Amount isotope dilution mass spectrometry. Medical search. Frequent questions

Since most of the current procedures require complex and costly instrumental configurations, we have developed a simple and rapid gas chromatography tandem mass spectrometry (GC/MS/MS) method able to detect SeCN- in water samples with a LOD of 0.1 ng/g Se. (bvsalud.org)
Tandem mass spectrometry is a method to further enhance the specificity of mass spectrometry. (myadlm.org)
Magera MJ, Helgeson JK, Matern D, Rinaldo P. Methylmalonic acid measured in plasma and urine by stable-isotope dilution and electrospray tandem mass spectrometry . (kcl.ac.uk)
In the mouse bioassay, when the injected matography-tandem mass spectrometry method for quan- dose is high, mice typically develop signs of botulism with- tifying active toxin, where the amount of toxin can be in 8 hours. (cdc.gov)
It also requires several days to determine the toxin ionization-tandem mass spectrometry (HPLC- level and type (4-6). (cdc.gov)

An automated analytical method was developed using solid phase microextraction (SPME) gas chromatography (GC) and high-resolution mass spectrometry (HRMS) with selected ion mass detection and isotope-dilution techniques. (cdc.gov)
Determination of 3-quinuclidinyl benzilate (QNB) and its major metabolites in urine by isotope dilution gas chromatography/mass spectrometry. (cdc.gov)
We also present a novel method for characterization of the materials using liquid chromatography mass spectrometry to quantify the analytes of interest. (cdc.gov)
We describe a novel method to measure petroleum distillates in BAL fluid using gas chromatography-mass spectrometry (GC/MS). METHODS: n-Hexane, n-heptane, n-octane, methylcyclopentane, and cyclohexane were measured in BAL fluid specimens by headspace solid-phase microextraction/gas chromatography/mass spectrometry. (cdc.gov)
A novel analytical method for the simultaneous gas chromatography-mass spectrometry (GC-MS) determination of methionine and selenomethionine in food samples is described. (bvsalud.org)
In the present study, we developed a method for the determination of thiocyanate in dilute samples using isotope dilution headspace gas chromatography-coupled high-resolution, accurate-mass mass spectrometry (GC-HRMS). (bvsalud.org)
These proteins' concentrations were determined in each sample using stable isotope dilution (SID) and selected reaction monitoring (SRM) LC-MS/MS [Liquid chromatography-mass spectrometry] analysis [refs 23, 24] (Supplementary Tables 2 and 3). (harvard.edu)
Furthermore, with the most commonly used chemometrics algorithms, it is difficult to accurately extract and discriminate the huge amounts of data generated by mass spectrometry, such as ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF). (hindawi.com)
The main disadvantage of flight mass spectrometry (MALDI-TOF-MS) or by high- the mouse bioassay is that it requires euthanizing many ani- performance liquid chromatography (HPLC)-electrospray mals. (cdc.gov)
Cholesterol and oxidized cholesterol metabolite serum levels of FH and of healthy, gender/age matched control subjects were measured by combined gas chromatography - mass spectroscopy. (biomedcentral.com)
Steam distillation/drop-by-drop extraction with gas chromatography-mass spectrometry for fast determination of volatile components in jujube (Ziziphus jujuba Mill. (biomedcentral.com)
A method coupling steam distillation/drop-by-drop extraction with gas chromatography-mass spectrometry (S3DE/GC-MS) was developed to determine the volatile components of jujube extract. (biomedcentral.com)
Gas chromatography-mass spectrometry (GC-MS) is typically employed to analyze volatile components in flavorings. (biomedcentral.com)

