Mixture gas chromatography mass spectrometry. Medical search. Frequent questions

Quantitative hydrocarbon group- analysis of gasoline and diesel fuel by supercritical fluid chromatography. (cdc.gov)
The high separation power and short analysis time obtained demonstrate for the first time that supercritical fluid chromatography is a fast and reliable technique for the analysis of lignin-derived phenols in complex environmental samples. (lu.se)
Alkaline cupric oxide (CuO) oxidation is one of the mostly performance supercritical fluid chromatography (UHPSFC) adopted methods for analyzing lignin in various complex using columns with sub-2 m packing can further improve environmental matrices such as soils and sediments [9]. (lu.se)
UHPSFC , ultra- pacted by other parameters, such as the addition of the mod- high performance supercritical fluid chromatography ifier and the change of the mobile phase density [20]. (lu.se)

A new software program was recently reported that integrates all of the available mass spectrometric information from GC-HRTOFMS analysis into a concise report. (jeolusa.com)
c) GC-MS : Gas chromatography with mass spectrometric detection was carried out using similar GC conditions to those described above. (gla.ac.uk)

In 1964, Electronic Associates, Inc. (EAI), a leading U.S. supplier of analog computers, began development of a computer controlled quadrupole mass spectrometer under the direction of Robert E. Finnigan. (wikipedia.org)
The most common type of mass spectrometer (MS) associated with a gas chromatograph (GC) is the quadrupole mass spectrometer, sometimes referred to by the Hewlett-Packard (now Agilent) trade name "Mass Selective Detector" (MSD). (iitk.ac.in)
Pyrolysis gas chromatograph quadrupole mass spectrometer (Py-GC-QMS) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometer (MALDI-TOFMS) are powerful tools for analyzing polymeric materials. (jeolusa.com)

The first on-line coupling of gas chromatography to a mass spectrometer was reported in the late 1950s. (wikipedia.org)
The GC-MS is composed of two major building blocks: the gas chromatograph and the mass spectrometer. (wikipedia.org)
The molecules are retained by the column and then elute (come off) from the column at different times (called the retention time), and this allows the mass spectrometer downstream to capture, ionize, accelerate, deflect, and detect the ionized molecules separately. (wikipedia.org)
The mass spectrometer does this by breaking each molecule into ionized fragments and detecting these fragments using their mass-to-charge ratio. (wikipedia.org)
Sometimes two different molecules can also have a similar pattern of ionized fragments in a mass spectrometer (mass spectrum). (wikipedia.org)
Combining the two processes reduces the possibility of error, as it is extremely unlikely that two different molecules will behave in the same way in both a gas chromatograph and a mass spectrometer. (wikipedia.org)
The molecules take different amounts of time (called the retention time) to come out of (elute from) the gas chromatograph, and this allows the mass spectrometer downstream to capture, ionize, accelerate, deflect, and detect the ionized molecules separately. (iitk.ac.in)
Another relatively common detector is the ion trap mass spectrometer. (iitk.ac.in)
The ice is sublimated continuously with a near-infrared laser, releasing the gases, which are then analyzed on a laser absorption spectrometer. (copernicus.org)
It involves the use of a vapour phase dehydrogenation micro‐reactor (Cu, 300°C) located between the chromatographic column and the mass spectrometer or between the injection port and the column. (rudn.ru)

The gas chromatograph utilizes a capillary column whose properties regarding molecule separation depend on the column's dimensions (length, diameter, film thickness) as well as the phase properties (e.g. 5% phenyl polysiloxane). (wikipedia.org)
Cui LY, Ye WM, Wang Q, Chen YG, Chen B, Cui YJ (2019) Investigation on gas migration in saturated bentonite using the residual capillary pressure technique with consideration of temperature. (springer.com)
1) in the first part of the study, the analytical methods examined were isocratic high pressure liquid chromatography (HPLC) with ultraviolet (UV) detection, capillary gas chromatography (GC) with temperature programming and flame ionisation detection and gas chromatography-mass spectrometry (GC-MS). Twelve NSAIDs in common use in the UK were selected as test compounds for the evaluation of the separating ability, selectivity and sensitivity of detection of the three methods. (gla.ac.uk)

