642 results about "Liquid chromatography–mass spectrometry" patented technology

Nonlinear retention time variations in chromatography-mass spectrometry data sets are adjusted by time-alignment methods, enabling automated comparison of spectra for differential phenotyping and other applications.

An automatic peak selection method for multidimensional data that selects peaks from very noisy data such as two-dimensional liquid chromatography-mass spectrometry (LC-MS) data is described. Such data are characterized by non-normally distributed noise that varies in different dimensions. The method computes local noise thresholds for each one-dimensional component of the data. Each point has a local noise threshold applied to it for each dimension of the data set, and a point is selected as a candidate peak only if its value exceeds all of the applied local noise thresholds. Contiguous candidate peaks are clustered into actual peaks. The method is preferably implemented as part of a high-throughput platform for analyzing complex biological mixtures.

The invention discloses a method for simultaneous extraction and analysis of a metabolite group and a lipid group in microtissue. The method comprises the following steps: freeze drying to-be-analyzed microtissue, accurately weighing 1 to 25 mg of the freeze-dried microtissue and adding solvents like methanol (MeOH), methyl tert butyl ether (MTBE) and water in certain proportion for extraction; allowing a solution obtained after completion of extraction to be divided into two layers, wherein an upper layer mainly contains nonpolar metabolites and lipids, and the lower layer mainly comprises polar and medium-polar metabolites; and subjecting the upper-layer solution and the lower-layer solution to mixing in proportion and freeze-drying, then carrying out redissolving and then metabonomical analysis based on liquid chromatography-mass spectrometry, subjecting the upper-layer solution to freeze-drying and then to redissolving and carrying out lipidomical analysis based on liquid chromatography-mass spectrometry. The method has the following advantages: metabolites and lipids are extracted as many as possible through one extraction of a small amount of tissue, and through metabonomical and lipidomical analysis, the amount of a tissue sample is saved, which benefits other biochemical analysis of the tissue sample.

The invention discloses a method for screening malignant ovarian tumor markers according to blood serum metabolic profiling. In the method, the Ultra Performance Liquid Chromatography-mass spectrometry technology is employed to analyze blood serum to obtain blood serum metabolic profiling; then the multivariate statistics method is employed to analyze data concerning malignant ovarian tumor and blood serum metabolic profiling of healthy people, so as to screen maker spectrums. The screening method of the invention features good repeatability and good forecasting property of the screened markers. Proven by discriminant classification analysis, the screening method enjoys an average forecasting precision rate of 90.90% and a positive relevance ratio of 82.65%.The maker spectrum covering multiple compounds can be obtained in a single analysis, which indicates that the marker is suitable for high flux analysis and enjoys the prospect of being promoted to large-scale sample screening and clinical application.

The invention discloses a method and kit for simultaneously measuring 35 kinds of psychotropic drugs by liquid chromatography-mass spectrometry. By optimizing chromatographic conditions and mass spectrometry conditions, the 35 kinds of psychotropic drugs can be simultaneously treated, the pretreatment step of the psychotropic drugs is simple, and protein precipitation is conducted simply through methanol. Compared with the prior art, the kit and the corresponding detection method have the advantages that the cost is greatly reduced, the analysis time is greatly shortened, the sensitivity is improved, the flux is increased, and the needs for clinical detection are met.

The invention provides a bladder cancer patient urine specific metabolite spectrum, an establishing method and an application, and especially provides a method for establishing a spectrum of specific metabolites in urine of bladder cancer patients, and a method for screening a related specific biomarker. Through metabonomics, especially metabonomics based on liquid chromatography-mass spectrometry combined technology, the invention establishes a bladder cancer patient urine specific metabolite spectrum. The invention provides a basis for early diagnosis of bladder cancer and bladder cancer diseases with different pathological stages, and also provides a spectrum of specific metabolites in urine of bladder cancer patients and a related specific biomarker. The method provided by the invention has the characteristics of noninvasiveness, convenience, and rapidness, can accurately reflect the difference of metabolite spectra of bladder cancer patients and normal people, and has high specificity.