All four laboratories used isotope dilution mass spectrometric techniques, but two laboratories (BAM and NIST) used thermal ionization mass spectrometry (TIMS) and two laboratories (IRMM and LGC) used inductively coupled plasma mass spectrometry (ICP-MS). Both techniques require spiking and combustion of the sample prior to the instrumental determination to quantify the amount of sulfur in the fuels. (nist.gov)
This MDHS describes a method for measuring exposure to a range of metal and metalloid elements in workplace air using inductively coupled plasma-atomicemission spectrometry (ICP-AES). (speciation.net)
Historically, in this program the mercury emitted by a NIST prime Hg generator was value-assigned on the SI using an SRM 3133® Hg standard combined with isotope dilution cold vapor inductively coupled mass spectrometry measurements. (ilmexhibitions.com)
nConcentrations of U and Th isotopes in Okinawa Trough and East China Sea sediment cores were determined by isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS) to investigate the behavior of redox sensitive uranium in suboxic hemipelagic sediments and its significance in oceanic uranium balance. (go.jp)
To achieve this aim each of the separate As-containing species will need to be determined using methods based on elemental speciation, whereby a chromatographic separation is coupled to a suitable atomic spectroscopic detector, for example HPLC-ICP-MS (inductively coupled plasma mass spectrometry in combination with HPLC). (clinlabint.com)
Samples were then analyzed using isotope dilution-inductively coupled plasma mass spectrometry (ID-ICP/MS). Results specific to the Toronto area were compared to the mercury levels published by the U.S. FDA in 2006 and by Health Canada in 2007. (oers.ca)

The product peptides derived from the endopeptidase injection containing a sample with more than a minimum activities of BoNTs are detected by matrix-assisted laser- lethal dose show symptoms of botulinum intoxication and desorption ionization time-of-flight mass spectrometry. (cdc.gov)

This method employs isotope dilution to quantify precisely trace amounts of aldehydes with limits of detection in the low parts per trillion range. (cdc.gov)
The usual approach to dermal exposure assessment is to process samples by chemical methods that use reactants to digest the metal particles and quantify the mass. (cdc.gov)
Use of reactant-assisted analytical chemistry to quantify amounts of metal sensitizers on samples could overestimate biologically relevant exposure. (cdc.gov)

This method consists of two approaches: isotope dilution mass spectrometry (IDMS) for the determination of total metals and speciated isotope dilution mass spectrometry (SIDMS) for the determination o. (speciation.net)

In addition to the use of stable isotopes, radioactive isotopes can be employed in isotope dilution which is often encountered in biomedical applications, for example, in estimating the volume of blood. (wikipedia.org)
Both radioactive and stable isotopes were thus used to measure the potassium and sodium of the body. (humankinetics.com)
Currently, deuterium ( 2 H) and oxygen-18 ( 18 O), which correspond to nonradioactive stable isotopes, are the most commonly used isotopes for the measurement of TBW. (humankinetics.com)
Thus, deuterium is the most frequently used isotope to estimate TBW because it is a stable isotope and easy to obtain and has lower costs than tritium or oxygen-18 with no radioactivity exposure. (humankinetics.com)
Annual Meeting Stable Isotope Mass Spectrometry Users Group (SIMSUG) 2002, Belfast, N Ireland, 17-18 January 2002. (rothamsted.ac.uk)
The aim of this study was to monitor seasonal changes in stable isotopes of pool freshwater and harp seal ( Phoca groenlandica ) body water, and to study whether these potential seasonal changes might bias results obtained using the doubly labelled water (DLW) method when measuring energy expenditure in animals with access to freshwater. (biologists.com)

For both modes, absolute quantification is achieved by spiking in the reference in known amounts. (genengnews.com)
MS/MS) and isotope dilution quantification method. (who.int)
Isotope dilution is used for target analyte quantification. (jeolusa.com)

Isotope dilution is classified as a method of internal standardisation, because the standard (isotopically enriched form of analyte) is added directly to the sample. (wikipedia.org)
In addition to high-precision analysis, isotope dilution is applied when low recovery of the analyte is encountered. (wikipedia.org)
Consider a natural analyte rich in isotope iA (denoted as A), and the same analyte, enriched in isotope jA (denoted as B). Then, the obtained mixture is analyzed for the isotopic composition of the analyte, RAB = n(iA)AB/n(jA)AB. (wikipedia.org)
Isotopic mass labeling leads to a distinct mass difference of structurally identical reference and target analyte. (genengnews.com)
Isobaric mass labeling leads to isobaric analytes that can be differentiated by isotopic mass reporters released from the analyte during tandem mass spec. (genengnews.com)
In order for an analyte to be measured using mass spectrometry it must carry a charge and be in the gas phase. (myadlm.org)
An analyte with a molecular weight of 415 and a charge of +1 will have a mass-to-charge ratio of 415. (myadlm.org)
With the mass of our analyte known, we need to decide what type of mass spectrometer to use for analysis. (myadlm.org)
For an analyte at a known mass-to-charge ratio, the amount of positive or negative charge and the frequency at which the diagonal pairs switch their sign is optimized to produce a successful ion flight path through the quadrupole. (myadlm.org)