Like liquid chromatography-mass spectrometry, it allows analysis and detection even of tiny amounts of a substance. (wikipedia.org)
This new analytical method has been developed by the IFRA Analytical Working Group to identify and to quantify the 57 fragrance substances and their relevant isomers at a concentration higher than 0.002% (20 mg/kg) in ready to inject fragrance materials and oils using Gas Chromatography with FID (GC-FID) or with Mass Spectrometry (GC-MS) detection. (sigmaaldrich.com)
It is instrumental in isolating, identifying, and quantifying individual components in mixtures, making it effective for adulterant or contaminant detection in spices. (fmtmagazine.in)
In addition, fluorescence spectrometry and electrochemical detection (ECD) were examined to assess their value as additional HPLC detection systems which might increase the selectivity or sensitivity of the method. (gla.ac.uk)

These inclusions preserve for us tiny samples of the liquid and/or the gas phase that was present during formation, although in some cases they may have undergone significant changes from the original material. (usgs.gov)
Burners mix air (or oxygen) and gas (natural gas or liquid petroleum gases) for efficient combustion and are used to heat glass in furnaces of all sizes. (fusetech.com)
A convenience sample of 26 bulk liquid flavorings obtained from two coffee roasting and packaging facilities in the USA was analyzed for 20 volatile organic chemicals present in the headspaces of vials containing flavoring liquids using gas chromatography-mass spectrometry. (cdc.gov)
Gas chromatography mass spectrometry, liquid chromatography-tandem mass spectrometry, and pyrosequencing were used to measure plasma OCPs, serum sex hormones, and whole blood methylation levels of sex hormone receptors, respectively. (bvsalud.org)
Gas-liquid and thin layer chromatographic systems for the analysis are discussed. (erowid.org)
The primary amine (MDP-2-B) and the N-substituted derivatives of MDP-2-B are separated by reversed-phase liquid chromatography under acidic mobile-phase conditions. (erowid.org)
Over the years, technologic advances in electronics and detectors have allowed GC/MS to detect ever smaller concentrations of compounds, as has the addition of other analytical techniques, such as liquid chromatography. (medscape.com)

Intermediary metabolites extracted using ethyl acetate and Tertbutyldimethylsilyl derivatives generated and quantified by gas chromatography-mass spectrometry using protocols established in our laboratory. (bepress.com)

In contrast to steady-state protein abundance, which may be quantified directly in mass spectrometry (MS) by spectral intensity 16 , 17 or sampling frequency 18 , 19 , protein turnover rates cannot be predicted from steady-state data 20 , requiring instead methods that can distinguish old and new protein molecules in mass spectra 11 , 21 . (nature.com)
Three regioisomeric 3,4-methylenedioxyphenethylamines having the same molecular weight and major mass spectral fragments of equivalent mass have been reported as components of clandestine drug samples in recent years. (erowid.org)

The potential of pyrolysis gas chromatography-mass spectrometry (Py-GCMS ) as a tool for the estimation of post-mortem age of bones has been investigated. (uc.pt)
To date the samples, scientists used a combination of both gas chromatography-mass spectrometry and sequential thermal desportion-pyrolysis. (msu.edu)

Electronic nose, Ion chromatography, and Isotope Ratio Mass Spectrometry (IRMS) were also other chromatographic techniques. (fmtmagazine.in)
Gas-Isotope-ratio mass spectrometry (G-IRMS) allows the precise measurement of mixtures of naturally occurring light stables isotopes. (lu.se)

Therefore, when an identifying mass spectrum appears at a characteristic retention time in a GC-MS analysis, it typically increases certainty that the analyte of interest is in the sample. (wikipedia.org)
Using an integrated platform of metabolic labeling, high-resolution mass spectrometry and computational analysis, we report here a comprehensive dataset of the in vivo half-life of 3,228 and the expression of 8,064 cardiac proteins, quantified under healthy and hypertrophic conditions across six mouse genetic strains commonly employed in biomedical research. (nature.com)
The researchers subjected the materials in the containers to Fourier-transform infrared spectroscopy and gas chromatography /mass spectrometry analysis. (phys.org)
In this guidebook, we will introduce polymeric material analysis solutions that make full use of JEOL's high-performance mass spectrometers. (jeolusa.com)
Analysis of complex mixtures with gas chromatography coupled with high-resolution time-of-flight mass spectrometry (GC-HRTOFMS) can produce a large amount of data. (jeolusa.com)
GC/MS analysis allows separation of compounds based on their retention time within a chromatography column and identification of each compound by the characteristic fragments into which a given chemical is broken following ionization of the compound. (medscape.com)
The new ultra-high performance super- critical fluid chromatography method was also applied for the qualitative and quantitative analysis of lignin-derived phenolic compounds obtained upon alkaline cupric oxide oxida- tion of a commercial humic acid. (lu.se)

