36results about How to "Improve qualitative accuracy" patented technology

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 provides an LC-Q-TOF/MS detection technology for 544 pesticide residues in kernel fruit. In a TOF/MS mode, the LC-Q-TOF/MS detection technology separately determines the retention time of each pesticide standard under designated gas chromatography-mass spectrography conditions, determines the ionization form and chemical formula of a compound under the condition of an ESI source and acquires the accurate mass number of the parent ion of each compound so as to form a TOF/MS database. In a Q-TOF/MS mode, the LC-Q-TOF/MS detection technology separately acquires the fragment ion mass spectrum of each pesticide standard under the condition of three to five different collision energies and introduces acquired information into PCDL software so as to form a Q-TOF/MS database. Through comparison of the retention time, mass spectrometry information and tandem mass spectrometry information of a kernel fruit sample, whether the sample contains pesticide residues or not can be determined; and compounds with high primary scores are subjected to secondary confirmation, and if secondary scores are high, it is confirmed that related pesticide residues are detected. The LC-Q-TOF/MS detection technology provided by the invention has the advantages of fastness, high throughput, high accuracy, high reliability and the like, and can accurately screen pesticides in the kernel fruit.

The invention discloses a tea volatile aroma component analysis method based on the full-two-dimension gas chromatography-flying time mass-spectrometric technology. The method comprises the first step of tea volatile component preparing, the second step of full-two-dimension gas chromatography-flying time mass spectrometric analyzing and the third step of volatile component software qualitative analyzing. The method has the advantages that sensitivity is high and repeatability is good. Hundreds of volatile components can be analyzed at the same time. The method is suitable for basic studies related to tea characteristic aroma substances and tea classified studies.

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 discloses a method used for detecting caffeic acid content in cigarette sidestream smoke by high performance liquid chromatography-tandem mass spectrum. The method comprises following steps: (1) total particulate matters in smoke are collected by a fishtail cover and a filter disc; (2) the filter disc is placed in a methanol solution containing internal standard substances for extraction so as to obtain an extract; (3) the extract is filtered, and then is detected by a high performance liquid chromatography-tandem mass spectrometer; and (4) the content of caffeic acid is quantitatively analyzed by internal standard method. According to the method used for detecting caffeic acid content in cigarette sidestream smoke by high performance liquid chromatography-tandem mass spectrum, pre-treatment is simple, separating effect is excellent, qualitative analysis is accurate, sample analysis time is short, and detection sensitivity is high.

The invention provides an LC-Q-TOF/MS detection technique for 544 pesticide residues in solanaceous fruit vegetables. In a TOF/MS mode, LC-Q-TOF/MS measures the retention time of each pesticide standard substance under specified chromatographic and mass spectrometric conditions, an ionization form and a chemical formula of each compound under an ESI source are determined, the exact mass number for parent ions of each compound is obtained, and a TOF/MS database is formed. In a Q-TOF/MS mode, fragment ion mass spectra of each pesticide standard substance in 3-5 different collision energies are collected respectively, the collected information is introduced into PCDL software, and a Q-TOF/MS database is formed. Through comparison of the retention time and first-level mass spectrometry and second-level mass spectrometry information of solanaceous fruit vegetable samples, whether the samples contain the pesticide residues is determined, compounds having higher first-level score are subjected to second-level confirmation, and if the second-level score is higher, related pesticide residues are confirmed to be detected out. The method has the advantages of high speed, high throughput, high precision, high reliability and the like, and can accurately screen the pesticides in the solanaceous fruit vegetables.

The invention relates to a data positioning identifying and storing method and system. The data positioning identifying and storing method comprises the steps of acquiring case images of patients involved in tests, positioning each identification item according to a predefined case template, calling a corresponding identification engine to carry out identification according to data types corresponding to the identification items, carrying out judgment of the data types on identification results, and lastly storing the identification results to corresponding data diagrams in a database. Subsequent targeted check and verification can be carried out conveniently, the workload of check is reduced, troubles and energy are saved, and using cost is reduced greatly. When specific identification is carried out, identification will not be carried out on general names of the identification items such as 'gender', 'birth date' and other fixed characteristics and is only carried out on the characters after the general names, therefore, quick identification is carried out, and identification time is saved.

The invention discloses an in-situ visual determination method for enzyme activity in plants under environmental stress. The in-situ visual determination method comprises the following steps: plant pretreatment; enzyme spectrum imaging; standard curve production; and image processing. The invention provides the in-situ visual determination method of enzyme activity in plants under pollutant stress, and makes up the technical blank of plant leaf enzyme spectrum in the prior art. Meanwhile, by providing a series of image processing means, a leaf enzyme spectrum high-quality image is reconstructed, so that useful information of qualitative accuracy is improved, and the method has greater application prospects.