An early application of isotope dilution in the form of radiotracer method was determination of the solubility of lead sulphide and lead chromate in 1913 by George de Hevesy and Friedrich Adolf Paneth. (wikipedia.org)
Method 2.6 Determination of Macro-amounts of Sulfur in Polymers. (chemtec.org)

When using isotope dilution, particularly deuterated water, two body fluid samples from urine, blood, or saliva are collected: one just before administration of the deuterium dose to determine the natural background levels and the second after allowing enough time for penetration of the isotope. (humankinetics.com)

The main advantage of using tritium ( 3 H), the radioactive isotope of hydrogen, is that it is readily available and easily assayed by scintillation counting. (humankinetics.com)
This workshop is open to experts and stakeholders from both radionuclide metrology and inorganic chemical analysis communities with experience or interest in using mass spectrometry to support metrological analysis of radioactive elements in applications such as nuclear power, environmental stewardship, forensics and medicine, and the nuclear data supporting the counting methods used in radionuclide metrology. (bipm.org)
proper usage of mass spectrometry instrumentation in analysing radioactive materials - are available in advance of the workshop to help set the stage (see at the bottom of the page). (bipm.org)

In addition, unlike traditional analytical methods which rely on signal intensity, isotope dilution employs signal ratios. (wikipedia.org)

It is also used in chemistry labs for iodine titration because it reacts in equimolar amounts with elemental iodine. (alostmind.com)

Our results highlight that there is a taxonomic component to silicon isotope fractionation during biosilicification, possibly via a shared or related biochemical transport pathway. (copernicus.org)
Variations in background levels of deuterium and oxygen-18 in freshwater sources may be due to seasonal changes in physical processes such as precipitation and evaporation that cause fractionation of isotopes. (biologists.com)

How long it takes a given ion to travel down the flight tube is how ions of different mass-to-charge ratios are distinguished. (myadlm.org)
The range of isotope ratios in these samples is 0.781-16.9 for 187 Re/ 188 Os and 0.2274-0.927 for 187 Os/ 188 Os. (nature.com)
a ) Re and Os concentrations and isotope ratios. (nature.com)

Owing to both of these advantages, the method of isotope dilution is regarded among chemistry measurement methods of the highest metrological standing. (wikipedia.org)

Based on recent developments in quantitative mass spectrometry, biological reference materials have been generated that can be used as internal (quality) controls for proteomics utilizing the characteristics of isotope-dilution mass spectrometry (ID-MS). (genengnews.com)

In general, two different methods of chemical labeling are used-isotopic mass labeling and isobaric mass labeling. (genengnews.com)
Topics for discussion will include ionization methods, the different types of mass spectrometers used clinically, different methods of analysis, and highlight some future areas where mass spectrometry will most likely be applied. (myadlm.org)
In the last 10 years, two methods have been described to accurately analyse human milk vitamin B12 by modifying existing CPBAs to remove interfering amounts of haptocorrin from the milk sample. (kcl.ac.uk)
The explosive peroxide compounds triacetone triperoxide (TATP) and hexamethylenetriperoxide diamine (HMTD) are difficult to detect by conventional mass spectrometry methods. (jeolusa.com)
Current methods for detecting BoNT include a mouse cause human botulism (A, B, E, and F). We developed a bioassay (2-4) and an enzyme-linked immunosorbent assay rapid, mass spectrometry-based method (Endopep-MS) to (ELISA) (5,6). (cdc.gov)
In order to determine the amount of a substance such as Vitamin C by titration, we can use iodometry methods. (alostmind.com)

