TY - JOUR. T1 - Feasibility of membrane inlet mass spectrometry for on-site screening of volatile monoterpenes and monoterpene alcohols in forest soil atmosphere. AU - Ketola, Raimo A.. AU - Kiuru, Jari. AU - Kotiaho, Tapio. AU - Kitunen, Veikko. AU - Smolander, Aino. PY - 2011. Y1 - 2011. N2 - Volatile monoterpenes and monoterpene alcohols exist in the forest soil atmosphere and they may play an important role in controlling microbial processes related to C and N cycling in boreal forest soils. Therefore, information is needed about their actual concentrations in the soil atmosphere. Here, we developed and applied membrane inlet mass spectrometry (MIMS) with a simple sampling probe for an on-site determination of the most common monoterpenes and monoterpene alcohols in the forest soil atmosphere. The MIMS method was also compared with a chamber method for collection samples into sorbent tubes and an off-line static headspace GC-FID analysis. The sampling principles of the methods are different: ...
TY - JOUR. T1 - Temperature Programmed Desorption for Membrane Inlet Mass Spectrometry. AU - Ketola, Raimo. AU - Grøn, Christian. AU - Lauritsen, Frants Roager PY - 1998. Y1 - 1998. U2 - 10.1002/(SICI)1097-0231(19980630)12:12,773::AID-RCM231,3.0.CO;2-D. DO - 10.1002/(SICI)1097-0231(19980630)12:12,773::AID-RCM231,3.0.CO;2-D. M3 - Journal article. VL - 12. SP - 773. EP - 778. JO - Rapid Communications in Mass Spectrometry. JF - Rapid Communications in Mass Spectrometry. SN - 0951-4198. ER - ...
Article Membrane inlet mass spectrometry method (REOX/MIMS) to measure 15N-nitrate in isotope-enrichment experiments. Using15N stable isotope as a tracer to ...
Persistence Market Research has studied the overall performance of the global liquid chromatography-mass spectroscopy market and have observed that the market is likely to show significant growth owing to a rising demand for liquid chromatography-mass spectroscopy systems across various applications.
The standard atomic weight (or atomic weight) scale has traditionally been a relative value, that is without a unit, with the first relative atomic mass basis suggested by John Dalton in 1803 as 1H.[8] Despite the initial mass of 1H being used as the natural unit for relative atomic mass, it was suggested by Wilhelm Ostwald that relative atomic mass would be best expressed in terms of units of 1/16 mass of oxygen (1903). This evaluation was made prior to the discovery of the existence of elemental isotopes, which occurred in 1912.[8]. The discovery of isotopic oxygen in 1929 led to a divergence in relative atomic mass representation, with isotopically weighted oxygen (i.e., naturally occurring oxygen relative atomic mass) given a value of exactly 16 atomic mass units (amu) in chemistry, while pure 16O (oxygen-16) was given the mass value of exactly 16 amu in physics. The divergence of these values could result in errors in computations, and was unwieldy. The chemistry amu, based on the relative ...
HR Institute of Forensic Science Research & Training (REGD.) - Service Provider of Training On Mass Spectrometry based in Delhi, India
TY - JOUR. T1 - Determination of active hydrogen in organic compounds by electron‐impact mass spectrometry. AU - Dinya, Z.. AU - Lipták, Miklós. AU - Szabó, Pál. AU - Sztaricskai, F.. AU - Vékey, K.. PY - 1992. Y1 - 1992. N2 - We report here detailed studies of Bose et al.s (J. Org. Chem. 47, 4008 (1982)) simple method for obtaining electron‐impact (EI) mass spectra from non‐volatile and/or thermolabile organic compounds by using ammonium salts. Good quality mass spectra can be obtained by mixing the analyte with different ammonium salts (mainly with NH4Cl) in a given ratio, the mixture being introduced through a conventonal direct probe. A wide variety of ammonium salts has been used to study the effect of the anion and to determine the optimum analyte:NH4X ratio and the other experimental parameters (i.e., electron energy, source temperature etc). A very simple and cheap means of determination of active hydrogen in hydroxyl, carboxyl, sulfhydryl, amino and amido etc groups by EI ...