The invention discloses a method for detecting urotropine in cigarette side stream smoke through high performance liquid chromatography-tandem mass spectrometry. The method comprises the following steps: trapping the urotropine in cigarette side stream smoke by utilizing a glass fiber filter disc, extracting the filter disc with acetonitrile, cleaning a fishtail cover and a pipeline, respectively taking 0.5mL of extracting solution and 0.5mL of cleaning solution, merging the solutions, purifying through an organic phase filter membrane, detecting through LC-MS/MS, and analyzing the content of the urotropine in the cigarette side stream smoke. The content of the urotropine in the cigarette side stream smoke is measured by adopting LC-MS/MS, qualitative detection is performed by adopting a MRM (Multi-Reaction Monitoring) mode, the qualitative accuracy and the sensitivity of the method can be effectively improved, and the method is suitable for measuring the urotropine in various cigarette side stream smokes. The application range is wide, the measurement is accurate, and the method is simple and environment-friendly and has high practicality.

The invention discloses a method and a device for simultaneously detecting three metabolic products of chlorpyrifos in urine. The method comprises the following steps: (A) target compounds selection: selecting 3,5,6-trichloro-2-pyridoxol, triethyl phosphate and diethyl thiophosphate; (B) sample enzymolysis; (C) sample extraction; (D) sample purification and concentration; (E) instrumental analysis. The device mainly comprises a main body and a chromatography-ion tandem mass spectrum detector, wherein the main body comprises a power supply unit, a thawing unit, a centrifugal device I, a water bath device, a turbine mixing device, a centrifugal device II, a purification device, a rotary evaporation device and a PLC (programmable logic controller). According to the method disclosed by the invention, the detection effectiveness and the detection reliability are greatly improved, and the detection time and the detection cost are saved.

The present invention establishes a LC-Q-TOF/MS detection technology for 544 kinds of pesticide residues in melon vegetables. LC-Q-TOF/MS in TOF/MS mode, respectively measure the retention time of each pesticide standard under the specified chromatographic mass spectrometry conditions, determine the ionization form and chemical formula of the compound under the ESI source, and obtain the parent ion of each compound Accurate mass number of the TOF/MS database. In the Q-TOF/MS mode, the fragment ion mass spectra of each pesticide standard were collected under 3-5 different collision energies, and the collected information was imported into the PCDL software to form a Q-TOF/MS database. By comparing the retention time, primary mass spectrometry and secondary mass spectrometry information in melon and vegetable samples, determine whether the sample contains pesticide residues, and perform secondary confirmation on compounds with higher primary scores. If the secondary score is higher, it is confirmed Relevant pesticide residues were detected. The invention has the advantages of rapidity, high throughput, high precision, high reliability and the like, and can accurately screen pesticides in melons and vegetables.

The invention provides an LC-Q-TOF/MS detection technology for 544 pesticide residues in stem vegetables. The technology includes the steps of: 1) under a TOF/MS mode in the LC-Q-TOF/MS, respectively measuring retention time of each pesticide reference substance under the certain chromatography-mass spectrometry conditions; 2) determining the ionization formation and chemical formula of the compound with an ESI source to obtain accurate mass number of a parent ion of each compound to form a TOF/MS database; 3) under a Q-TOF/MS mode, respectively collecting fragment ion mass spectrograms under 3-5 different collision energy of each pesticide reference substance, and introducing the collected information to PCDL software to obtain a Q-TOF/MS database; 4)comparing the retention time, primary mass spectrum and secondary mass spectrum of the sample of the stem vegetables to determine whether the pesticide residues exist in the sample or not, and meanwhile, performing secondary determination to the compound having higher primary score, and if secondary score is high, determining existence of the pesticide residues. The technology is quick, high-throughput, high-precision and high-reliability, and can be used for accurately screening the pesticides in the stem vegetables.

The invention discloses a method for detecting ethyl urethane content of cigarette sidestream smoke via LC-MS/MS combination. A fishtail hood and a glass fiber filter disc are utilized to collect ethyl urethane of cigarette sidestream smoke; ethanol is applied to extraction of the glass fiber filter disc and cleaning of the fishtail hood; and an extraction liquid is diluted and then purified by a solid phase extraction small column, and finally eluted via dichloromethane, an eluant is detected by an efficient liquid chromatogram/tandom mass spectrometer, and the content of the ethyl carbamate of the cigarette side flow smoke. The method is simple and convenient to operate, has a good separation effect and accurate determination, and is short in sample analysis time and high in detection sensitivity.

