141results about How to "Simplify preprocessing steps" patented technology

The invention discloses a water level measuring system and a water level measuring method based on digital image processing. The water level measuring system comprises a spherical buoy, a fixing rod, an image acquisition module, an image transmission module and an image processing module. The water level measuring method comprises the following steps: floating the spherical buoy along the fixing rod up and down through raise and fall of the water level; shooting a water surface by a positioned and orientated image acquisition module; transmitting an image to an image processing device by the image transmission module; and after the image processing device acquires the image, converting the image into a YUV (luma and chroma) color processing model, performing binarization processing, extracting out a spherical buoy object by a binary image connective region growing notation method, extracting out the edge of the spherical buoy object through edge detection, working out spherical center coordinates of the spherical buoy according to edge pixel coordinates of the extracted image, and thus working out the current water level height. The water level measuring system and the water level measuring method are not affected by water temperature, water quality, sediment concentration and other outside interference factors and are strong in adaptability; and the water level measuring system is simple in composition, convenient to install and easy to use.

The invention provides a method of using a composite extracting agent for extraction and refining of phosphoric acid prepared through a wet process. The method successively comprises the procedures of pretreatment, extraction and refining and post-treatment, wherein in the procedure of pretreatment, the content of solid in extracted raw acid obtained after condensation, defluorination, sedimentation, decolouring and filtration is less than 0.05 wt%, in the procedure of extraction and refining, a composite extracting agent is used for countercurrent contact extraction and comprises ketone ether, alcohol and ester, the weight ratio of ketone ether to alcohol to ester is 60-80: 15-20: 5-15, the ketone ether comprises ketone and ether and the weight ratio of ketone to ether is 95-60: 5-40, and in the procedure of post-treatment, condensation, decolouring, desulphurization, condensation and filtration are carried out so as to obtain the product of 85% industrial phosphoric acid. The invention has the advantages of low requirements to extracted raw acid, low production cost, a good extraction effect and capability of producing more products of industrial phosphoric acid.

The invention discloses a method for detecting catecholamine in blood plasma by liquid chromatography tandem mass spectrometry. The method comprises the following steps of preparing a standard product, separating by liquid chromatography, detecting by a mass spectrum, drawing a standard curve, and detecting the catecholamine in the blood plasma. The method has the beneficial effects that the catecholamine is detected by innovatively applying a high-flux liquid chromatography tandem triple quadrupole mass spectrograph; protein is precipitated by acetonitrile, dansyl chloride is used for performing derivative reaction, and the liquid chromatography tandem triple quadrupole mass spectrograph is used for detecting after extraction, so that the pretreatment steps are simple, the interference of a matrix in the blood plasma is effectively removed, and the specificity is good; after the derivatization of dansyl chloride, the detection sensitivity is effectively improved; the high-flux liquid chromatography tandem rod mass spectrograph is used for detecting, three types of catecholamine, including dopamine, epinephrine and norepinephrine, in the blood plasma can be quantitatively and accurately detected; the detection time is short, the flux is high, the detection sensitivity is high, the specificity is good, and the cost is low.

The invention belongs to the technical field of load prediction, and particularly relates to a stack type self-encoding multi-model load prediction method and system based on LSTM. The method comprises the following steps: acquiring a data set, and preprocessing the data set; establishing a probability model of the charging start time of the electric vehicle and reconstructing a data set; constructing an LSTM stack type self-coding structure and training the LSTM stack type self-coding structure; and predicting a short-term load by utilizing the XGBoost model, and carrying out index evaluation. The system comprises a data set acquisition module, a preprocessing module, a probability model and reconstruction module, an LSTM stack type self-coding structure construction and training module,a prediction module and an index evaluation module. The method provided by the invention can consider the influence of the charging load of the electric vehicle, utilizes the original data to the greatest extent, deeply learns the internal features, and effectively improves the short-term load prediction precision.

The invention discloses a pretreatment method for determining multiple heavy metal elements in soil simultaneously. The pretreatment method comprises steps as follows: step (1): sample weighing: the soil is air-dried, ground and screened with a nylon sieve, a soil sample is weighed and put into a microwave digestion tube through a polytetrafluoroethylene long-neck funnel, and the funnel is slightly flapped before the funnel is removed so that all the soil sample attached to the wall of the funnel enter the digestion tube; step (2): digestion: nitric acid, hydrochloric acid and hydrofluoric acid are added to the digestion tube, a cover is screwed down, and the digestion tube is put into a microwave digestion instrument for digestion; step (3): acid driving: after microwave digestion is finished, hydrogen peroxide is added to the digestion tube; then the microwave digestion tube is put into a temperature-controlling acid driver in a fume cupboard for direct acid driving until the volume is smaller than 1 mL, then a solution is directly transferred to a volumetric flask, the volume is constant, and a to-be-tested solution is obtained. With the adoption of the pretreatment method, the digestion speed of the sample can be increased, the pre-treatment step of the sample is simplified, and the accuracy of the detection analysis result is guaranteed.

