120results about How to "Improve Quantitative Accuracy" patented technology

The invention relates to a cigarette mainstream smoke on-line analysis device and a cigarette mainstream smoke on-line analysis method. The device comprises a smoking machine and an atmospheric pressure chemical ionization tandem mass spectrometer. The on-line analysis method comprises the steps that: when the cigarette is smoked, mainstream smoke is collected into a mainstream smoke collection bottle; the smoke sample is directly introduced into the atmospheric pressure chemical ionization tandem mass spectrometer through a feeding valve, and is subjected to fast analysis. Compared with a traditional cigarette mainstream smoke analysis method, the smoking machine and the sample collection and introduction device have the advantages of simple structure and convenient operation. The sampling bottle of the smoking machine is connected to an ion source of the mass spectrometer through a capillary, such that sample direct introduction can be realized. Only a few seconds are needed from cigarette smoking to feeding and analysis. The sensitivity is high, and repeatability is good. The method and the device are suitable for on-line analysis of organic compounds in single-suction and suction-by-suction cigarette mainstream smoke.

The invention provides a Taqman fluorescent hydrolysis probe and a method for quantitatively detecting the methylation level of MGMT (O6-methylguanine-DNA-methyltransferase) by using the Taqman hydrolysis probe. The fundamental sequence of the Taqman fluorescent hydrolysis probe is GATTTGGTGAGTGTUTGGG, and the complementary region of the fundamental sequence and a genomic DNA (deoxyribonucleic acid) sequence extends upstream no more than 5nt and extends downstream no more than 5nt. According to the invention, the specificity of PCR (polymerase chain reaction) is doubly guaranteed; the percent of a methylated DNA template in a mixed sample can be quantitatively calculated; and the method has all the advantages (such as speediness, sensitiveness, no pollution, and the like) of the real-time quantitative PCR. The application of detection results of the invention can provide clinical guide for medicaments for carrying out chemotherapy on malignant tumors such as cerebral gliomas and the like; and the method has the advantages of high specificity, high sensitivity, accurate quantification, and the like.

The invention relates to a method for quantificationally characterizing cell shape features of flue-cured tobacco leaves by utilizing Photoshop software, which is characterized by comprising the following steps of: obtaining a surface cell feature image of the preliminarily-flue-cured tobacco leaves through a scanning electron microscope, accurately selecting cells by utilizing a magnetic lasso, a matte, a paintbrush, an eraser and other tools, respectively and quantificationally obtaining the cell circumference and the cell area by using a unit pixel length*number of pixels and pixel percentage*image area method, calculating shape feature parameters through taking the circumference and the area as variables by utilizing a formula to provide a method for objectively evaluating the cell development situations of the tobacco leaves and researching the quality features of the tobacco leaves from the microscopic field. Measurement results of a plurality of cells randomly selected from different places of origin show that the method is high in accuracy and high in fitting degree of the calculated cell shape feature parameters with software-defined roundness values (R2 is equal to 0.98-0.99), and meanwhile, the cell shape features (quality features) of the tobacco leaves from the different places of origin can be better distinguished.

The invention provides a mass spectrometry detecting method for a serum polypeptides, comprising sample preparation, data-independent mass spectrometry acquisition, and data processing. According to the mass spectrometry detecting method for the serum polypeptides, a data-independent mass spectrometry acquisition method for serum peptidomics samples is developed, and the parent ion distribution ofthe sample by pre-analytical experiment on serum samples is obtained, thereby obtaining an optimal variable isolation window. Each condition and each step cooperate with each other by optimizing thepreparation method of the polypeptideomics sample, the mass spectrometry acquisition method, and the data processing method, and finally, the number of the detection of the polypeptide, the reproducibility of the identification, and the quantitative accuracy are significantly improved. The method of the invention has the characteristics of high throughput, high reproducibility, and high accuracy,and is suitable for analysis of large-scale clinical serum samples and detection of disease markers, thereby having wide application prospects and great market value.

The invention discloses a metabolism group method for distinguishing false positive mass spectra peak signals and quantificationally correcting mass spectra peak area. The invention provides a metabolism group study method; by the method, the biological source and non-biological source mass spectra peak signals can be effectively distinguished; the mass spectra peak signals are quantificationally evaluated; the mass spectra peaks with poor quantification performance are excluded; through QC sample dilution, a relative content correction model is built; the mass spectra peak area is corrected. The method has the maximum characteristics that the false positive mass spectra signals can be effectively eliminated, so that the metabolism group data becomes reliable; the real biomarkers can be favorably screened. The method can aim at plant, animal and microbe samples; the method can also be suitable for the mass-spectra-platform-based metabolism group analysis of GC-MS, LC-MS and CE-MS.

