion gas is effectively solved; the instantaneous concentration of SO2 is obtained through calculation according to the differential absorption degree after noise reduction and trend term removal, and the total sulfur content accumulated in the coal sample combustion gas is calculated through the gas flow; the sulfur content in the coal can be obtained by dividing the coal sample amount by the total sulfur content separated from the coal sample combustion; and the pretreatment process needed to be performed on the combustion gas by coulometric titration and an infrared absorption method is avoided. The device for measuring the sulfur content in the coal by the ultraviolet absorption spectroscopy comprises a combustion furnace, a measuring chamber, an ultraviolet light source, a spectrometer, an air purifying device, a flow meter, a waste gas treatment device, a computer, and the like.

The invention relates to a preparation method of a human IgG immunomagnetic bead (IMB) for staphylococcus aureus enrichment. With a magnetic bead as a carrier and human IgG as a recognition intermediate, the human IgG immunomagnetic bead is prepared through the processes of activation, coupling, washing and blocking. The human IgG immunomagnetic bead incubated in an appropriate buffer solution and under certain conditions can be used for high efficiency capture and enrichment of staphylococcus aureuses in a detection sample. The method of the invention has the advantages of strong specificity, high efficiency and rapidity, simple operation, low cost, and has no need for large equipment as well as specially trained professional operation personnel. Also, the sample needs no special pretreatment. Therefore, the method provided in the invention can be widely used for enrichment separation and detection of staphylococcus aureuses in food, feed, cosmetics, environment and clinics.

The invention relates to a preparation method and application of a miniature high-efficiency clenbuterol immuno-affinity chromatography column. The technical scheme is characterized by comprising the following steps of: preparing a high-quality antibody, synthesizing efficient prepared bromoacetyl chloride clenbuterol purified by a liquid chromatogram and thiolation hemocyanin into immunogen immune animals, and obtaining antiserum; reacting the purified bromoacetyl chloride clenbuterol with thiolation agarose to obtain clenbuterol-agarose padding, loading the padding into an antigen affinity chromatography column; and purifying a clenbuterol specific antibody in the antiserum by using the antigen affinity chromatography column. The preparation method of the clenbuterol immuno affinity chromatography column comprises the following steps of: coupling high-quality antibodies at high density to the agarose oxidized by periodic acid to prepare an antibody affinity padding, and placing 25 mul of padding in a small specially-made column to prepare the miniature immuno-affinity chromatography column. The immuno-affinity chromatography column provided by the invention can be used for specifically gathering clenbuterol in a sample to be tested at high efficiency and can increase the accuracy, reliability and sensitiveness of detection when being combined with an analytic instrument and colloidal gold test paper for use.

The invention discloses a composite gas sensing material, which comprises multiple layers of reduced graphene oxide. Zero-dimensional cuprous oxide quantum dots are loaded on the surface of the reduced graphene oxide, and one-dimensional cuprous oxide nanowires and / or three-dimensional cuprous oxide nanoparticles fill the gap between adjacent two layers of reduced graphene oxide. The invention also discloses a preparation method. The method comprises steps of preparing a mixed solution of a copper acetate solution and a graphene oxide dispersion solution, dripping a sodium hydroxide solution to the mixed solution to obtain breen precipitation, adding the precipitation to a reductant solution for a heating reaction to obtain black precipitation, and cleaning and sealing the black precipitation to obtain a composite gas sensing material. The invention also discloses a gas sensor made of the composite gas sensing material and applications of the gas sensor. The technical problem that thegas sensing material in the prior art can respond to the gas only by means of auxiliary means can be solved, the sensitivity to nitrogen dioxide at room temperature can be improved, and a response canbe given to ammonia at the room temperature.