The invention provides a method for quantitatively detecting six kinds of nitrobenzene compounds in fine atmospheric particles PM2.5. The method comprises the following steps: acquiring a sample, extracting the sample, concentrating and purifying the sample and quantitatively detecting by adopting chromatography-tandem mass spectrometry. By optimizing parameters of secondary mass spectrometry conditions, the method is better in selectivity and higher in sensitivity on target compounds in comparison with an existing detection method reported in literature. According to the method, the disadvantage that the selectivity and the sensitivity of a conventional detector in the process of detecting the trace quantity of nitrobenzene compounds in a complex background matrix cannot be ensured at the same time is overcome by virtue of a gas chromatography/tandem mass spectrometry selective reaction monitoring technology, and the qualitative operation is accurate and reliable, so that the method has very remarkable advantages in comparison with conventional GC/ECDs (gas chromatography/election capture detectors), GC/NPDs (gas chromatography/nitrogen-phosphorus detector), GC/LRMS (gas chromatography/low resolution mass spectrometry) detectors or GC/HRMS (gas chromatography/high resolution mass spectrometry) detectors.

The invention relates to a method for rapidly extracting and measuring plastid pigment in tobacco and tobacco products, comprising the following steps: (1) a method of ultrasonic extraction is adopted to rapidly extract the plastid pigment in tobacco and tobacco products; (2) after ultrasonic extraction, the content of all the components in the extracted plastid pigment is measured by high performance liquid chromatography. The invention adopts the high performance liquid chromatography to rapidly measure the extracted plastid pigment, and the content of all the components in the plastid pigment can be rapidly and exactly measured, thus greatly improving the measuring accuracy. By adopting the extracting and measuring method, the working efficiency is greatly improved, and the cost is also reduced. Therefore, the invention has good social and economic values, and is easy to popularize and apply.

The invention relates to the technical field of detection of synthetic pigments and especially relates to a method of simultaneously detecting various synthetic pigments in wheaten foods via HPLC-DAD.The method includes the following steps: A) preparation of standard work solutions and samples; b) extraction of a sample solution; C) HPLC-DAD analysis to the solution prepared in the step B); D) calculation of content of to-be-detected substances with standard curve. In the HPLC-DAD detection method, pretreatment steps are simplified, wherein solid-phase extraction and concentration steps are avoided, thus reducing pretreatment time. Detection is carried under wavelength of 400-600 nm, so that interference due to majority of food additives and natural pigments is avoided. The method is accurate, quick and simple, has reliable quantitative results, can effectively detect ten artificially synthetic pigments in one time, and is very suitable for simultaneously treating samples in multi-batches.

The invention relates to an analysis method for rapidly screening pesticide and metabolite residue in tea. The analysis method comprises the steps of analyzing by Sin-QuEChER dispersive solid-phase extraction combined with an ultrahigh performance liquid chromatography-quadrupole-static field rail well high-resolution mass spectrum method; extracting a sample with 0.1% formic acid acetonitrile solution; performing salt precipitation oscillation and centrifugation; further purifying with Sin-QuEChERS Nano dispersive solid-phase extraction column; performing separation with Thermo Accucore aQ (2.1 millimeter by 150 millimeter and 2.6 micrometers) chromatographic column, and performing gradient elution with methyl alcohol, 0.1% methyl alcohol and 5mmol/L ammonium formate solution; and analyzing in a Full MS/ddMS2 scanning mode under a positive ion mode. The method is simple, convenient, rapid, efficient and accurate in handling process and can be used for rapidly screening multiple pesticide and metabolins in the tea.