TY - JOUR. T1 - Ovarian Cancer Identification Based on Dimensionality Reduction for High-Throughput Mass Spectrometry Data. AU - Yu, JS. AU - Ongarello, S. AU - Fiedler, R. AU - Chen, RW. AU - Toffolo, G. AU - Trajanoski, Zlatko. AU - Cobelli, C. N1 - PMID:1578749. PY - 2005. Y1 - 2005. M3 - Article. SP - 2200. EP - 2209. JO - Bioinformatics. JF - Bioinformatics. SN - 1367-4803. ER - ...
A comprehensive Collision Cross Section (CCS) library was obtained via Travelling Wave Ion Guide mobility measurements through direct infusion (DI). The library consists of CCS and Mass Spectral (MS) data in negative and positive ElectroSpray Ionisation (ESI) mode for 463 and 479 endogenous metabolites, respectively. For both ionisation modes combined, TWCCSN2 data were obtained for 542 non-redundant metabolites. These data were acquired on two different ion mobility enabled orthogonal acceleration QToF MS systems in two different laboratories, with the majority of the resulting TWCCSN2 values (from detected compounds) found to be within 1% of one another. Validation of these results against two independent, external TWCCSN2 data sources and predicted TWCCSN2 values indicated to be within 1-2% of these other values. The same metabolites were then analysed using a rapid reversed-phase ultra (high) performance liquid chromatographic (U(H)PLC) separation combined with IM and MS (IM-MS) thus ...
Glycans are compounds that consist of a large number of monosaccharides. Glycans can be homopolymers or heteropolymers of monosaccharide residues and can either be linear or branched. Glycans are found on the exterior surface of cells and can be found attached to proteins as in glycoproteins and proteoglycans. In glycan analysis which seeks to explore the structure and functions of various glycans, high-resolution mass spectrometry (MS) and high-performance liquid chromatography (HPLC) are commonly used.. Mass spectrometry (MS) offers high sensitivity and addresses the most frequent biological issues hence it is a valuable tool for the structural characterization of carbohydrates. Oligosaccharide structures can be explained through mass spectrometry and chromatographic separation derivatization. Some of the techniques used for mass spectrometry are Gas Chromatography coupled to Mass Spectrometry (GC/MS), Liquid Chromatography with Mass Spectrometry (LC/MS), Ion mobility-mass spectrometry (IM-MS) ...
View detailed Table of Content here - https://www.marketsandmarkets.com/Market-Reports/mass-spectrometry-market-437.html. The increasing spending on pharmaceutical R&D across the globe, government regulations on drug safety, growing focus on the quality of food products, and technological advancements in mass spectrometers are the key drivers of the mass spectrometry market. Government initiatives for pollution control and environmental testing and an increase in crude and shale gas production are also supporting the growth of this market.. Hybrid mass spectrometers are estimated to account for the largest share of the mass spectrometry platform market in 2019. The mass spectrometry market is segmented on the platform into hybrid mass spectrometry, single mass spectrometry, and other platforms. The hybrid mass spectrometry segment is further divided into triple quadrupole, quadrupole TOF, and Fourier transform mass spectrometry devices, while the single mass spectrometry segment includes single ...
In physics and chemistry, the atomic mass constant, mu, is one twelfth of the mass of an unbound atom of carbon-12 at rest and in its ground state. It serves to define the atomic mass unit and is, by definition, equal to 1 u. The CODATA recommended value is 6973166053904000000♠1.660539040(20)×10−27 kg. In practice, the atomic mass constant is determined as the ratio of the electron rest mass me to the electron relative atomic mass Ar(e) (that is, the mass of the electron on a scale where 12C = 12). The relative atomic mass of the electron can be measured in cyclotron experiments, while the rest mass of the electron can be derived from other physical constants. m u = m e A r ( e ) = 2 R ∞ h A r ( e ) c α 2 {\displaystyle m_{\rm {u}}={\frac {m_{\rm {e}}}{A_{\rm {r}}({\rm {e}})}}={\frac {2R_{\infty }h}{A_{\rm {r}}({\rm {e}})c\alpha ^{2}}}} The current uncertainty in the value of the atomic mass constant - one part in 20 million - is almost entirely due to the uncertainty in the value of the ...