The invention relates to the technical field of molecular biology, and discloses a kit and a method for detecting COVID-19 virus by combining nested isothermal amplification with gene editing. The kitcomprises: (1) a nested isothermal amplification system: adopting a nested amplification mode, wherein an outer primer pair is used for a first round of isothermal amplification, an inner primer pairis used for a second round of isothermal amplification, a product of the first round of isothermal amplification can be used as a template of the second round of isothermal amplification, and the inner primer pair is used for isothermal amplification; (2) a nucleic acid detection system based on gene editing: using a Cas13a protease and a specific probe to identify a nested RAA enriched templatewith a target sequence; and (3) a visual detection system: utilizing a transverse flow test strip to quickly judge whether virus molecules exist or not. The kit is simple and convenient to operate, does not need complex temperature control equipment, is rapid and efficient, can interpret a result in only one hour, has extremely high amplification efficiency, can detect five copied virus molecules,and is low in pollution risk.

The invention relates to a photoelectric detecting system, in particular to a stray light jamming resistance photoelectric detecting system based on digital phase locking. The system comprises a light source, a TTL signal generator, an optical modulator, a sensor, a pre-amplifier and a lock-in amplifier, wherein the TTL signal generator or the optical modulator perform modulation on the light source, a modulated modulation light source and stray jamming light are converted into output measuring signals and jamming signals through the sensor, the measuring signals and the jamming signals are transmitted to the lock-in amplifier after being amplified by the pre-amplifier, and the lock-in amplifier is set to be only allowed to be passed by the measuring signals with the same frequency characteristics as the lock-in amplifier. According to the system, the measuring signal-to-noise ratio can be remarkably improved, the measuring lower limit can be effectively expanded on the condition that the light source power is not increased, and the system is particularly applicable to a pollutant monitor with the weak measuring signals, and is also applicable to stray light suppression of other optical measuring instruments.

The invention provides a method for determining fluorine content in gypsum and silica. The method does not require ethanol to eliminate manganese, and uses alizarin S as an indicator, acetic acid-sodium acetate-sodium citrate-sodium chloride as a total ionic strength regulator. A fluoride ion selective electrode method is used to determine low levels of fluorine in gypsum and silica. The method can not only adjust the acidity and the ionic strength of the solution, but also mask the elements such as iron and aluminum in the solution. The method has high sensitivity, fast measurement speed, simple operation and small interference compared with other methods, and has good selectivity, which can provide accurate data.

The invention provides a mixed-potential low-ppm acetone sensor based on YSZ and a MNb2O6 (wherein M is one selected from a group consisting of Cd, Co, Zn, Mn and Ni) sensitive electrode and a preparation method. The mixed-potential low-ppm acetone sensor is mainly used for detection of diabetes. The sensor is successively composed of an Al2O3 ceramic plate with a Pt heating electrode, an YSZ substrate, a Pt reference electrode and the MNb2O6 sensitive electrode, wherein the reference electrode and the sensitive electrode are discrete and are symmetrically arranged on two ends of the upper surface of the YSZ substrate, the lower surface of the YSZ substrate is bonded with the Al2O3 ceramic plate equipped with the Pt heating electrode. According to the invention, the YSZ is used as an ionic conducting layer, and the MNb2O6 composite oxide material with high electrochemical catalytic activity is used as the sensitive electrode for construction of five sensing devices separately; and a device with higher sensitivity is obtained through comparison of acetone response values.

The invention discloses a sample preprocessing device provided with an ion chromatograph and used for detecting anions and a use method. The device comprises a sample liquid suck-in pipe, an absorption liquid storage bottle, a flushing liquid storage bottle, a sample liquid peristaltic pump, an absorption liquid peristaltic pump, a flushing liquid injection pump, a dialysis pool, an anion exchanger, a six-way valve, an absorption liquid storage ring and the ion chromatograph. The sample liquid peristaltic pump, the absorption liquid peristaltic pump, the ion chromatograph and the flushing liquid injection pump are all connected with a computer terminal. During dialysis, sample liquid flows, and absorption liquid stops flowing; when absorption liquid is transferred to the absorption liquid storage ring, sample liquid stops flowing, and absorption liquid flows; when the six-way valve is switched, the flushing liquid injection pump flushes absorption liquid in the storage ring to an anion enrichment column in the ion chromatograph. The device has the advantages of online removing heavy metal ions, being low in measurement limit, high in sample adaptability, mild in condition and free of toxic reagents, being matched with the ion chromatograph, and being capable of measuring various anions in sewage or acrylic fiber solvent within 20 min.

