88 results about "Two-dimensional gas" patented technology

A two-dimensional gas chromatograph with a primary column (14) and dual secondary columns (26, 28) is described. Flow rates in the primary column are less than those in the secondary columns due to an accumulation valve (16). Typically the ratio of second and third column flow capacities combined to primary column flow capacities between about 10 to 1 and 30 to 1. Volatile organic compounds are detected in environmental samples of air water, soil and in body fluids of animals and humans.

The present invention relates to a device for separation and characterization of gas-phase ions. The device incorporates an ion source, a field asymmetric waveform ion mobility spectrometry (FAIMS) analyzer, an ion mobility spectrometry (IMS) drift tube, and an ion detector. In one aspect of the invention, FAIMS operating voltages are electrically floated on top of the IMS drift voltage. In the other aspect, the FAIMS/IMS interface is implemented employing an electrodynamic ion funnel, including in particular an hourglass ion funnel. The present invention improves the efficiency (peak capacity) and sensitivity of gas-phase separations; the online FAIMS/IMS coupling creates a fundamentally novel two-dimensional gas-phase separation technology with high peak capacity, specificity, and exceptional throughput.

A method of estimating contamination of oil based mud filtrate in a hydrocarbon sample. The method comprising the steps of obtaining a hydrocarbon sample contaminated with oil based mud filtrate, then analyzing the contaminated hydrocarbon sample using two-dimensional gas chromatography (GC×GC). The method further comprises identifying one or more unique component or tracer in the oil based mud filtrate in the contaminated hydrocarbon sample. Finally, the method comprises of summing the peak volumes of the one or more unique component or tracer, relative to the peak volumes of a clean hydrocarbon sample.

A light-emitting diode having a silicon substrate on which there are successively formed a buffer layer, a p-type nitride semiconductor layer, an active layer, an n-type nitride semiconductor layer, and a current spreading layer. The current spreading layer is a lamination of a first and a second sublayer arranged alternately a required number of times. Composed of different compound semiconductors, the alternating sublayers of the current spreading layer create heterojunctions for offering the two-dimensional gas effect. The current spreading layer is so low in resistivity in a direction parallel to its major surface from which light is emitted, that the current is favorably spread therein for improved efficiency of light emission. A front electrode in the form of a metal pad is mounted centrally on the major surface of the current spreading layer in ohmic contact therewith.

The invention discloses a GC*GC (comprehensive two-dimensional gas chromatography) method for hydrocarbons in crude oil or sedimentary organic matters. The method is implemented through directly carrying out analysis on crude oil or sedimentary organic matter samples by using GC*GC-FID (GC*GC-flame ionization detection) so as to obtain data of hydrocarbons (saturated hydrocarbons, aromatic hydrocarbons and the like); and by using GC*GC-TOFMS (GC*GC-time-off-flight mass spectrometer) software and methods and comprehensive two-dimensional gas chromatographic hydrocarbon separation characteristic determinations, carrying out calculation on the data so as to obtain the localization parameters of saturated hydrocarbons and aromatic hydrocarbons. The method disclosed by the invention is validated through taking the GC*GC on crude oil and sedimentary organic matter samples in the Saertu Oilfield in Daqing, the fangzheng fault depression of the peripheral basin, and the Hailer-Tamtsag Basin as examples. The GC*GC method for hydrocarbons in crude oil or sedimentary organic matters disclosed by the invention creates a new method for analyzing hydrocarbons in crude oil or sedimentary organic matters, and has important significances in deep understanding of the oil pool forming process, migration, accumulation, preservation, oil and source rock correlation of crude oil and the geochemical researches on oil pools, exploration of new geochemical indicators of crude oil and the exploration and development of crude oil.

Methods of determining the source of an unknown sample are disclosed. Mass spectra from possible sources are obtained using two-dimensional gas chromatography coupled with time-of-flight mass spectrometry. That data is processed to obtain a dataset. A random forest algorithm is used to classify the dataset and create a classifier that distinguishes between the possible sources.

The Invention is a method for quantitative analysis of a mixture of molecular compounds by two-dimensional gas chromatography having application for quantitative analysis of products from the chemical or petroleum industry. A two-dimensional gas chromatography is carried out, during which a chromatographic signal is recorded. A chromatogram in two dimensions on which chromatographic peaks form spots is generated from the signal. These spots are defined by means of polygons. Then, for each polygon, chromatographic signal portions contained between two intersections of the polygon with columns of the chromatogram are extracted. Start and end times are defined for the chromatographic peaks present in these portions and the polygon is adjusted by shifting its intersection points according to the start and end times of the chromatographic peaks. Finally, molecular compound amounts are determined by calculating the surface area of the polygons thus adjusted.