The Year of Education is a joint initiative between separationsNOW and Chromedia. Read more about Chromedia and subscribe Free, Live and Interactive Educational Webinar Sports Drug Testing Chromatography and Mass Spectrometry-Based Approaches This webinar has been broadcast and is now available on demand. Professor Mario Thevis discusses the...
The Year of Education is a joint initiative between separationsNOW and Chromedia. Read more about Chromedia and subscribe Free, Live and Interactive Educational Webinar Sports Drug Testing Chromatography and Mass Spectrometry-Based Approaches This webinar has been broadcast and is now available on demand. Professor Mario Thevis discusses the...
Article Identification of compounds in water by high resolution mass spectrometry. A chemical manufacturer for the rubber and plastics industries used over 100 chemicals for syntheses. For at least 30 years, some fractions of these chemicals, synthes...
Biotech Support Group to exhibit at the 67th ASMS Conference on Mass Spectrometry & Allied Topics. Biotech Support Group will exhibit at the annual ASMS Conference, June 2-6, 2019 in Atlanta, GA. The American Society for Mass Spectrometry (ASMS) was formed in 1969 to promote and disseminate knowledge of mass spectrometry and allied topics. - PR12768157
The article evaluated the degradation of the captopril in aqueous solution after ozonation and chlorination. The process was continuously monitored focusing on the identification, mass spectrometry and elucidation of its by-products by applying direct infusion and high performance liquid chromatography, electrospray ionization high resolution mass spectrometry, in the negative ion mode. The cytotoxicity of its by-products solutions were evaluated with 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. It was observed through that after 30 min of ozonation and chlorination, there was complete oxidation of captopril, i.e., 100% removal efficiency. At these conditions, the rate of mineralization, by total organic carbon, was only 7.63% for ozonation and 6.40% for chlorination, evidencing the formation of degradation by-products. Ten captopril by-products were identified and their respective chemical structures elucidations are proposed. The treated samples and their by-products
This volume explores state-of-the-art mass spectrometric techniques. It focuses on liquid chromatography/mass spectrometry/mass spectrometry and time-of-flight/mass spectrometry to determine emerging contaminants, such as pharmaceuticals, hormones, pesticides, surfactants and unknown natural products.
ePIC (electronic Publication Information Center) is the official repository for publications and presentations of Alfred Wegener Institute for Polar and Marine Research (AWI)
Touch spray mass spectrometry using medical swabs is an ambient ionization technique (ionization of unprocessed sample in the open air) that has potential intraoperative application in quickly ide ...
ISMAS organizes Workshops on Mass Spectrometry at Research Institutes and Universities in different parts of India. These Workshops are aimed at introducing the subject of Mass Spectrometry to novices, updating the Mass Spectrometrists with the latest developments in the field, exposing the participants to innumerable applications of Mass Spectrometry and providing a common forum for discussing the day-to-day problems when working with a Mass Spectrometer. The programme of these Workshops consists of Tutorials, Panel Discussions, Research Scholar Presentations, Poster Presentations and Invited Lectures. The lectures include fundamentals of Mass Spectrometry, qualitative and quantitative aspects and data interpretation, maintenance of Mass Spectrometers, selection of a mass spectrometer, applications in various branches of science as well as recent advances in Mass Spectrometry. The lectures are supplemented by (i) Open-forum discussions on the experiences gained by the Resource Persons (faculty) ...