In this paper, we report presence of various organic products formed in a flowing atmospheric glow discharge fed by gas mixture containing 1-5 % of methane in nitrogen, which mimics the Titan's atmosphere. (open.ac.uk)
The article describes various factors pertinent to ionization methods, namely glow discharge mass spectrometry and secondary ion mass spectrometry. (asminternational.org)

If signals of interest of different isomers could not be completely separated in NMR, the ratio was determined by Gas Chromatography (GC) measurement under ISO/IEC 17025 accreditation. (sigmaaldrich.com)

In the present study we tested in vitro the mixture of volatile organic compounds (VOCs) produced by M. yucatanensis for the allelochemical effects against phytopathogenic fungi and fungoids, other endophytic fungi, and plants. (usda.gov)
Almost all compounds identified in the VOCs mixture were not previously reported from other Muscodor species. (usda.gov)
These compounds can be detected using expensive, bulky machines, such as gas chromatographs and mass spectrometers. (technologyreview.com)
It is used to separate and analyse the complex mixtures of compounds. (fmtmagazine.in)
An examination of the mass spectra of alcohols and carbonyl compounds permits the determination of molecular mass, the location of hydroxyl group and the determination of branching at the β‐carbon atom. (rudn.ru)
All of the test compounds were eluted from the column and could be detected by UV spectrometry at a sample size of 5 nanograms on-column. (gla.ac.uk)
Five of the test compounds could be detected by fluorescence spectrometry and seven by ECD. (gla.ac.uk)
Three compounds, all pyrazolidine diones, could be chromatographed without derivatisation but produced a mixture of products following reaction with the methylating agent, diazomethane. (gla.ac.uk)
of a mixture are defined as those present in concentrations of ≥1% by weight (0.1% by weight for compounds that are carcinogenic or toxic to the reproductive system). (cdc.gov)
The compounds are not completely resolved by gas chromatography on an HP-1 phase, and the separation is complicated by extensive thermal degradation of the N-hydroxy derivative (MDP-2-OHB). (erowid.org)
The mass spectra for these compounds provide specific structural information for the identification of these compounds. (erowid.org)

Alternatively, if one of the reactants or products is a gas, pressure measurements are used to determine reaction rates by monitoring pressure changes. (jove.com)
For example, during hydrogen peroxide decomposition, the reaction rate is studied using a manometer to monitor the pressure of oxygen gas released. (jove.com)
As the reaction progresses and more oxygen gas evolves, the pressure rises. (jove.com)
For prolonged reactions, samples, or aliquots, can be taken from the reaction mixture at regular time intervals. (jove.com)
The relative concentrations are then measured using instrumental techniques like gas chromatography, mass spectrometry, or titration, to compute reaction rates. (jove.com)

Environmental and breathing zone samples were analyzed for organic solvent s in the paint department of Ackerley Communications, Incorporated (SIC-7312), Stoneham, Massachusetts in March, 1983. (cdc.gov)
One of the samples was analyzed by gas chromatography/mass spectrometry to identify its components. (cdc.gov)
In 6 well compensated, stable alcoholic cirrhotic patients and 8 controls, serial plasma samples were obtained before and 1h, 3h, 6h after a single oral BCAA mixture enriched with leucine (BCAA/ Leu). (bepress.com)
Flavoring samples included hazelnut, French vanilla, amaretto, chocolate, and caramel as well as some flavoring mixtures containing added fruit flavors such as cherry and raspberry. (cdc.gov)

The difference in the chemical properties between different molecules in a mixture and their relative affinity for the stationary phase of the column will promote separation of the molecules as the sample travels the length of the column. (wikipedia.org)
The difference in the chemical properties between different molecules in a mixture will separate the molecules as the sample travels the length of the column. (iitk.ac.in)

In air pollution studies: They measure atmospheric concentrations of gases like carbon dioxide or ozone using advanced analytical techniques. (freescience.info)

The solvent mixture resembled mineral spirits. (cdc.gov)

The mass spectrometry process normally requires a very pure sample while gas chromatography using a traditional detector (e.g. (wikipedia.org)

Using the ideal gas equation, pressure values recorded at different time points are converted to concentrations. (jove.com)
Surprisingly, plasma concentrations of all TCA cycle intermediates in cirrhotic patients were consistently higher at baseline and remained elevated at 1h, 3h, and 6h after a single oral BCAA mixture enriched with leucine (BCAA/Leu) compared to controls (Table). (bepress.com)