The invention belongs to the technical field of material analysis, and provides a method for detecting amantadine compounds and triazine herbicides in algae. According to the method, acetonitrile, ethyl acetate, a formic acid-acetonitrile mixed solution with the formic acid volume concentration of 1% or a formic acid-ethyl acetate mixed solution with the formic acid volume concentration of 1% are adopted as an extracting agent, so that amantadine compounds and triazine herbicides in an algae sample can be released; a PSA adsorbent is used as an adsorbent; impurities which have great interference on amantadine compounds and triazine herbicides in an extracting solution can be adsorbed and removed to the greatest extent, qualitative detection is performed by adopting ultrahigh performance liquid chromatography, primary mass spectrometry and secondary mass spectrometry, the qualitative accuracy can be improved, false positive can be eliminated, and the detection accuracy can be improved; the amantadine compounds and the triazine herbicides can be accurately quantified by performing quantitative analysis on the amantadine compounds and the triazine herbicides by using ultrahigh liquid chromatography and primary chromatography, and the method has relatively high detection sensitivity.

The invention discloses a method for detecting urotropin in cigarette mainstream smoke through gas chromatography-tandem mass spectrum. The method comprises the steps of gathering mainstream smoke total particulate matter of 20 cigarettes according to the rule of ISO4387:2000, then putting a cambridge filter with the mainstream smoke total particulate matter into a 250mL bread bottle, adding 40 mL of ethanol extract liquor containing triethylamine to oscillate for extracting the cambridge filter for 40 minutes, accurately taking out 20mL of the extract liquor to pass through an activated silica gel columella, washing the columella by using 30ml of dichloromethane firstly, dropping leacheate, then washing the columella by using 40mL of methyl alcohol, collecting the leacheate to concentrate to 1mL, accurately adding 50 microliters of 10mg/L internal standard solution to detect by using GC-MS/MS (Gas Chromatography-Mass Spectrometry/ Mass Spectrometry). According to the method, the GC-MS/MS is used for detecting the urotropin in the cigarette side stream smoke; a multi-reaction monitoring mode is adopted for determining the nature; the method is capable of effectively improving the qualitative accuracy and sensitivity of the method, suitable for the detection of urotropin in various types of cigarette side stream smoke, wide in application and capable of accurately detecting; meanwhile, the method is simple, environment-friendly, and good in practicability.

The invention relates to a method for detecting four nitrosoamino acids (including NSAR, NAzCA, NMPA and NMBA) in buccal cigarette by liquid chromatography-tandem mass spectrometry. The method is characterized by comprising the following steps: carrying out vortex extraction on a buccal cigarette sample by adopting deionized water, adding a supernatant into a diatomite solid-phase support liquid-liquid extraction column, performing eluting by using an organic solvent, a collecting eluent, concentrating until the eluent is dry, performing redissolving by using deionized water, and finally performing analyzing by using a liquid chromatography-tandem mass spectrometer (LC-MS/MS). The method has the outstanding advantages that the sample does not need derivatization treatment, the pretreatmentis relatively simple, the accuracy is high, the sensitivity is high, the precision is good, the adding standard recovery rate is high, and the method is suitable for analyzing large-batch samples. Simultaneous detection of four nitrosoamino acids of various buccal cigarettes can be realized.

The invention belongs to the field of detection technology of levofloxacin, and discloses a quantitative detection method of levofloxacin in plasma. The method comprises the following steps: weighinglevofloxacin reference substance and levofloxacin-d8, diluting the levofloxacin reference substance and the levofloxacin-d8 with methanol and a methanol aqueous solution to obtain a series of levofloxacin working solutions and internal standard working solutions; pretreating a plasma sample by using the internal standard working solutions and a methanol precipitant, and performing LC-MS/MS analysis; preparing a series of correction guide samples and accompanying quality control samples by using blank plasma and the series of levofloxacin working solutions, then respectively performing LC-MS/MSmeasurement, using a chromatographic peak area ratio of the levofloxacin and the internal standard levofloxacin-d8 as a vertical coordinate, using the concentration of levofloxacin in the plasma as an abscissa to make a standard curve, and calculating the concentration of the levofloxacin in the plasma sample. The quantitative detection method disclosed by the invention has the advantages that measurement is performed via precipitation pretreatment and an LC-MS/MS mass spectrometer, so that the operation is quick and simple, the separation effect is good, the qualitative determination is accurate, and the detection sensitivity is high.