The Journal of the American Society for Mass Spectrometry presents research papers covering all aspects of mass spectrometry, incorporating coverage of fields of scientific inquiry in which mass spectrometry can play a role.. Comprehensive in scope, the journal publishes papers on both fundamentals and applications of mass spectrometry. Fundamental subjects include instrumentation principles, design, and demonstration, structures and chemical properties of gas-phase ions, studies of thermodynamic properties, ion spectroscopy, chemical kinetics, mechanisms of ionization, theories of ion fragmentation, cluster ions, and potential energy surfaces. In addition to full papers, the journal offers Communications, Application Notes, and Accounts and Perspectives. All papers should describe new mass spectrometry science. Reports of applications that utilize standard mass spectrometry approaches should be sent to application journals.. 2015 Impact Factor: 3.031. ...
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Browse more than 73 market data tables with 17 figures spread through 199 pages and in-depth TOC on Mass Spectrometry Market.. http://www.marketsandmarkets.com/Market-Reports/mass-spectrometry-market-437.html. Early buyers will receive 10% customization on this report.. This report covers the definition, description, and forecast of the mass spectrometry market in terms of technologies and applications. Based on technologies, the mass spectrometry market comprises Tandem LC/MS, LC/MS-Time of Flight, MALDI-TOF, Single Quadrupole, Fourier Transform MS, Gas Chromatography/MS, and others. The applications market is categorized into pharmaceuticals, biotechnology, industrial chemistry, environmental testing, food and beverage testing, and others.. Over the years, the demand for mass spectrometry has increased significantly owing to the increasing use of mass spectrometry technologies to address the growing concerns in food safety and the increasing number of government funds and spending on ...
Our patented, chip-based miniaturised mass spectrometry technology enables analytical detection at the point-of-need in laboratories or bioprocessing facilities
Pyrolysis and mass spectrometry studies of meteoritic organic matter Mass Spectrometry Reviews , 2012, 31 , 560-569 M.A. Sephton Abstract Meteorites are fragments of extraterrestrial materials that fall to the Earths surface. The carbon-rich meteorites are derived from ancient asteroids that have remained relatively unprocessed since the...
A large proportion of polar anthropogenic compounds routinely released into the environment comprises homologue series, i.e., sets of chemicals differing in a repeating chemical unit. Using analytical techniques such as liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS), these compounds are readily measurable as signal sets with characteristic differences in mass and typically retention time. However, and despite such distinct characteristics, no computational approach for the direct, simultaneous and untargeted detection of all such signal sets comprising both LC and HRMS information has to date been presented. A fast two-staged approach has been developed to extract LC-HRMS signal patterns which can be indicative of homologous analytes. In a first stage, a k-d tree representation of picked LC-HRMS peaks is used to extract all feasible 3-tuples of peaks with restrictions in, e.g., mass defect differences. A second stage then recombines these 3-tuples to larger series tuples
The combination of stable isotope labelling with direct infusion ion mobility mass spectrometry (IM-MS) enabled qualitative and quantitative monitoring of biocatalytic reactions with reduced analysis times, enhanced sensitivity and μL-level assay volumes. The new approach was demonstrated by applying to both lipase and monooxygenase enzymes, including multi-substrate screening ...
TY - JOUR. T1 - Monitoring organic compounds in aqueous solution by rotating ball inlet mass spectrometry with continuous wave infrared laser desorption. AU - Schmidt, E.N.. AU - Ørsnes, H.. AU - Graf, T.. AU - Christensen, T.. AU - Degn, H.. PY - 2001. Y1 - 2001. U2 - 10.1016/S0925-4005(01)00649-9. DO - 10.1016/S0925-4005(01)00649-9. M3 - Journal article. VL - 76. SP - 411. EP - 418. JO - Sensors and Actuators B: Chemical. JF - Sensors and Actuators B: Chemical. SN - 0925-4005. ER - ...
Manufacturer of Liquid Chromatography Mass Spectrometry - LCMS QQQ 6460 Mass Spectrometer, CAH Mass Solution offered by Trivitron Healthcare Pvt. Ltd., Chennai, Tamil Nadu.