Mixing of the isotopic standard with the sample effectively "dilutes" the isotopic enrichment of the standard and this forms the basis for the isotope dilution method. (wikipedia.org)
The Tandem Mass Tag® (TMT®) core structure invented by Proteome Sciences allows for the generation of different sets of isotopic and isobaric mass tags. (genengnews.com)
Although these materials are not pure compounds, a library of DART mass spectra can be created and searched to identify materials, and exact mass measurements coupled with accurate isotopic abundances can be used to identify unknown components. (jeolusa.com)

P.2 left column 2nd paragraph:'Second, [investigators] accurately quantified a subset of identified proteins to establish a 'calibration' for the MS [mass spectrometry] intensities determined for all identified proteins. (harvard.edu)

The expanded panel of lipid biomarkers included 53 multihack apex and lipid metabolites measured using a Triple Quadrupole mass spectrometer Agilent, New Castle, DE, USA, set to a targeted multiple reaction monitoring mode. (bazancorp.com)

In general, an assay that uses a mass spectrometer as the final detection method will involve a sample preparation step, a chromatographic separation and measurement with a mass spectrometer. (myadlm.org)
identify challenges to the use of mass spectrometry in the radionuclide metrology laboratory, including relating mass measurement to activity measurement. (bipm.org)
Further, AccuTOF-DART permits exact mass measurements without requiring the presence of a reference standard during the sample measurement. (jeolusa.com)
As a successor to Prof. Folke Ingman in the position of IUPAC representative to the Consultative Committee for Amount of Substance (CCQM), International Bureau of Weights and Measures (BIPM), Paris, France, I attended a working group meeting and a workshop on measurement uncertainty held 29 November- 3 December 1999 at BIPM. (iupac.org)

Isotope dilution analysis is a method of determining the quantity of chemical substances. (wikipedia.org)
In its most simple conception, the method of isotope dilution comprises the addition of known amounts of isotopically enriched substance to the analyzed sample. (wikipedia.org)
Analytical application of the radiotracer method is a forerunner of isotope dilution. (wikipedia.org)
Isotope dilution is analogous to the mark and recapture method, commonly used in ecology to estimate population size. (wikipedia.org)
A novel isotope dilution method for the analysis of inorganic chloride in fuel oil matrix is presented. (bvsalud.org)
The method reliably quantified as little as 4 pmol thiocyanate in EBC and could detect even lower amounts. (bvsalud.org)
1. Introduction This method can determine the amount of specific metal and metalloid particulates in the workplace atmosphere. (speciation.net)
Because it is mostly found in the fat-free body in a relatively constant amount, assessment of body water has been of interest as a method of body composition assessment for almost 100 years. (humankinetics.com)
It is therefore strongly recommended that analysis of seasonal changes in background levels of isotopes is performed before the DLW method is applied on (free-ranging) animals, and to use a control group in order to correct for changes in background levels. (biologists.com)
The choice of detection method is important for trace amounts of carboxylic acids in biological samples. (encyclopedia.pub)

If the amount of isotope is known and the baseline and equilibration concentrations are measured, the volume in which the isotope has been diluted can be calculated. (humankinetics.com)
This clay layer has high platinum group element (PGE) concentrations and features a conspicuous negative Os isotope anomaly ( 187 Os/ 188 Os as low as ~0.2), indicating an influx of extraterrestrial material. (nature.com)
Below, we report bulk major- and trace-element compositions, Re-Os isotope data and PGE concentrations in the piston core samples, as well as detailed petrographic observations of this layer, that collectively indicate the presence of extraterrestrial material. (nature.com)
It is now clear that silicon isotopes are fractionated during biosilicification and that this phenomenon provides important information on past DSi concentrations in seawater. (copernicus.org)

Here, we present petrographic and geochemical evidence of a possible impact ejecta layer, dating from about 11 Ma, in deep-sea clayey sediment in the Northwest Pacific. (nature.com)