The invention relates to a method for detecting oligosaccharides in breast milk. The method includes a step of breast milk sample pretreatment, namely taking a breast milk sample, centrifugally removing upper fat, taking lower liquid, adding alcohol solvent, freezing for 5-15min at a temperature ranging from -40 DEG C to -100 DEG C, centrifuging and taking supernatant. The invention further provides a method for qualitative and quantitative detection of oligosaccharides in the pretreated breast milk according to a liquid chromatography-mass spectrometry method. The method for simultaneous detection of various oligosaccharides in non-reducing breast milk by liquid chromatography-mass spectrometry is established and has advantages of effectiveness, quickness and simplicity in pretreatment. AQ Exactive detector is adopted for mass spectrometry, liquid-phase gradient elution parameters and mass spectrometric detection parameters are determined, ion information of non-reducing breast milkoligosaccharides in mass spectrometric detection under a positive ion mode is given, and the method can be well applied to qualitative and quantitative detection of the oligosaccharides in the breastmilk.

An adjustable, low mass-to-charge (m/z) filter is disclosed employing electrospray ionization to block ions associated with unwanted low m/z species from entering the mass spectrometer and contributing their space charge to down-stream ion accumulation steps. The low-mass filter is made by using an adjustable potential energy barrier from the conductance limiting terminal electrode of an electrodynamic ion funnel, which prohibits species with higher ion mobilities from being transmitted. The filter provides a linear voltage adjustment of low-mass filtering from m/z values from about 50 to about 500. Mass filtering above m/z 500 can also be performed; however, higher m/z species are attenuated. The mass filter was evaluated with a liquid chromatography-mass spectrometry analysis of an albumin tryptic digest and resulted in the ability to block low-mass, “background” ions which account for 40-70% of the total ion current from the ESI source during peak elution.

The invention discloses a method of establishing liquid chromatography-mass spectrometry (LC-MS) analysis of a royal jelly sensitized protein. The method comprises the following steps: carrying out electrophoresis analysis on royal jelly proteins, preprocessing the sensitized protein bands, analyzing sensitized protein bands by LC-MS, screening the specific peptide fragments of sensitized proteins; extracting proteins from a royal jelly sample, digesting the proteins by enzymes, and quantitatively measuring the sensitized proteins by LC-MS/MS. The provided sensitized protein quantitative method has the advantages of high specificity and sensitivity, good repeatability, high accuracy, and wide linear range, and is capable of precisely and quantitatively analyzing a sensitized protein in a sample.

The present invention discloses a method for enriching clenbuterol, ractopamine and salbutamol in a urine sample of breeding livestock, and relates to the field of analytical chemistry, particularly to a sample pretreatment method. The method comprises: carrying out a sample pretreatment, adding sulfonic group surface-modified polystyrene superparamagnetic nanometer beads or sub-micron beads to adsorb, carrying out elution, and collecting the eluent, wherein the elution solution can be directly used for liquid chromatography-mass spectrometry to quantitatively analyze contents of clenbuterol, ractopamine and salbutamol. The method has characteristics of simple operation process, high extraction recovery rate, less elution solvent use amount, and no requirement of rotary evaporation.

The invention relates to a detection method for simultaneously measuring the residue of tetracyclines (TCs) drugs in royal jelly, in particular to a detection method for simultaneously measuring the residue of 10 veterinary drugs including oxytetracycline, tetracycline, demethylchlortetracycline, chlorotetracycline, doxycycline, 4- epioxytetracycline, 4-epitetracycline, 4-epichlorotetracycline, minocycline and methacycline. The method comprises the following steps: precipitating protein by methanol; then, adjusting the pH value; further carrying out multi-stage purification; and simply and simultaneously measuring the residue of the TCs drugs by the liquid chromatography-mass spectrometry/mass spectrometer (LC-MS/MS). By carrying out the pre-treatment for one time, the invention can measure the residue of up to 10 TCs drugs in the royal jelly, wherein, the lower limits of detection (LLD) of the five TC antibiotics including oxytetracycline, tetracycline, demethylchlortetracycline, chlorotetracycline and doxycycline are 2.0 mug/kg; while the LLDs of the other veterinary drugs including 4- epioxytetracycline, 4-epitetracycline, 4-epichlorotetracycline, minocycline and methacycline are 10.0 mug/kg.