The invention discloses an analytical method for identifying Chinese date honey and syrup-adulterated with fake Chinese date honey, and particularly relates to a method by applying the ultra-high performance liquid chromatography-quadrupole rod-orbitrap high resolution mass spectrum technique combining metabonomics. The method comprises the steps that firstly, a true Chinese date honey sample and a syrup-adulterated with fake Chinese date honey sample to be detected are pretreated by organic solvent respectively, separation and determination of chemical components in the pretreated samples are achieved by applying an ultra-high performance liquid chromatography-quadrupole rod-orbitrap high resolution mass spectrometry method, then obtained UHPLC-MS original data of the true Chinese date honey sample and the Chinese date honey sample to be detected is preprocessed, and finally true Chinese date honey and syrup-adulterated with fake Chinese date honey are distinguished by applying principal component analysis of a multivariate statistical analysis method. According to the analytical method, after metabolin information of Chinese date honey and syrup-adulterated with fake Chinese date honey is obtained comprehensively, combined with multivariate statistical analysis, Chinese date honey and syrup-adulterated with fake Chinese date honey are analyzed comprehensively, and the detection of syrup-adulterated with fake Chinese date honey is completed.

The invention discloses an analysis method of identifying black locust honey and syrup adulterated black locust honey, and particularly relates to a method of combining an ultra-high performance liquid chromatography-quadrupole rod-orbitrap high resolution mass spectrum technique and metabonomics. The analysis method comprises the following steps: respectively pre-processing a genuine black locust honey sample and syrup adulterated black locust honey to be detected by adopting an organic solvent, realizing the separation and determination of chemical components of the preprocessed sample by applying an ultra-high performance liquid chromatography-quadrupole rod-orbitrap high resolution mass spectrum method, then preprocessing the obtained UHPLC-MS original data of the genuine black locust honey sample and the black locust honey sample to be detected, and finally analyzing main components by using a multivariate statistical analysis method so as to identify the black locust honey and the syrup adulterated black locust honey. The analysis method has the beneficial effects that the black locust honey and the syrup adulterated black locust honey are comprehensively analyzed by multivariate statistical analysis after the information of metabolites of the black locust honey and the syrup adulterated black locust honey are comprehensively obtained, thereby completing the detection of the syrup adulterated black locust honey.

The invention relates to a method for simultaneously detecting a nitrofurans raw drug residue in an aquatic product, comprising the following steps of: (1) preparing four types of mixed standard solutions; (2) preparing a sample; (3) extracting; (4) concentrating; (5) purifying; and (6) detecting. The method disclosed by the invention has the characteristics of high flexibility, simplicity and convenience in operation, low detection cost, accuracy and reliability; and the quantitative limit is 5 micrograms/kilogram and the recycling rate is more than 70%, so that the method is suitable for rapidly detecting imports and exports of the aquatic product.

The invention discloses a sensitization-free chemical nickel-plating method of conducting glass and belongs to the technical field of chemical plating. The sensitization-free chemical nickel-plating method of conducting glass is suitable for chemical nickel-plating of indium tin oxid (ITO) conducting glass and fluorine-doped tin oxide (FTO) conducting glass. The sensitization-free chemical nickel-plating method of conducting glass comprises six steps of oil removal, coarsening, glue removal, catalysis, activation and chemical nickel-plating. The sensitization-free chemical nickel-plating method is a nickel-plating method suitable for conducting glass and having good selectivity to a glass conducting surface. A planting layer obtained by the method has good adhesion with base glass and high brightness and can obviously improve conductivity of a glass conducting surface. The sensitization-free chemical nickel-plating method of conducting glass adopts raw materials having a wide source and low costs, and is suitable for metallization treatment on mobile communication terminal capacitive touch screen (ITO, FTO) line terminals.

The present invention discloses a method for simultaneously measuring acetic acid vinyl ester and 6 benzene series substances in water-based adhesive. The method comprises: dispersing samples by using N-N dimethylformamide, quantifying by using double internal standard methods and simultaneously measuring 7 compounds in cigarette water-based adhesive by using a headspace-gas chromatography-mass spectrometer during one sample injection; under adopted chromatographic conditions, chromatographic peaks of benzene, toluene, ethylbenzene, orthoxylen, m-xylene/p-xylene (m-xylene and p-xylene are not separated due to problems of a chromatographic column, but the calculation results are not influenced), and acetic acid vinyl ester target substance as well as two internal standard substances, namely isobutanol and 2-hexanone, are separated well. Results show that the regression equation correlation coefficient of each component reaches 0.999 or more, the quantitative determination limit of the benzene series substances is 0.01-0.02mg/kg, the quantitative determination limit of acetic acid vinyl ester is 0.10mg/kg, the mean relative standard deviation is 1.15%-3.75%, the adding standard recovery is 88.09%-95.44%; the method is fast, accurate, good in repeatability, high in recovery rate, good in practicability, and the like.