Oxygen-18 has the advantage that its dilution space more closely approximates TBW, but it can be adequately measured only by isotope ratio mass spectrometry, and the cost of 18 O-labeled water is about 15 times more than that of deuterium. (humankinetics.com)
Deuterium can be measured by infrared spectrometry but preferably by mass spectrometry. (humankinetics.com)
Extracellular fluid volume (20.0±4.3 vs 18.0±2.9) and total body water (42.3±9.6 vs 39.0±6.8) measured by bioimpedance and total body water by deuterium dilution (41.7±8.3 vs 39.4±6.2) were significantly greater in the treatment arm at week 4. (raftpubs.com)
67°C) was performed instead of enzymatic hydrolysis with cholylglycine hydrolase.14 Deuterium-labeled LCA, deoxycholic acid (DCA), chenodeoxycholic acid (CDCA), cholic acid (CA), and UDCA as internal standards were obtained from CDN Isotopes (Pointe-Claire, Canada). (dehydrogenase-signal.com)
The seals were offered daily amounts of capelin and kept under a seasonal photoperiod of 69°N. Large seasonal variations of deuterium and oxygen-18 in the pool water were measured, and the isotope abundance in the body water showed similar seasonal changes to the pool water. (biologists.com)

Analytes are then separated in a capillary column and quantified using multiple ion detection (MID) with mass spectrometry. (cdc.gov)
Conversely, chemical labeling, attaching small tags that carry isotope differences to the analytes, presents a simpler approach without the need to actually synthesize any peptides. (genengnews.com)
For analytes introduced into the mass spectrometer as a liquid, several types of sources exist including electrospray ionization and atmospheric pressure chemical ionization. (myadlm.org)
Although every type of mass spectrometer uses the same charged ions, how it separates individual analytes varies greatly. (myadlm.org)

It then goes on to suggest some important new developments in the field of inorganic mass spectrometry, which could have an important impact on future clinical assays. (clinlabint.com)

Following this investigation and using the same principle, tracer material was injected intravenously and allowed to reach a uniform distribution, and from the dilution achieved at equilibrium, the constituents of the body were measured. (humankinetics.com)

For example, all National Metrology Institutes rely significantly on isotope dilution when producing certified reference materials. (wikipedia.org)

Further analysis using speciated isotope dilution mass spectrometry revealed that the decay of Cr(VI) was accompanied by the formation of Cr(III) in the sweat model. (cdc.gov)
Once we have a way to get ions charged and into the gas phase, the most important aspect in the analysis is the mass-to-charge ratio, designated as m over z. (myadlm.org)
Due to the significant detection interference caused by the complex food matrix, false negative results caused by trace amounts of harmful substances, and the failure of targeted detection caused by endless adulteration, the specificity, and sensitivity of spectrum analysis need to be further improved. (hindawi.com)

[ 4 ] which allows sodium influx and a small amount of potassium efflux-neuronal depolarization results. (medscape.com)

Enter potassium dichromate mass in the upper (input) frame in the mass edit field above K2Cr2O7 formula. (alostmind.com)

The final stage of detection using a mass spectrometer is the focus of this portion of Pearls of Laboratory Medicine. (myadlm.org)
Mixtures of neutralizing anti- detection of the unique peptide products by mass spec- bodies are given to mice in conjunction with the sample. (cdc.gov)
Fluorescence detection following derivatization and mass spectrometry has the advantage of high sensitivity. (encyclopedia.pub)

Rapid Communications in Mass Spectrometry. (rothamsted.ac.uk)

Characterization of organometallic compounds by mass spectrometry can sometimes be complicated by problems with solubility and reactivity. (jeolusa.com)

Single quadrupole and triple quadrupole mass analyzers are the most common mass spectrometers found in the clinical laboratory, but it's important to recognize that laboratories are also using time of flight analyzers for specific applications. (myadlm.org)

If the fluid phase were erupted, the large mass of Br and Cl could have severely impacted the atmospheric chemistry upon eruption. (eurekalert.org)

Instead, we used Os isotope stratigraphy to constrain the depositional age of the core samples. (nature.com)

Since all ions are being accelerated by the same electric field, ions with a low mass-to-charge ratio will accelerate faster than ions with a high mass-to-charge ratio. (myadlm.org)
How long the mass spectrometer sits at a voltage and frequency combination is called the dwell time, during which only a limited number of ions are successfully reaching the detector. (myadlm.org)

We hypothesize that the amount and form of sensitizer on a sample that leaches in a biological fluid, as can be estimated using artificial sweat, may be a more relevant metric for assessing health risks. (cdc.gov)

