8610 results about "Hplc mass spectrometry" patented technology

A high performance liquid chromatography system employs a nebulizer with a flow restriction at the exit of its mixing chamber to produce finer droplets, and an adjustable impactor for increased control over droplet sizes. Downstream of the mixing chamber, the nebulizer can incorporate tubing that is permeable to the sample liquid, to promote aerosol drying through perevaporation. A condensation particle counter downstream of the nebulizer uses water as the working medium, and is adjustable to control threshold nucleation sizes and droplet growth rates. A particle size selector employing diffusion, electrostatic attraction or selection based on electrical mobility, is advantageously positioned between the nebulizer and the CPC.

An apparatus to separate and analyze components of a liquid sample include a high performance liquid chromatograph with a mass spectrometer utilizing desorption electrospray ionization. This permits separation and evaluation of different components in a liquid sample. Further, this can be combined with online derivation via reactive DESI and, further, can be used with further electrochemistry.

The invention provides a method for simultaneously determining one hundred pesticide residuals in a traditional Chinese medicine through ultrahigh performance liquid chromatography-tandem quadrupole mass spectrum. The method comprises the following steps: immersing traditional Chinese medicine powder with ultrapure water, extracting with acetonitrile containing 0.1% acetic acid through a homogenate method, carrying out solid phase dispersing purification with N-propylethylenediamine and graphitized carbon, detecting in a timesharing multi-reaction monitoring mode through the ultrahigh performance liquid chromatography-tandem quadrupole mass spectrum, and quantifying with an external standard curve method. 88% of pesticides have good linear relations in a range of 5-500ng/mL, correlation coefficients are above 0.99, and the correlation coefficients of above 98% of the pesticides are above 0.97; the average recovery rate of the pesticides with the low concentration of 10mug/kg, the middle concentration of 50mug/kg and the high concentration of 100mug/kg is 70-130%, and the relative standard deviation is less than 0.15; and the detection limit is equal to or less than 0.01mg/kg, so routine detection requirements can be completely satisfied. The method has the advantages of strong versatility, good selectivity, high sensitivity, and rapidness and simplicity.

The present invention relates to a method and accompanying device for separating a known or unknown sample into one or more subsamples. By comparing the subsample's measurement profile data to the sample measurement profile data, the performance of the separation can be determined. The separation could be chromatography [such as high-performance liquid chromatography (HPLC), gas chromatography (GC), or the like], electrophoresis [such as capillary electrophoresis (CE) or the like], or another separation technique. The measurement profile data could be ultraviolet/visible (UV/Vis) spectra, mass spectra (MS), or another measurement technique.

The current invention provides compositions, which are useful as stationary phases for a variety of chromatographic applications, such as high performance liquid chromatography (HPLC). The compositions include a substrate (e.g., silica gel), covalently bound to a compound, which includes both a hydrophobic moiety and a hydrophilic moiety, which is preferably a 1,2-diol moiety. The hydrophobic moiety is sufficiently hydrophobic for the compositions to exhibit reversed phase characteristics and typically incorporates at least 5 carbon atoms in sequence. Based on having both hydrophilic and hydrophobic functionalities, the new stationary phases exhibit unique chromatographic properties. For example, these media can be used in either hydrophilic (HILIC) mode, in which the mobile phase includes a high percentage of an organic solvent, or in reversed phase mode, in which the mobile phase contains a higher percentage of an aqueous solvent. The current invention also provides methods of making and using the compounds and compositions of the invention.

The invention discloses a cyclodextrin chiral stationary phase, the structure of which is shown in the general formula (I), wherein X is -OCH3 or -OCH2CH3, n is equal to 1-7, and R is -H, -CH3, -COCH3, -COC6H5 and -CONHC6H5. The preparation method of the stationary phase comprises the following steps: a silane coupling agent, sodium azide and a catalyst are added into an organic solvent, then spheroidal silicon is added for preparing azide silica gel derivant; oligomeric ethylene glycol, sodium hydride and propargyl bromide are added into tetrahydrofuran for preparing bialkynyl oligomeric ethylene glycol; monosubstituted nascent and derivative cyclodextrin containing azid groups is prepared; finally, the click chemistry reaction method is used for bonding the cyclodextrin. The cyclodextrin chiral stationary phase has the advantages that the selectivity of the bonding reaction is high, and the surface bonded amount is large; the chiral separation ability is strong, thereby being especially suitable for the chiral separation of a high efficiency liquid chromatography in the reversed-phase mode; the preparation method is simple and has less steps, the bonding reaction is the click chemistry reaction, the reaction condition is mild, and the reaction is carried out in the water solution.