The invention relates to an immunomagnetic bead for aflatoxin B1 enrichment purification and a preparation method and application thereof. A carboxyl carboxyl serves as a carrier, an aflatoxin B1 monoclonal antibody serves as a recognition midbody, the immunomagnetic bead coupled with the aflatoxin B1 monoclonal antibody is prepared through the process of activating, coupling, washing and closing, and aflatoxin B1 in a detecting sample can be efficiently captured and enriched through incubation of the immunomagnetic bead in proper buffer liquid under certain conditions. The immunomagnetic bead for aflatoxin B1 enrichment purification has the advantages of increasing the concentration of aflatoxin B1 in the sample to be detected, improving the lower limit of detection, eliminating interference of impurities, improving detecting accuracy and reliability, shortening sample treatment time and achieving fast detection.

The invention discloses an online continuous gas sampling radioactivity measuring device which comprises a beta detector cathode, a beta detector anode and a gamma detector. The beta detector cathodeis of a hollow spherical shell structure, and the beta detector anode is a sphere; the beta detector anode is arranged in the beta detector cathode, and the sphere center of the beta detector anode coincides with the sphere center of the beta detector cathode; the beta detector cathode is insulated from the beta detector anode, and the gamma detector is arranged outside the beta detector cathode.The online continuous gas sampling radioactivity measuring device has the advantages that the online continuous gas sampling radioactivity measuring device capable of continuously sampling and simultaneously measuring beta and gamma is designed by the aid of the characteristic that beta and gamma rays can be simultaneously emitted by measured gas during nuclide decay, and has 4 pi detection stereoscopic angles for beta particles, beta and gamma measuring channels are matched with one another, accordingly, beta-gamma coincidence or anticoincidence measurement can be implemented, low radioactivity can be detected by the online continuous gas sampling radioactivity measuring device, and the lower limit of gas radioactivity detection can be improved during weak radioactivity measurement.

The invention relates to a graphene oxide aerogel solid-phase extraction column special for perfluoro acid compounds and a preparation method thereof. The solid-phase extraction column adopts grapheneoxide aerogel, and the preparation method comprises the following steps: firstly acquiring graphene oxide, then acquiring aminated graphene oxide hydrogel, then preparing aminated graphene oxide aerogel, and finally preparing the solid-phase extraction column. The graphene oxide aerogel prepared by the method does not need to use other polymer support materials, has excellent adsorption performance, can adsorb a lot of perfluoro acid compounds, has higher adsorption capacity and good adsorption effect, can quickly absorb target substances, and enables detection to be faster and more sensitive.

The invention relates to immunomagnetic beads for gathering purification of zearalenone and a preparing method and application of the immunomagnetic beads. The immunomagnetic beads coupled with zearalenone monoclonal antibodies are prepared through the process of activation, coupling, washing and enclosing with carboxyl magnetic beads as carriers and zearalenone monoclonal antibodies as recognition midbodies, the immunomagnetic beads are incubated in a proper buffer solution under a certain condition and can efficiently capture and gather zearalenone in a detection sample. The immunomagnetic beads for gathering purification of zearalenone have the advantages that the concentration of zearalenone in the detection is increased, the detecting lower limit is improved, interference of impurities is eliminated, the detection accuracy and reliability are improved, the sample treating time is shortened, and quick detection is achieved.

The present invention relates to an immunomagnetic bead used for vomitoxin enrichment purifying and a preparation method and application thereof, a carboxyl magnetic bead is used as a carrier, vomitoxin monoclonal antibody is used as an identifying intermediate, the immunomagnetic bead coupled with the vomitoxin monoclonal antibody is prepared by activation-coupling-washing-closed process, vomitoxin in a detection sample can be efficiently captured and enriched by incubation in certain conditions in a suitable buffer. The immunomagnetic bead used for vomitoxin enrichment purifying has the advantages of enrichment of concentration of vomitoxinin the to-be-tested sample, improvement of the lower detection limit, elimination of impurity interference, improvement of detection accuracy and reliability and reduction of sample processing time to achieve the rapid detection.