In 1915, the dilution principle was first used in the study of human body composition when the use of a red dye to measure the plasma volume was extrapolated. (humankinetics.com)
However, only 28 distal impact ejecta or spherule layers have been confirmed from the Earth's surface 3 from the presence of shocked quartz, Ni-rich spinel, anomalous PGE enrichments or negative excursions of Os isotope composition. (nature.com)

None of the commonly used isotopes are distributed only in water. (humankinetics.com)

Currently standards must be generated one by one by incorporating isotope-labeled amino acids into the peptide sequence by chemical synthesis or by addition to culture media. (genengnews.com)
Mice receiving the appropriate anti-BoNT serotype anti- a unique cleavage site on a unique peptide, the mass-spe- body are asymptomatic and survive, while mice treated cific product peptides detected by mass spectrometry dif- with the other serotype antibodies show symptoms of botu- ferentiate active BoNT serotypes. (cdc.gov)

In addition to mass, the valence state also influences penetration through the outer stratum corneum of the skin and is an important consideration when assessing exposure to complex sensitizers such as Cr which have multiple valence states with differing penetration efficiencies. (cdc.gov)

Consistently, high amounts of primary bile acids as well as sterols were found in their feces. (biomedcentral.com)
In addition, plasma from FH patients contains elevated amounts of sterols and oxysterols. (biomedcentral.com)

GCMS spectra indicating the prevalence of significant amounts (>0.05 μmol/L) of uncommon bile acids were not observed. (dehydrogenase-signal.com)

After spiking known amounts of these references into each sample, absolute quantities were determined for the corresponding proteins by SRM. (harvard.edu)
For sample preparation this can be as simple as a dilution or as complex as solid phase extraction or immunoextraction. (myadlm.org)
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. (mayocliniclabs.com)

In particular, we look forward to the synergy of CCQM's expertise in mass spectrometry and CCRI's expertise in radionuclide materials analyses in guiding our discussions on the most suitable methodologies. (bipm.org)

As a consequence, in the hands of inexperienced groups data generation based on the improved resolving power of mass spectrometers continues to outperform the ability of many users for data interpretation. (genengnews.com)

We show that before eruption, Br and Cl were efficiently partitioned from the gas-saturated magma into a separate fluid phase, and we calculate the mass of halogens in the fluid phase. (eurekalert.org)

There are four basic assumptions that are inherent in any isotope dilution technique. (humankinetics.com)

The case can be confirmed if laboratory testing was not performed because either a predominant amount of clinical and nonspecific laboratory evidence of a particular chemical was present or a 100% certainty of the etiology of the agent is known. (cdc.gov)
This portion of the Pearls of Laboratory Medicine series will serve as an introduction to clinical mass spectrometry. (myadlm.org)

2008) concluded that the amount of atrazine applied to the fields by an agricultural worker is likely to provide a valid surrogate of atrazine exposure in epidemiologic studies. (who.int)

Meteorite impacts have caused catastrophic perturbations to the global environment and mass extinctions throughout the Earth's history. (nature.com)
Deep-sea sediments, however, should preserve ejecta from both oceanic and on-land impacts as their slow deposition rate minimises dilution of impactor debris, especially in settings deeper than the carbonate compensation depth. (nature.com)

Anatomy1

Chemicals and Drugs6

Analytical, Diagnostic and Therapeutic Techniques and Equipment15

Disciplines and Occupations1

Information Science1

Health Care2

Tandem mass spectro5

Chromatography13

Inductively6

Time-of-flight ma1

Quantify3

IDMS1

Stable6

Quantification3

Analyte9

Determination2

Urine1

Radioactive3

Employs1

Elemental1

Fractionation2

Ratios3

Metrological1

Quantitative1

Methods6

Isotopic3

Intensities1

Metabolites1

Measurement4

Method10

Concentrations4

Sediment1

Deuterium5

Analytes4

Inorganic1

Equilibrium1

Certified reference1

Analysis3

Sodium1

Potassium1

Detection3

Rapid1

Characterization1

Triple Quadrupole1

Chemistry1

Samples1

Ions2

Biological1

Composition2

Commonly1

Peptide2

Penetration1

Sterols2

Bile acids1

Sample3

Analyses1

Data1

Fluid1

Technique1

Laboratory2

Exposure1

Impacts2