The invention discloses a method for controlling the quality of ginkgo leaves and an extract thereof. After the screening of a great quantity of experiments, the method adopts ultra-high performance liquid chromatography for detection; and the method can be used for detecting three types of components including flavone, terpene lactones and phenolic acid, twenty-four active compounds in total, in the ginkgo leaves and the extract of the ginkgo leaves. The results of the experiments prove that the method is high in detection sensitivity and good in stability, and can be used for objectively, comprehensively and accurately evaluating the quality of ginkgo leaf medicines, the extract of the ginkgo leaves and ginkgo leaf preparations, thus having important significance on controlling the quality and guaranteeing the clinical treatment effect.

The invention relates to a method for measuring tobacco-specific nitrosamines (TSNAs for short) by using a super efficient liquid chromatogram-tandem mass spectrum combined method, and belongs to a method for detecting TSNAs. The method comprises the following steps of: adding internal standard-containing aqueous solution of ammonium acetate into a filter sheet after trapping smoke and cigarette filters smoked completely under standard conditions or tobacco shreds, performing ultrasonic extraction, transferring 1 to 2mL of extract into a small solid-phase extraction column taking N-vinyl pyrrolidone-benzene sulfonic acid copolymer as filler, flushing the small column by using aqueous solution of methanoic acid and methanol, finally eluting the small column by using solution of aqueous ammonia and methanol solution, analyzing the eluant by using an ultra performance liquid chromatography-mass spectrometer/mass spectrometer (UPLC-MS/MS), and quantifying according to the area ratio of a component peak to an isotope internal standard peak. The detecting method can be used for detecting the TSNAs in cured and hybrid cigarette mainstream smoke, cigarette side-stream smoke, filter tip intercepting smoke and tobacco shreds, and has the advantages of simple pretreatment, accurate quantification, high instrument analysis speed, low detection limit, high sample treatment flux and the like.

The invention discloses a method for determining content of volatile carbonyl compound in main stream smoke of cigarette. 2, 4-dinitrophenylhydrazine is utilized to gather volatile carbonyl compound in main stream smoke of cigarette, so as to form hydrazone compound, and the content of the hydrazone compound is determined by a high performance liquid chromatograph by adopting external standard method; and the high performance liquid chromatograph adopts chromatographic column. The determination method of the invention adopts chromatographic column, has excellent separating effect on nitro substituted arene derivative, especially on hydrazone compound formed after reaction of 2, 4-dinitrophenylhydrazine and volatile carbonyl compound, and meanwhile chromatographic analysis condition is optimized, thus achieving complete separation of volatile carbonyl compound and interfering component in main stream smoke of cigarette and improving accuracy of determination.

The invention relates to the separation of antibiotic and the application of the antibiotic in resisting infectious diseases, in particular to an isovaleryl-spiramycin I single-component compound. A kelimycin sample is separated by HPLC (high performance liquid chromatography) after crude separation, high-efficiency purification and post-processing, so as to obtain the pure isovaleryl-spiramycin I compound. Biological experiment results show that the antibacterial activity of the isovaleryl-spiramycin II compound is better than that of kelimycin and is much better than that of a control group. The invention lays the foundation for developing the clinical and effective isovaleryl-spiramycin II single-component antibiotic.

Extracts prepared from red and high-pigment beetroots (Beta vulgaris L.) with a solvent, such as a water-containing solvent, possess antioxidant activity as demonstrated by a panel of assays. These extracts also have an ability to induce quinone reductase in Murine hepatoma cell (Hepa 1c1c7) cultured in vitro. Fractions purified from the active extracts also possess antioxidant activity and retain quinone reductase-inducing activity in the Hepa 1c1c7 cell line. The active extracts, purified by column, thin layer, and high-performance liquid chromatographic techniques, include betalains. A method of extracting a betalain includes steps of freeze-drying a source containing the betalain; grinding the freeze-dried source; and extracting the betalain from the ground source with the solvent. Additionally, the betalain extract can be isolated betalain components, such as by chromatography.