The invention discloses an organic fluorescent sensation probe for detecting Fe<3+>. A preparation method of the organic fluorescent sensation probe comprises the following steps: mixing an oily fluorescent sensation material with formic acid, and performing backflowing for 1 hour at 40-90 DEG C so as to obtain raw material probe molecules with protected groups; mixing the raw material probe molecules with tri-halogen phenol, and performing backflowing for 24 hours at 55-110 DEG C with a catalyst, thereby obtaining the organic fluorescent sensation probe. The organic fluorescent sensation probe is good in water solubility, good in biocompatibility and wide in inspection range, the advantages that an organic fluorescent probe is good in material specificity and high in sensitivity are maintained, the lower detection limit of iron ions can be greatly increased, and the lower detection limit of the probe is at a world leading level.

The invention relates to a fluorescence type glucose capillary biosensor. The biosensor comprises nano sensors, a capillary coupling device, capillaries, a light source, a fiber optic spectrometer and a probe, wherein the nanometer sensors are distributed on the inner walls of the capillaries; the capillary coupler is connected with optical fibers and hoses; the optical fibers can be used for receiving an exciting light generated by the light source; the hoses can be used for receiving liquid to be detected; and a new fluorescence spectrum generated by the liquid to be detected and the nano sensors under the excitation of an evanescent field produced by the exciting light is received by the probe, and the probe transmits the received fluorescence spectrum to the fiber optic spectrometer to be analyzed. According to the fluorescence type glucose capillary biosensor, the capillaries are adopted for sampling, thus the dosage of samples to be detected can be obviously decreased, and reagents are saved. A fluorescence signal is excited through the evanescent field, therefore, the background fluorescence in a biological sample can be reduced efficiently, and the lower detection limit can be elevated.

The invention discloses a detection system of an oil-consuming device, belongs to the technical field of electrical detection equipment, and solves the technical problem of low efficiency of an oil paper aging detection mode in the prior art. The detection system comprises: a light source device capable of emitting at least two laser beams; a light source modulation assembly which can modulate a light source and / or change the energy level of the light source; a beam expanding and collimating device which is used for aggregating or combining different light sources; a detection assembly which can store air in an oil bin in the oil consuming device and can enable the light source aggregated by the beam expanding and collimating device to penetrate through the stored air, wherein the energy level and modulation of laser emitted by the light source device are changed through the light source modulation assembly, the laser is aggregated through the beam expanding and collimating device, andthe aggregated laser enters the detection assembly to complete the detection of the insulating oil paper. The detection system is used for perfecting the use function of an oil device, and meets therequirement of people for high insulation oil paper detection efficiency.

The invention discloses a biological sample detection method and a detection kit. The method comprises the following steps: forming a ternary complex (magnetic bead-antigen-marker) in a manner of immunospecific binding with magnetic beads, and collecting the ternary complex under the action of a magnetic field; under a specific chemical reagent, eluting a markers in the ternary immune complex, separating the markers from magnetic beads under the action of the magnetic field, and collecting eluent containing the markers, and re-dispersing the eluent by using strong electrolyte; and detecting the eluent containing the markers and then, realizing absolute quantification through a nano-particle counter. The method disclosed by the invention can be used for detecting trace protein below the lower limit of conventional immunodetection, and can be widely applied to the fields of immunological detection, microbiological detection, cell separation and the like.