The invention discloses a method for analyzing amine substances in dansyl chloride derived-plasma based on liquid chromatography mass spectrometry. The method is characterized in that dansyl chloride is used as a derivatization reagent to perform derivatization on a metabolite containing primary amine and secondary amine, therefore the retention capability of the amine substances in reversion phase chromatography is increased, the ionization efficiency in mass spectrometric detection is increased, and the purpose of increasing the quantitative accuracy and detection sensitivity of the amine substances is achieved. The method has wide coverage for amine metabolites (comprising amino acid, methylation products, acetylation products, dipeptide and the like), can utilize 100 [mu]L of plasma samples to detect 113 amine substances, supplies the outline information of metabolome of the amine substances, and has the characteristics of good specificity, high accuracy and repeatability, less reagent consumption and the like.

The invention provides a method for synchronous detection of multiple residual drugs in a water environment, and belongs to the technical field of pollutant enrichment detection in a water environment. The residual drugs include antibiotics, anti-inflammatory analgesics and antihypertensive drugs, etc., and the synchronous detection method includes the following steps: (1) water sample pretreatment: filter to remove suspended matter, adjust the pH value of the water sample; (2) solidify Phase extraction: use HLB solid-phase extraction column to enrich the target drug; (3) blow nitrogen to nearly dry, dilute to 1mL and vortex for testing; (4) use LC-MS/MS for detection on the machine. The synchronous detection method of the present invention can simultaneously detect 32 pharmaceutical pollutants in the water body by one-time sample injection, and the method has the advantages of high accuracy and sensitivity and low detection limit; meanwhile, the method is environmentally friendly and easy to operate.

The invention relates to a method for detecting 153 pesticide residues in a heart benefiting and pulse restoring particle. The method is a liquid chromatography-mass spectrometry method. The method comprises the following steps: preparing a sample solution, preparing a matrix mixed reference substance working solution, and detecting the solutions through using the high performance liquid chromatography-mass spectrometry, wherein the sample solution is prepared through the following steps: crushing the heart benefiting and pulse restoring particle, weighing 1.8-2.2 g of the heart benefiting and pulse restoring particle, adding 80-120 [mu]L of an internal standard solution with the concentration of 5 [mu]g/mL, adding 8-12 mL of water, infiltrating the particle for 28-32 min, adding 8-12 mL of an acetonitrile solution containing 0.08-0.12% of acetic acid, oscillating the obtained solution in a swirl mixing oscillator at a rate of 4000-6000 r/min for 1.8-2.2 min, adding 3-5 g of anhydrous magnesium sulfate and 0.08-1.2 g of sodium acetate, carrying out swirl shaking for 4-6 min, centrifuging the obtained solution at a speed of 4000-6000 r/min for 4-6 min, taking 0.8-1.2 mL of the obtained supernatant, adding the supernatant to a centrifuging tube which is filled with 140-460 mg of anhydrous sodium sulfate, 23-27 mg of PSA, 48-52 mg of C18 and 2.3-2.7 mg of GCB in advance, carrying out swirl shaking for 2-4 min, centrifuging the obtained solution at a rate of 4000-6000 r/min for 4-6 min, taking the obtained supernatant, and filtering the supernatant by a 0.2-0.24 [mu]m filter membrane.

The invention discloses a method for simultaneously detecting six types of 24 antibiotics in livestock excrements by combination of ultrasonic extraction-solid phase extraction pretreatment and a liquid chromatography-mass spectrometry technology. The method comprises the following steps: (1) adding an internal standard substance for indicating the recycling rate in advance, and performing ultrasonic extraction; (2) performing solid phase extraction to enrich and purify target antibiotics; (3) performing the liquid chromatography-mass spectrometry technology to detect the contents of the 24 antibiotics. According to the method, the residue conditions of the six types of 24 antibiotics in the livestock excrements can be simultaneously detected at one time; the time of the detection processis short, the detection precision is high, the sensitivity, the stability and the selectivity are high, and the detection limit is low; by optimization of an extraction solvent, chelation between theantibiotics and metal ions in the excrements can be effectively reduced, so that the target antibiotics are separated from a sample, and the recycling rate is increased; furthermore, the method is easy and convenient to operate, high in enrichment factor and high in repetitiveness. The internal standard substance for indicating the recycling rate is added before the whole pretreatment process, sothat the loss of target substances in the pretreatment process can be well expressed, and a final result is more real and reliable.