The invention relates to a method for determining the content of hydrocarbons and oxygen-containing compounds in Fischer-Tropsch synthetic oil. The method comprises the following steps: separating theFischer-Tropsch synthetic oil through a solid-phase extraction method to obtain a hydrocarbon mixed component and an oxygen-containing compound mixed component; carrying out gas chromatography-massspectrometry analysis, determining a reference component in an obtained spectrogram, calculating a retention index of each peak, determining hydrocarbons or oxygen-containing compounds corresponding to each peak according to the retention indexes and a compound qualitative database, and obtaining the content of each hydrocarbon or oxygen-containing compound according to the peak area. Compared with the prior art, according to the invention, the method has the advantages that rapid separation of hydrocarbons and oxygen-containing compounds in the Fischer-Tropsch synthetic oil is realized through a solid phase extraction method, mutual interference of hydrocarbons and oxygen-containing compounds in the Fischer-Tropsch synthetic oil in retention time is effectively eliminated through GC-MS, and rapid qualitative and quantitative analysis of each component is realized in combination with qualitative advantages of GC-MS and a simple data processing algorithm.

The invention discloses a detection method of free and combined carboxy methyl lysine in milk and dairy products. According to the detection method, isotope dilution high performance liquid chromatography- tandem ion trap mass spectrometry is adopted to detect free carboxy methyl lysine and carboxy methyl lysine combined with protein in milk and dairy products. According to the detection method, using of ion-pairing agent is avoided; no derivatization pretreatment is needed; efficiency, accuracy, sensitivity, and reproducibility are high; linearity range is wide; the detection method possesses unique features in analysis of the content of free carboxy methyl lysine and carboxy methyl lysine combined with protein in milk and dairy products, can be used for rapid and accurate qualitative and quantitative analysis on free carboxy methyl lysine and carboxy methyl lysine combined with protein in milk and dairy products, and can be used for detection of free and combined carboxy methyl lysine in milk and dairy products preferably.

The invention provides a method for detecting 7 classes of 59 forbidden drugs in goat milk and goat milk products. The method comprises the following steps: (1) sample pretreatment: extracting a to-be-detected sample with an acid organic solvent, carrying out purification by virtue of an SPE column, dissolving a purified liquid by virtue of a primary flow phase, and carrying out UPLC-MS/MS detection; and (2) detection of 59 to-be-detected forbidden drugs: detecting the pretreated sample by virtue of an ultra-high performance liquid chromatography-mass spectrometry under specified instrument conditions of the method. The method has the advantages that many drugs can be detected, the type of the drugs is rich, the detection time is short, the sensitivity is high, and a result is accurate andstable; and meanwhile, the detection blank that multiple types and quantity of drugs in the goat milk and the goat milk products can be simultaneously detected is filled up, and the method has important significances to the guarantee of the body health of consumers and the increase of export trade competitiveness of the goat milk and the goat milk products.

The invention relates to a gene detection probe, a primer and a kit for spinal muscular atrophy, wherein the gene detection probe for spinal muscular atrophy comprises a probe SMN1-7 for detecting a SMN1 gene, and the nucleotide sequence is shown in SEQ ID No. 1; a probe SMN2-7 for detecting a SMN2 gene, and the nucleotide sequence is shown in SEQ ID No. 2. According to the invention, a multiple fluorescence quantitative detection system with high specificity and low cost is established. High frequency pathogenic mutation detection of the SMN1 and SMN2 genes in one tube is realized. In addition, a multiple scorpion tail primer amplification system is established, so that the problem of the amplification consistency of the multiple fluorescence quantitative systems is solved, and the quantitative accuracy is improved.

The present invention discloses a method for authenticating an unsaturated lipid carbon-carbon double bond position based on epoxidation and a mass spectrum. The method comprises: performing epoxidation derivation on to-be-analyzed unsaturated lipid by using low-temperature plasma; performing tandem mass spectrum analysis on an epoxidation product that is obtained after the epoxidation derivationon the unsaturated lipid, to obtain a specific ion at the carbon-carbon double bond position; and authenticating the unsaturated lipid carbon-carbon double bond position according to the specific ion.The method is simple and practicable without transforming the mass spectrum. The epoxidation derivation of the low-temperature plasma is combined with the tandem mass spectrum, so that the carbon-carbon double bond position in the unsaturated lipid can be fast and accurately authenticated.

The invention provides a method for detecting 8 categories of restricted drugs in goat milk and products thereof, wherein the number of the restricted drugs is 74. The method comprises: (1) pre-treating a sample: extracting a sample to be detected with an acid organic solvent, purifying with a SPE column, and dissolving the purified liquid by using an initial mobile phase so as to be used for detection with UPLC-MS/MS; and (2) determining 74 restricted drugs: determining the pre-treated sample by using ultra performance liquid chromatography-LC-MS under the instrument condition specified by the method. According to the present invention, the method has advantages of more types of detected drugs, rich variety, short detection time, high sensitivity and accurate and stable results, can makesup for the absence of the simultaneous detection of multiple drugs in goat milk and dairy products, and provides the important significance for the assurance of the health body of consumers and the improvement of the export competitiveness of goat milk and dairy products.