Helium has traditionally been the first-choice carrier gas, owing to its inertness, performance, and relatively cheap price. (chromatographyonline.com)
In 2012-2013, the global helium shortage increased the number of GC users switching to alternative carrier gases and improved the availability of information on their use. (chromatographyonline.com)
DART mass spectrometry commonly uses helium as the DART gas. (jeolusa.com)
With the looming helium shortage, other gases are being evaluated for DART. (jeolusa.com)

Under a suitable thermal oxidation regime, vegetable oils yield a mixture of volatile and semivolatile organics that exhibit very high antimicrobial activities against a variety of microbial species. (spectroscopyonline.com)

We used a sample crusher and a gas chromatography-mass spectrometry (GC-MS) system to analyze for organic and inorganic volatiles present as major to trace constituents in inclusions. (usgs.gov)

The ultraviolet and mass spectra of isomers are similar, but proton magnetic resonance and infrared spectra are distinctly different, and reference spectra and data are provided. (erowid.org)

QGC and BKMR showed a positive combined effect in the associations of OCPs mixtures on T2DM among premenopausal females, and positive effects but not statistically significant among males and postmenopausal females. (bvsalud.org)

Gas chromatography-mass spectrometry (GC-MS) allows isolation and identification of individual analytes within a complex mixture. (chromatographyonline.com)
The composition varies from a single major compound ( e.g. , water) in a single phase to a very complex mixture in one or more phases. (usgs.gov)

The present work systematically quantifies the impact on soot moments, soot related statistical correlations and Particle Size Distributions (PSDs) using a fully coupled transported joint probability density function (JPDF) method featuring a 78-dimensional joint-scalar space, including enthalpy, gas phase species with the PSD discretised using 62 size classes via a mass and number density preserving sectional method. (imperial.ac.uk)
Similar observations are made for correlations between the soot volume fraction and the mass fractions of gas-phase species such as CO, OH, H and C2H2. (imperial.ac.uk)

Mass fragmentographic determination of polymethylbiphenyl in foods contaminated with petroleum products. (cdc.gov)
A method for structure determination of aliphatic alcohols within mixtures is described. (rudn.ru)

Also known as the "spring" or "source".Inside the furnace, the hot spot is that area on the surface of the melt which has reached the maximum temperature (at which batch reactions have been completed and dissolved gases have been reduced to acceptable levels). (fusetech.com)

Gas chromatography-mass spectrometry (GC-MS) is an analytical method that combines the features of gas-chromatography and mass spectrometry to identify different substances within a test sample. (wikipedia.org)

Seven PFAS were quantified using isotope-dilution tandem mass spectrometry. (cdc.gov)

Identifying C. innocuum has become faster and more accurate after the introduction of molecular techniques such as 16S RNA sequencing and matrix-associated laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry ( 6 ). (cdc.gov)

We are proud to introduce two ready-to-use certified reference material mixtures suitable for use as calibrants for the above mentioned new IFRA method. (sigmaaldrich.com)

In the qNMR measurements, a value for the mass fractions (g/g) was obtained, and direct traceability to the SI unit was achieved through the use of acknowledged NIST primary reference materials. (sigmaaldrich.com)

A mass and number density preserving sectional model is here combined with a transported joint-scalar probability density function (JDPF) method that enables a fully coupled scalar space of soot, gas-phase species and enthalpy. (imperial.ac.uk)
We present a new method to extract the gases from ice cores and measure their greenhouse gas composition. (copernicus.org)

Gas breakthrough pressure is a significant parameter for the gas exploration and safety evaluation of engineering barrier systems in the carbon dioxide storage, remediation of contaminated sites, and deep geological repository for disposal of high-level nuclear waste, etc. (springer.com)

In the end, the pattern-recognition software will be able to recognize specific chemicals, while the neural networks will identify the pattern of a mixture of chemicals. (technologyreview.com)
They can detect patterns of chemicals, but cannot identify individual chemicals in the mixture - that typically requires gas chromatography and mass spectrometry (GC-MS). But the SUNY sensor system "seems to be able to detect patterns of chemicals and to identify the chemicals themselves," he says. (technologyreview.com)
The standard dictates that the chemical manufacturer, distributor, or importer systematically categorize hazards present in chemical mixtures, identify hazardous properties and routes of exposure for each chemical constituent, and share these hazards in a safety data sheet (SDS). (cdc.gov)