The invention relates to preparation and applications of a magnetic composite porous network adsorbing material, wherein the preparation method comprises: (a) preparing a magnetic porous organic framework material with strong adsorbability and large specific surface area by adopting an in-situ growth method, and (b) synthesizing a novel composite porous network adsorbing material with a core-shellstructure through a sonogashira coupling reaction so as to achieve the selective adsorption and efficient enrichment of food and environment pollutants. According to the present invention, the prepared magnetic composite porous network adsorbing material has good particle size uniformity and significantly efficient adsorption capacity on target pollutants, the separation step during solid-phase extraction is greatly simplified due to the magnetic characteristic of the material, and the microporous organic coating changes the hydrophobicity of the surface of the material, such that the material has high stability in a humid environment, can well play a role in an organic solvent, and is suitable for adsorption and enrichment of various food pollutants.

The invention provides a method for quantitatively detecting organophosphorus pesticide chlorpyrifos in environmental air, and belongs to the field of detection methods for pesticide residues. The method comprises collection of a sample (comprising a gas phase part and a particulate matter part), pretreatment of the sample and chromatography-tandem mass spectrometry quantitative detection. Compared with reported methods, the detection of the chlorpyrifos in the environmental air is higher in selectivity and higher in sensitivity through the optimization of parameters of a chromatography-mass spectrometry detection method. According to the method, by the use of a multi-reaction monitoring technology of high performance liquid chromatography/tandem mass spectrometry, the shortcoming that a conventional detector cannot have the selectivity and the sensitivity at the same time during detection of a trace chlorpyrifos compound in a complicated background matrix is overcome, and qualitation and quantitation are more accurate and reliable. Therefore, compared with conventional UV-Vis, HPLC/PDA, GC/ECD and GC/NPD, the method provided by the invention has very outstanding advantages.

The invention relates to a novel saliva preserving fluid comprising the following components: 1-10mmol/L of EDTA, 1-50mmol/L of Tris-HCl, 10-100 mmol/L of sodium chloride; 0.1-3% (w/v) of sodium sorbate, 0.1-3% (w/v) of sodium diacetate, 0.01-0.1% (v/v) of proclin 300, 0.1-1% (v/v) of TWEEN20, 0.1-1% (w/v) of NP40 and 0.1-2% (w/v) of SDS. The novel saliva preserving fluid is used for preservingsaliva samples, can effectively inhibit nuclease activity, prevent microbial pollution, guarantee DNA fragment integrity and purity, simplify pretreatment steps, is suitable for centrifuge-free and low-temperature environments, can guarantee transport stability of samples among different places, and is suitable for molecular epidemiological large-scale population investigation and research.

A direct current glow discharge mass-spectrography method for determination of impurity elements in high purity alpha-Al2O3 comprises the following steps: (1) evenly mixing Al2O3 powder and copper powder according to the proportion, then tabletting the mixed powder, blowing away the powder on the surface of the sample with N2, and filling the sample into a sample pool; (2) setting the flow of discharge gas at 500 mL / min, discharge current of 30 mA and ion source cooling temperature at 5-25 DEG C, and pre-sputtering for 15 min; (3) acquiring the signal intensity of the element to be measured under the experimental conditions set in step (2), defining the total sum of signal intensity generated by Al, O and Cu as 100%, and calculating the element content to be measured in the mixed powder according to the ratio of the signal intensity of the element to be measured to the total signal intensity of the three elements Al, O and Cu; and deducting the content of the element to be measured in the copper powder to obtain the content of the element to be measured in Al2O3. The invention realizes the determination of the content of impurity elements in non-conductive alpha-Al2O3 powder by the direct current glow discharge mass-spectrometry method, and the determination results are basically consistent with those of the DC arc emission spectroscopy method.

The invention discloses a pre-treatment method for simultaneously determining rare-earth elements and lead of tea leaves and belongs to the field of analysis chemistry. The pre-treatment method disclosed by the invention comprises the following steps: (1) pre-digesting; (2) digesting with nitric acid; (3) digesting with H2O2; (4) removing acid; and (5) making up to constant volume. Compared with a digestion method for rare-earth elements and lead of tea leaves, regulated by standards in China, the pre-treatment method has the advantages that a required digestion device is simple so that the pre-treatment method is easy to popularize; meanwhile, needed reagents are few and thus the influences on the detection of a reagent blank are reduced; and a digestion step is simple and is easy to control in actual operation. The uniform pre-treatment method is used for treating a tea leaf sample, so that the problems in a detection process of the rare-earth elements and lead of the tea leaf sample that a pre-treatment method is complicated and digestion methods are different are solved; and the pre-treatment steps are greatly simplified, the detection efficiency is improved, the detection cost is reduced and the pre-treatment method is worthy of popularization and promotion.