The present invention relates to a kit. Said kit can use cDNA obtained by means of reverse transcription of mRNA sample as template, and combines it with real-time fluorescent PCR detection technique, so that it can be mainly used for determining expression level of epidermal growth factor receptor III type mutant mRNA in various tumor tissues.

The present invention relates to a multiple-sample multiple-target high-throughput accurate absolute quantification method of proteomes. A N-terminal and a lysine amino group of a peptide fragment canbe labeled by dimethylation reaction, and by organic combination of various isotopic forms of a dimethylation labeling reagent, multiple labeling of a to-be-tested protein and/or peptide fragment sample and a protein and/or peptide fragment in a target internal standard substance with a known amount can be realized. The labeled sample is analyzed by a LC/MS system. Peak areas of characteristic fragment ions in the secondary spectrum of the sample and the internal standard substance are extracted for quantifying to obtain the absolute amount of a target protein in the to-be-tested sample. Themethod has the advantages of high analysis throughput, great saving of analysis time, cheap labeling reagent, strong practical application, high quantitative accuracy, good precision, and wide dynamicrange, and can meet the needs of multiple-sample analysis based on the internal standard substance or multiple-target analysis based on a standard curve.

The invention relates to a fluorescent quantitative PCR detection kit and a detection method of HBV and TP of donor corneas. The kit comprises a DNA (deoxyribonucleic acid) extraction reagent, a DNA amplification reagent and positive working standards, wherein the DNA amplification reagent comprises a premix reagent, a 20X fluorescent probe reinforcing agent, forward and reverse HBV primers, an HBV fluorescent probe, forward and reverse TP primers, a TP fluorescent probe, distilled water of ribose-free nuclease and HBV and TP negative control and positive control; the positive working standards are pUC57-HBV plasmids containing destination sequences amplified by the forward and reverse HBV primers and a pUC57-TP plasmids containing destination sequences amplified by the forward and reverse TP primers. The invention realizes the complete closed-tube detection on donor conjunctiva tissue specimens and does not need PCR aftertreatment, and thereby, cross contamination is avoided; meanwhile, real-time detection is adopted, and an obtained Ct value and the original template number are completely in linear correlation; the quantitative accuracy rate is extremely high, and the relative error is about 50 percent, and thereby, the invention is enough to adapt to the demands of clinical nucleic acid quantification.

The invention discloses a high-sensitivity and high-accuracy method for simultaneously determining NNAL and cotinine in urine. The method comprises the following steps: 1) preparing a single standardstock solution containing the NNAL, the cotinine, isotope-labeled NNAL and isotope-labeled cotinine; 2) preparing mixed standard sample working solutions having a series of concentrations and containing the NNAL and the cotinine, and making a standard curve; 3) taking a to-be-determined urine sample, adding a phosphate buffer solution containing an isotope-labeled internal standard, and adding 15-25 [mu]L of beta-glucuronidase for enzymolysis; and 4) taking out the sample solution subjected to the enzymolysis, naturally cooling the sample solution into the room temperature, performing solid-phase extraction, performing instrument analysis, and performing calculation according to the standard curve made in the step 2) to obtain the content of the NNAL and the cotinine. The method effectively solves the problems of complex pretreatment and long consumed time of an existing method for simultaneously testing the NNAL and the cotinine in the urine; and meanwhile, the matrix effect in the urine is greatly reduced, so that the detection sensitivity and accuracy are improved.

The invention is applicable to the field of non-destructive testing, and provides a magnetic permitivity meter for magnetic flux leakage detection. The meter is internally provided with an excitationunit, and one or more magnetic sensors are disposed under the excitation unit. The magnetic sensors can measure the magnetic permitivity of a comparison template or an object to be inspected for laterquantitative evaluation of defects, and the scheme takes the magnetic property difference of the comparison template or the object to be inspected into consideration, is adapted to more objects to beinspected, and improves the quantitative accuracy of the defects.

The invention discloses a method for detecting N-nitrosodimethylamine in beer. The method comprises the followings steps: adding a D6-N-nitrosodimethylamine internal standard substance into a beer sample, adding sodium chloride to dissolve to saturation, extracting by using dichloromethane, concentrating extracting liquid, dissolving by cyclohexane, purifying dissolved liquid by an SILICA/PSA solid phase extraction column, eluting and collecting by dichloromethane, taking 1.01 [mu]l of a sample for feeding, and analyzing and detecting by a gas chromatograph-mass spectrometer, establishing a standard curve by using an internal standard method, detecting and calculating so as to obtain the content of N-nitrosodimethylamine in the beer. According to the method, after extraction by dichloromethane, the SILICA/PSA solid phase extraction column is adopted for purification, so that interfering substances are effectively removed, and interfering substance removal capacity is high. The gas chromatography-low-resolution mass-spectrometry is adopted for determining, so that requirements for the instrument are low, the cost is low, and the method is easy to popularize and use. According to the embodiment of the invention, under the condition that interfering ions 44 and 73 are added, a target object can be measured accurately, so that the fact that the method is high in reliability is indicated.