In this work, we compare sensitivity levels when using the combination EI/FI and EI/PI ion sources when He and N2 are used as the GC carrier gas. (jeolusa.com)

Individual and mixtures of OCPs exposure were positively linked to elevated risk of T2DM. (bvsalud.org)

In this study, state-of-the-art instrumentation two-dimensional gas chromatography (GC × GC) coupled photoionization─time of flight mass spectrometry was employed to investigate the composition of dodecene products produced from olefin oligomerization. (jeolusa.com)

Mass number Number of protons and neutrons Atomic number Number of protons Atomic Structure Cl 17 35 Proton Neutron Electron Relative mass 1 1 negligible Charge + 0 - location nucleus nucleus shells Atoms of the same element can have different numbers of neutrons - these atoms are called isotopes of that element. (studyslide.com)
Same atomic number Different mass number The relative atomic mass of an element (Ar) compares the mass of atoms of the element, has the same value as the mass number. (studyslide.com)
The relative formula mass (Mr) of a compound is the sum of the relative atomic masses of the atoms in the numbers shown in the formula. (studyslide.com)

Additionally, when MALDI is used with a high-resolution TOFMS, the accurate mass of each ion in the polymer series can be used to calculate their elemental compositions. (jeolusa.com)

The JMS-S3000 SpiralTOF™-plus Ultra-High Mass Resolution MALDI-TOFMS System time-of-flight optics design utilizes a figure-eight ion trajectory to allow a 17m flight path to fit in an extremely small console. (jeolusa.com)
Test for determining gas breakthrough pressure is very difficult and time-consuming, due to the low/ultra-low conductivity of the specimen. (springer.com)
But from time to time it can also be frustrating because of lack of critical mass in non-core but technically interesting areas. (lu.se)

The mass differences between isotopes leads to quantifiable kinetic- or mass dependent fractionation that is characteristic of the biological, chemical or physical history of a sample. (lu.se)

It is also difficult to get a comprehensive and high-precision model based on limited results obtained through individual experiments, as the measurements of gas breakthrough pressure were influenced by many factors. (springer.com)

The solution containing the chloropropyl esters was concentrated and then analyzed using gas chromatography-positive chemical ionization-tandem mass spectrometry. (cdc.gov)

Using gas chromatography‑mass spectrometry (GC‑MS), 76 and 99 components were identified in the myrrh and frankincense essential oils, respectively, with the most abundant components, 2‑Cyclohexen‑1‑one, 4‑ethynyl‑4‑hydroxy‑3,5,5‑trimethyl‑ and n‑Octylacetate, accounting for 12.01 and 34.66%, respectively. (spandidos-publications.com)

Abstract The electrode ionomer plays a crucial role in the catalyst layer (CL) of a proton-exchange membrane fuel cell (PEMFC) and is closely associated with the proton conduction and gas transport properties, structural stability, and water management capability. (journaltocs.ac.uk)
The antibacterial properties of the mixture helped to additionally preserve the soft tissues in the remains. (msu.edu)

However, flavoring formulations that contain diacetyl and 2,3-pentanedione might not list these ingredients because they are generally recognized as safe to ingest, may be part of a proprietary mixture deemed a trade secret, or may not be required to be listed if they are present at <1% composition. (cdc.gov)

Anatomy7

Organisms7

Chemicals and Drugs69

Analytical, Diagnostic and Therapeutic Techniques and Equipment42

Phenomena and Processes28

Disciplines and Occupations5

Anthropology, Education, Sociology and Social Phenomena2

Technology, Industry, Agriculture1

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Supercritical fluid chromato4

Spectrometric2

Quadrupole mass spectrometer3

Spectrometer10

Capillary3

Detection4

Liquid7

Metabolites1

Spectral2

Pyrolysis2

IRMS2

Analysis7

Glow discharge2

Measurement1

Compounds11

Reaction5

Samples4

Molecules2

Atmospheric1

Solvent1

Detector1

Concentrations2

Helium4

Thermal1

Analyze1

Ultraviolet1

Females1

Complex2

Correlations2

Determination2

Reactions1

Substances1

Isotope1

Techniques1

Suitable1

Fractions1

Method2

Nuclear1

Identify3

Carrier1

Exposure1

Instrumentation1

Atoms3

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Characteristic1

Individual1

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Components1

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Composition1