The invention discloses an external standard measurement method for benzene and benzene series in glyceryl triacetate by adopting headspace-gas phase mass spectrometry. Benzene and benzene series in glyceryl triacetate are determined by using a headspace-gas phase mass spectrometry method; the quantity is fixed by adopting the external standard method, in combination with optimization measures such as taking chromatographic pure glyceryl triacetate as a solvent and a matrix correction agent, and a sample pretreatment method, the detection chromatographic condition is specifically determined, relatively good chromatographic peak separation effects of benzene, methylbenzene, ethylbenzene, o-xylene, m-xylene and paraxylene are ensured, and the external standard measurement method has relatively good linear dependence. The detection limit of benzene and benzene series is 0.01-0.02mug/mL; the relative standard deviation is 1.1%-4.8%; the recovery rate is 89.9%-97.1%; the error and complicated operation caused by sample pretreatment are effectively reduced; and the treatment time is also greatly reduced.

The invention relates to application of biogenic amine serving as a feature mark in bee venom type identification and further relates to a method for identifying types of bee venoms through the biogenic amine as the feature mark by means of HPLC/MS/MS methods. According to the method, one or more of histamine, dopamine, serotonin, epinephrine and noradrenaline serves as the feature mark, one or more of Italian bee venom, royal jelly high-yielding bee venom, Anatolia bee venom, Caucasia bee venom, Carniolan bee venom and Carpathian bee venom can be precisely identified. The method can efficiently, stably and accurately identify six types of bee venoms, and has significance on reinforcing study on bee venom type identification, exploring bee venom traceability information, developing traditional Chinese medicine, improving bee venom quality in China and guaranteeing health of consumers.

The invention discloses an extraction agent for preparing industrial phosphoric acid through a hydrochloric acid method and an extraction method thereof. The extraction agent comprises, by mass, 10-50% of one or two of tributyl phosphate or tributoxy ethyl phosphate, 15-40% of one or multiple of n-butyl alcohol, isooctanol, cyclohexanol, isopropanol and isoamylol, 10-30% of one or two of n-butyl ether, isopropyl ether and diisopropyl ether, 5-30% of one or multiple of high-carbon ketone, aliphatic amine or quaternary ammonium salt and 1-10% of one or multiple of oil-based polyoxyethylene ether phosphate, octyl sodium sulfate, alpha-alkenyl sodium sulfonate, sodium lignin sulfonate, stearyl sulfo succinamide disodium and lauryl ammonium sulfate. The extraction agent is wide in application condition, low in solvent loss and convenient to recycle, and extraction rate can reach higher than 80%.

The invention discloses a heat-reduction metallization copper plating process for a carbon fiber surface, which belongs to the technical field of modification methods for the carbon fiber surface. The process comprises the following steps: pretreatment of a carbon fiber; preparation of a pre-plating liquid; dipping; heat-reduction copper plating; etc.; wherein the process is carried out in a micro-aerobic carbon environment, N2 is used as protection and dilution gas, reduction temperature is 650 to 700 DEG C, reduction time is 40 to 50 min, and the pH value of the pre-plating liquid is 11 to 12. Compared with chemical copper plating and electrical copper plating of the carbon fiber, the copper plating process provided by the invention has the following advantages: since a micro-aerobic carbon atmosphere is employed for reduction of a copper salt, the two major steps of sensitization and activation before copper plating are omitted, usage of precious metals like AgNO3 and PdCl2 is reduced, experiment cost is reduced, and a pretreatment step is simplified. According to XRD and EDS analysis, a great amount of copper is attached onto the carbon fiber surface after copper plating, reaching a certain coverage ratio; and according to SEM observation results, the copper on the carbon fiber surface is distributed on the carbon fiber surface in a superposed island shape.

The invention discloses a detection method of phenolic compounds in a carbonate ester food packaging material and belongs to the technical field of analysis and detection of packaging materials. The detection method comprises the following steps: (1) preparing a standard solution; (2) optimizing liquid chromatographic conditions; (3) optimizing mass spectrum conditions; (4) determining a linear range and detection limit; (5) pre-treating a sample; (6) detecting the sample. According to the detection method disclosed by the invention, a quantitative analysis method for simultaneously determining nonylphenol, octylphenol, cumylphenol and bisphenol A in a polycarbonate material food contact material through a high performance liquid chromatography-tandem mass spectrometry, and the quantitative analysis method is rapid and accurate and has high sensitivity; a pre-treatment step is simple and a simple and reliable analysis method is provided for raw material control and finished-product quality control of production enterprises of wide food-grade contact materials of China.