Laser isotope mass spectrometry is the next-generation technology for measuring environmental isotopes, and the Groundwater Education Investment Fund (GEIF) has invested in a suite of instruments to enable state-of-art research capabilities for groundwater research in Australia.. The ability to measure oxygen and hydrogen isotopes in liquid water and water vapour is of great value in both field and laboratory settings.. In the field, water vapour analyses help quantify the water budget as they can constrain water loss incurred due to evapotranspiration from vegetation. In the laboratory, the ancient pore water can be measured in aquitard material and can characterise water movement in aquitards through the vapour equilibrium technique.. Laser isotope mass spectrometry can also be used for isotope analysis of the carbon contained in dissolved organic and inorganic carbon and gaseous methane.. One of the main benefits of a method for the routine measurement of liquid water samples by isotope mass ...
Learn about Agilent׷ liquid chromatography/mass spectrometry (LC/MS). Agilent LC/MS enables a wide array of applications by combining sample preparation, liquid chromatography (LC), mass spectrometry (MS), and dedicated software tools like compound databases and libraries.
Background In recent years, several mass spectrometry-based omics technologies emerged to investigate qualitative and quantitative changes within thousands of biologically active components such as proteins, lipids and metabolites. The research enabled through these methods potentially contributes to the diagnosis and pathophysiology of human diseases as well as to the clarification of structures and interactions between biomolecules. Simultaneously, technological advances in the field of mass spectrometry leading to an ever increasing amount of data, demand high standards in efficiency, accuracy and reproducibility of potential analysis software. Results This article presents the current state and ongoing developments in OpenMS, a versatile open-source framework aimed at enabling reproducible analyses of high-throughput mass spectrometry data. It provides implementations of frequently occurring processing operations on MS data through a clean application programming interface in C++ and Python. ...
Been many years since I took general and org chem and am currently reading general chem textbook as refresher. Came across defintion of amu (atomic mass unit). Text says that the mass of the carbon-12 atom is defined to be exactly 12 amu. However, a couple of pages over, I read that the mass of the proton is about 1.007 amu, and the mass of the neutron is about 1.009 amu. Add up the masses of 6 protons and 6 neutrons for the carbon-12 atom, and you come up with more than 12 amu. I cant resolve this apparent discrepancy. Ive consulted other texts, etc. Does some type of relativistic effect bear on this situation? In other words, does, for example, an isolated proton have a mass of 1.007 amu, but then when part of an atom have a slightly different mass because of some relativistic effect? HELP ...
Characterisation of stereoisomeric α-methylene-γ-lactone furanosidic derivatives by direct chemical ionisation mass spectrometry and liquid secondary ion mass sepctrometry with tandem mass spectrometry ...
Abstract : Butylatedhydroxytoluene (BHT) and 4-methoxyphenol (4-MP) are phenol derivatives that are generally knownfor their antioxidant properties and depigmenting activities. The aim of this study was to evaluate the impact ofbiofield energy treatment on the isotopic abundance in BHT and 4-MP using gas chromatography-mass spectrometry(GC-MS). BHT and 4-MP samples were divided into two parts: control and treated. The control group remaineduntreated while the treated group was subjected to Mr. Trivedis biofield treatment. Control and treated sampleswere characterized using GC-MS. The GC-MS data revealed that the isotopic abundance ratio of 13C/12C or 2H/1H(PM+1)/PM and 18O/16O (PM+2)/PM increased significantly in treated BHT and 4-MP (where PM- primary molecule,PM+1- isotopic molecule either for 13C or 2H and PM+2 is the isotopic molecule for 18O). The isotopic abundance ratioof (PM+1)/PM in the treated BHT and 4-MP was increased up to 181.27% and 380.73% respectively as comparedto their ...
The characterization of protein stability changes and protein-ligand interactions on the proteomic scale is important for understanding the biology of cellular processes. The identification and quantification of protein-ligand binding affinities is critical for disease state analyses and drug discovery. A mass spectrometry-based technique, Stability of Proteins from Rates of Oxidation (SPROX), has been established for the thermodynamic analysis of protein stability and protein-ligand interactions. In the first part of this dissertation, a previously published iTRAQ-SPROX protocol is improved by incorporating a filter assisted sample preparation (FASP) protocol to significantly reduce sample loss during the experiment. Also, in order to eliminate methionine as a potential contaminant that can cause signal suppression during LC-MS/MS analysis, TCEP•HCl is used to quench the H2O2 oxidation instead of methionine. This avoids the potential reaction between the free methionine and the iTRAQ ...