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 present invention relates to a method for determining 10 kinds of antibiotics in a water environment through combination of a sample pre-treatment technology and HPLC-MS, and belongs to the field of detection of safety of trace organic contaminant residue in the water environment. The method is characterized in that a water sample is separated and enriched through combination of solid phase extraction and dispersive liquid-liquid microextraction (SPE-DLLME), and then an ultra-high performance liquid chromatography-mass spectrometry instrument (UPLC-MS/MS) is adopted as a detection tool to directly determine the contents of 10 kinds of common antibiotics in the water environment (drinking water, tap water, river water, sewage treatment plant influent and effluent), wherein the 10 kinds of the common antibiotics respectively are sulfadiazine, sulfamethoxazole, oxytetracycline, tetracycline, doxycycline, ciprofloxacin, levofloxacin, chloramphenicol, cefuroxime axetil and tinidazole. According to the present invention, the water sample pre-treatment method and the instrument detection conditions are investigated and optimized, and the optimal SPE-DLLME-UPLC-MS/MS method is established and is successfully applied for the real sample determination; and compared with the traditional method, the method of the present invention has advantages of high sensitivity, high extraction recovery rate, wide application objects, environmental protection, and the like.

The invention discloses a liquid chromatography-mass spectrometry screening method of unknown toxic substances in blood. The liquid chromatography-mass spectrometry screening method comprises the following steps: taking a blood sample to be detected, adding acetonitrile precipitated protein, oscillating, centrifuging, taking a supernatant, filtering by using a 0.22-micron microporous organic filter membrane, then performing LC-MS/MS analysis, and judging whether the blood sample to be detected contains toxic substance components or not according to an analysis result; the used instrument is an ultraLC 100-XL-4000Q TRAP liquid chromatograph/mass spectrometer or an Agilent 1100 liquid chromatography-AB 3200 QTRAP triple serial quadrupole mass spectrometer from an AB company. By the liquid chromatography-mass spectrometry screening method, detection methods of different types of toxic substances are established, detection is fast and accurate, the detection limits of common toxic substances are given, high-sensitivity and effective detection of all target objects are guaranteed, a scientific data support is provided for a negative detection result, and thus a strong scientific basis is provided for relevant clinical diagnosis and rescue as well as criminal investigation and litigation.

The invention discloses a method for detecting alkaloids and nitrosamines in tobaccos simultaneously, and belongs to the technical field of tobacco chemical composition detection. The method comprises the working procedures of: sample extraction, purification, analysis and quantification. Firstly an internal standard solution and ultrapure water are added into tobacco leaf powder, extract liquor passes through a filter film after ultrasonic extraction, then methanol is added, protein is removed through centrifugation after shaking, and supernatant is subjected to liquid chromatography-mass spectrometry. After standard solutions of compounds to be detected with different concentration gradients are prepared by adopting a mixing preparation method, and the liquid chromatography-mass spectrometry is carried out, standard curves of instrument responses of the compounds to the actual concentrations of the solutions are drawn, curve equations are fitted, and the detection concentrations are calculated according to measured values of the instrument responses of the compounds to be detected and converted to the actual concentrations of the compounds to be detected in tobacco samples. The detection method provided by the invention can be used for carrying out the qualitative and quantitative analysis on alkaloids and nitrosamines in the tobacco samples simultaneously, and is easy and convenient to operate, good in reproducibility, high in analytic sensitivity and accurate in quantification.

The invention discloses a high performance liquid chromatography mass spectrometry detecting method of 16 fat soluble saxitoxins in shellfish meet. The detecting method comprises the following steps of: processing a sample, purifying, testing the condition, qualitatively testing and quantitatively testing. According to the detecting method, methanol is adopted for extraction and a solid phase extraction column is adopted for purification so as to carry out the synchronous detection on the 16 fat soluble saxitoxins in the shellfish meet. The method is simple and convenient to operate, good in a purification effect, high in overall recycling rate and strong in reconstruction capability, and meanwhile an organic solvent and the processing time are saved, and the pretreatment process of the sample is simplified.

The invention relates to a method for separation enrichment and detection of trace fluoroquinolone antibiotic residues in a water environment. According to the method, 2.0-4.0L of a water sample is subjected to solid-phase extraction, and then analysis and detection are carried out by a liquid chromatography-mass spectrometry instrument. Being able to well separate and detect a plurality of fluoroquinolone antibiotic substances, the invention has the advantages of low detection limit, high recovery rate, high sensitivity, good selectivity and simple operation, etc., and has substantial effects in the detection study of trace fluoroquinolone antibiotic substances in the water environment.