The object of the present invention is a fluoropolymer aqueous dispersion showing only a moderate viscosity increase upon temperature rise and having a low fluorine-containing anionic surfactant concentration as well as a method of producing such fluoropolymer aqueous dispersion. The present invention provides a fluoropolymer aqueous dispersion comprising a particle comprising a fluoropolymer dispersed in an aqueous medium in the presence of a nonionic surfactant, wherein a supernatant for assaying as obtained by subjecting the fluoropolymer aqueous dispersion to 30 minutes of centrifugation at 25° C. and at a gravitational acceleration of 1677 G, when subjected to high-performance liquid chromatography [HPLC] under the conditions of a flow rate of 1.0 ml/minute and a column temperature of 40° C. using an acetonitrile/0.05 M aqueous solution of phosphoric acid (60/40% by volume) mixture as a developing solution, followed by detection at an absorption wavelength at which the nonionic surfactant can be identified, shows a ratio (A¹/A⁰), which is the ratio between the total area (A⁰) under the detected line and the area (A¹) under the detected line over a retention time period shorter than 16 minutes, of not lower than 0.4 and the supernatant for assaying has a fluorine-containing anionic surfactant content of not higher than 100 ppm.

The invention discloses a general rapid detection method for micromolecular poisonous and harmful substances in liquid milk. The method is characterized in that the method concretely comprises the following steps: 1, carrying out simple and general extraction and purification on a liquid milk sample to obtain a loading liquid; 2, preparing a mixed standard solution and a matrix addition standard curve; 3, determining the micromolecular poisonous and harmful substances in the liquid milk through UPLC-MS/MS; and 4, carrying out concentration calculation. The method of the invention has the following advantages: the method starts from general characteristics of micromolecular compounds and fully takes the dissolvability, the thermal stability, the acidic and basic stability, the polar strength, the coexistent stability and the like of all the substances into consideration, a general rapid preprocessing technology and a UPLC-MS/MS electro-spray apparatus determination technology are developed, and the substantial efficiency improvement and the detection cost reduction effect are brought to the production process control and food detection work on condition that detection limit requirements are satisfied.

The invention discloses a high-throughput detection method for 99 residual veterinary drugs in animal-derived food. The detection method is characterized by comprising the following concrete steps: (1) carrying out extraction and purification on 99 residual veterinary drugs having substantially different physicochemical properties and belonging to eight kinds of common veterinary drugs through one-step pretreatment based on carrier-assisted liquid-liquid extraction technology; (2) preparation of a mixed standard solution and a matrix standard curve; and (3) determining the concentrations of 99 residual veterinary drugs in a to-be-detected solution by using ultrahigh performance liquid chromatography-triple quadrupole tandem mass spectrometry. According to the invention, the pretreatment and instrumental analysis process of the method is directed at compounds with different physicochemical properties, so the method has the advantages of good compatibility, high detection efficiency, good operability and low detection cost, and the detection limit of the method can meet requirements of all the test objects.

The invention belongs to the field of food inspection, relates to an assay determination method for endocrine disruptors in food, and particularly relates to a method for analyzing and determining a plurality of endocrine disruptors in milk powder and liquid milk. The method comprises the steps of dissolving a sample with water, adding an organic solvent mixable with water, extracting a to-be-detected material by ultrasonic, adding a sodium salt to make the organic solvent separated from a water phase to realize liquid-liquid extraction, taking an organic solvent containing quantitative to-be-detected material, purifying by extraction with a solid phase filled with C 18 materials, deriving by dansyl chloride, and analyzing and detecting four types of 26 endocrine disruptors in the food by using ultra-high performance liquid chromatography-quadrupole-time of flight-mass spectrometry at the same time. The method can overcome the disadvantages that a conventional technology cannot realize simultaneous analysis of the plurality of the endocrine disruptors in the food by once chromatographic sample injection, can increase sensitivity of the quadrupole-time of the flight-mass spectrometry, and realize accurate analysis of the endocrine disruptors in the food by using the quadrupole-time of the flight-mass spectrometry.

The invention discloses a preparation method for fast separating flavonoid glycosides from oil-tea-cakes with a medium pressure column, which comprises the following steps of: decorticating and crushing camellia oleifera abel seeds, degreasing the camellia oleifera abel seeds with non-polar solvents, performing extraction with ethanol water, filtering and condensing the extract to obtain crude extract concrete, performing fast separation with the medium pressure column to obtain an over 90 percent flavonoid glycoside mixture, and further adopting a high performance liquid chromatography to prepare over 95 percent flavonoid glycoside monomers, wherein the flavonoid glycoside monomers are kaemplerol 3-O-[2-O-beta-D-galactose-6-O-alpha-L-rhamnose]-beta-D-glucoside (I) and kaemplerol 3-O-[2-O-beta-D-xylose-6-O-alpha-L-rhamnose]-beta-D-glucoside (II) respectively. The method can be used for batch preparation, and has the advantage of providing quality raw materials for the development of flavonoid glycoside medicaments and healthcare functional products in the oil-tea-cakes.