The invention particularly relates to a method for rapidly determining the content of sulfite in industrial sulfuric acid, which belongs to the technical field of chemical analysis and detection, andcomprises the following steps: taking an industrial sulfuric acid sample with the mass of m, and performing preparing to obtain a solution to be detected; titrating the to-be-detected solution by adopting a closed titration device to obtain the volume V of a standard titration solution consumed at a titration end point; setting a blank test group, and obtaining the volume V0 of the standard titration solution consumed at the titration end point; obtaining the content of sulfite in the industrial sulfuric acid according to m, V and V0; the closed titration device comprises a conical flask, a rubber plug, a glass gas-guide tube, a burette and a magnetic stirrer, wherein the rubber plug is tightly plugged at the opening of the conical flask; the glass gas-guide tube and the burette respectively penetrate through the rubber plug, so that one end of the glass gas-guide tube and one end of the burette extend into the conical flask and are respectively used for introducing nitrogen, discharging oxygen and titrating a solution of the conical flask; and the magnetic stirrer is positioned at the bottom of the conical flask and is used for stirring the solution in the conical flask.

The invention relates to the detection field, and specifically relates to a method of utilizing a diagnostic marker to evaluate the early stage toxicity of trace exogenous chemicals and applications thereof. The diagnostic marker is one or more of L-valine, N-actyl-L-aspartic acid, lysolecithin, creatinine, and 2-phosphoglyceric acid. People find that exogenous chemicals can break the balance of amino acids in zebra fish and influence the decomposition and metabolism of proteins; the disturbance in the growth period is associated with the mechanism of toxicity; and the inventor finds that thesensitivity of a toxicity predicting method can be largely improved by combining a zebra fish model with metabonomics. Thus, the change of the zebra fish metabolite index can be used to judge the early stage toxicity of exogenous chemicals.

The invention discloses a liquid chromatogram-inductively coupled plasma mass spectrometry detection method of vitamin B12. According to the liquid chromatogram-inductively coupled plasma mass spectrometry detection method of vitamin B12, high performance liquid chromatography and inductively coupled plasma mass spectrometry are combined, so that the obtained liquid chromatogram-inductively coupled plasma mass spectrometry detection method of vitamin B12 is stable and reliable, is high in anti-matrix interference performance, low in detection limit, simple in operation, and high in speed, and is especially suitable for determination of vitamin 12 in food, and novel reference is provided for detection and analysis of vitamin B12 in food.

The invention discloses a conical space compression plasma detection system, a space compression technology is applied in plasma detection, and the ability of plasma detection of various elements and the detection lower limit are enhanced. The conical space compression plasma detection system is a system which can independently complete element detection and material component content detection; the system is mainly composed of a light source module, a conical compression module, a sample module, a detection module, a logic module and a display module; the logic control module is connected with the control module, the detection module and the display module; the control module achieves manipulation of the light source module and the detection module; the light source module completes work of light on the sample module through the conical compression module; the detection module is used for collecting information of the sample module and transmitting to the logic module. The plasma detection system has better detection precision and lower detection lower limit than those of a traditional system, and can realize zero pretreatment of samples.

The embodiment of the invention discloses a detecting system for test paper. The system comprises a detecting unit used for information collection, and a colorimetric photosensitive device used for information processing and analysis, wherein the detecting unit is a black detecting card; the colorimetric photosensitive device comprises a light-emitting unit, an optical imaging unit and a photoelectric processing unit. The detecting system has more accurate analytical sensitivity, and through the adoption of the detecting system, the lower limit of the detection of products can be effectively improved, and the range of clinical detection can be enlarged.

The invention discloses an electromagnetic acceleration enhanced plasma detection system which combines electromagnetic acceleration with a laser plasma excitation detection technique. The electromagnetic acceleration enhanced plasma detection system provided by the invention is a system capable of completing material element and component content detection. The detection system mainly comprises a light source module, an electromagnetic acceleration module, a sample module, a control module, a probing module, a logic module and a display module; the logic module is connected with the control module, the probing module and the display module; the control module realizes the control on the light source module, the electromagnetic acceleration module and the probing module; light emitted from the light source module irradiates a to-be-detected object on the sample module and induces plasma, the plasma enters the probing module under the action of the electromagnetic acceleration module, and the detection collects sample module information and transfers the sample module information to the logic module. The electromagnetic acceleration enhanced plasma detection system provided by the invention has better probing precision and lower detection limit, and realizes zero pretreatment on a to-be-detected sample.