The invention discloses a composite quantum point device and a process for making it. The device includes a doping buffer layer made on the substrate using the high adulterated conductive GaAs in sequence by a molecular beam epitaxy method, semi-conductive GaAs isolating layer, an InAs quantum point layer and a thin GaAs cover layer covered on the InAs quantum point layer, an electrode prepared on the cover layer of the substrate and depositing AuGeNi on the back of the substrate as the back grid of the device, it also includes an AlGaAs/GaAs layer, a superlattice barrier layer prepared on the buffer layer and a theta -Si doping layer. The device is a composite quantum point device made by arrangement such as quantum points, two-dimensional gas and a thin Schottky barrier layer using the conventional method, it possesses a plurality of functions including luminescence, optical detection, amplification and storage.

The invention provides a comprehensive two-dimensional gas chromatography quantitative analysis method of an aromatic sterane compound in petroleum. The method comprises the following steps: fully dissolving and soaking crude oil with a solvent and then filtering to obtain a filtrate; heating to evaporate and concentrate the filtrate to prepare filtrate concentrate; collecting a saturated hydrocarbon group component and an aromatic group component; preparing a saturated hydrocarbon group component sample and an aromatic group component sample and storing the samples at low temperature; analyzing the two samples by using a comprehensive two-dimensional gas chromatograph and a flight time mass detector; performing data processing on spectrograms obtained in the steps to obtain corresponding retention time and peak area integration result. The analysis method can be used for performing full oil analysis and group component analysis; an orthogonal separation system thereof can completely separate the aromatic steroid hydrocarbons from alkane, so that the problems such as common rolling peak, base line interference and insufficient peak capacity can be excellently solved, and the aromatic sterane compound can be accurately measured.

The invention relates to the field of tobacco preparation and discloses a quality monitoring and control method for tobacco essence perfume. In the method, a traditional fingerprint technology, a two-dimensional gas chromatograph-mass spectrometer (GC-MS) and sensory smoking evaluation are organically combined, so that advantages of the three methods are combined together while the defects are complemented by each other, thereby achieving the object of effectively control the quality of the essence perfume. The method particularly includes the steps of: 1) collecting gas-phase chromatograph and fingerprint spectrum of the essence perfume; 2) obtaining information of a key fragrant component through the GC-MS and quantitatively weighting the information in the fingerprint spectrum; 3) finally quantizing experience of a smoking evaluation expert, and quantitatively adding the chemical components, which cannot be effectively detected by means of analysis instruments, to the fingerprint spectrum in manners of component simulation and weighting, thereby forming a holographic fingerprint spectrum with combination of multiple characters; 4) on the basis of the holographic fingerprint spectrum, establishing a fingerprint spectrum database of the target essence perfume and establishing a standard mode; and 5) through a statistic analysis method, performing quality monitoring and control of a new essence perfume sample or effective identification of a unknown sample. Compared with a conventional quality monitoring and control method, the method provides more abundant and comprehensive information and more accurate and reliable result. The method has wide application value and market prospect.

A monitoring test for recurrent breast cancer with a high degree of sensitivity and specificity is provided that detects the presence of a panel of multiplicity of biomarkers that were identified using metabolite profiling methods. The test is capable of detecting breast cancer recurrence about a years earlier than current available monitoring diagnostic tests. The panel of biomarkers is identified using a combination of nuclear magnetic resonance (NMR) and two dimensional gas chromatography-mass spectrometry (GC×GC-MS) to produce the metabolite profiles of serum samples. The NMR and GC×GC-MS data are analyzed by multivariate statistical methods to compare identified metabolite signals between samples from patients with recurrence of breast cancer and those from patients having no evidence of disease.

The present invention is a comprehensive two-dimensional gas chromatograph system and method including a modulator wherein the pulsing of the modulator is synchronized with data acquisition so that the results are reproducible.

A method to simulate distillation of a petroleum stream by comprehensive two-dimensional gas chromatography including the step of separating said petroleum stream with a two-dimensional gas chromatograph to determine polarity as a function of temperature, and integrating vertically the two-dimensional gas chromatograph at a given temperature to determine signal intensity as a function of temperature.

A method for detecting substances or mixtures of substances within a sample in an apparatus for comprehensive two-dimensional gas-chromatographic analysis according to the present invention, comprising the steps of:

• • subjecting the sample to a first separation within a first capillary column;
  • modulating in time the effluents from the first column by means of the subdivision into adjacent fractions of the effluents from the first column and subsequently sending each fraction into a second capillary column, the modulation of the effluents being periodic with a first modulation frequency f₁ of the sample;
  • separating each of the fractions in the aforesaid second capillary column; and
  • detecting, at the end of the second capillary column, the effluents by means of periodic sampling by discrete time points at a second frequency f₂.

The method moreover envisages the step of generating the first frequency f₁ of modulation and the second frequency f₂ of sampling in such a way that sampling by discrete points downstream of the second column will be in phase with the modulation of the effluents from the first column.