Given the wide diversity in applications of biological mass spectrometry, custom data analyses are often needed to fully interpret the results of an experiment. Such bioinformatics scripts necessarily include similar basic functionality to read mass spectral data from standard file formats, process it, and visualize it. Rather than having to reimplement this functionality, to facilitate this task, spectrum_utils is a Python package for mass spectrometry data processing and visualization. Its high-level functionality enables developers to quickly prototype ideas for computational mass spectrometry projects in only a few lines of code. Notably, the data processing functionality is highly optimized for computational efficiency to be able to deal with the large volumes of data that are generated during mass spectrometry experiments. The visualization functionality makes it possible to easily produce publication-quality figures as well as interactive spectrum plots for inclusion on web pages. spectrum_utils
ReportsnReports.com adds Mass Spectrometry Market - by Technology (Tandem LC - MS/ Quadrupole/ ICP - MS/ Gas Chromatography - MS/ TOF - MS/ MALDI -TOF/ Fourier Transform - MS) & by Application (Pharmaceutical/ Biotechnology/ Environment/ Food & Beverages) - Global Trends & Forecast to 2018 report to its research database.. Over the years, the mass spectrometry market-comprising of instruments, consumables, and services-has witnessed various technological advancements. These advancements have led to a growth in the number of mass spectrometry applications. Some of the applications using mass spectrometry are drug discovery and development, metabolomics, biomarkers, and diagnostics. However, the high cost of instruments and the need for skilled professionals to operate these highly sophisticated systems are factors that are hindering the market.. The MALDI-TOF segment is one of the fastest-growing segments in the mass spectrometry market, since MALDI-based technologies are expected to find ...
The mass spectrometry platform of the CPF is the cancer-focused component of the Biomedical Mass Spectrometry (BioMS) Center, a University of Pittsburgh-wide shared resource located in the Biomedical Science Tower 3 on the Oakland campus. This facility was designed and renovated as a dedicated, state-of-the-art mass spectrometry center, to advance the use and application of mass spectrometry in basic and/or translational research at all levels, from first-time users to experts in the field. The CPF/BioMS Center currently includes twelve modern mass spectrometers that support a wide range of analytical capabilities.. Learn more about the mass spectrometry resources and equipment available to Hillman investigators through the CPF/BioMS Center.. ...
Abstract : 2-Aminopyridine (2-AP) and 2,6-diaminopyridine (2,6-DAP) are two derivatives of aminopyridines that act as animportant organic intermediates, mostly used in medicines, dyes and organic sensors. The aim of the study was to evaluate theimpact of biofield energy treatment on isotopic abundance ratios of 2H/1H, 13C/12C, or 15N/14N, in aminopyridine derivativesusing gas chromatography-mass spectrometry (GC-MS). The 2-AP and 2,6-DAP samples were divided into two parts: controland treated. The control sample remained as untreated, while the treated sample was further divided into four groups as T1, T2,T3, and T4. The treated group was subjected to Mr. Trivedis biofield energy treatment. The GC-MS spectra of 2-AP and 2,6-DAP showed five and six m/z peaks respectively due to the molecular ion peak and fragmented peaks of aminopyridinederivatives. The isotopic abundance ratio of 2H/1H, 13C/12C, or 15N/14N were calculated for both the derivatives and significantalteration was found in the ...
one_half]. Mass spectrometry is an analytical technique vastly used in chemistry, biotechnology, food and safety monitoring, pharmaceutics, genomics, proteomics, and many others. Its academic and economic importance in the UK is thoroughly documented by the British Mass Spectrometry Society (www.bmss.org.uk). The global market amounts to £ 2.5 billion per year. Small mass spectrometers are available, however all in the low range of mass resolution ∆m/m∈10-3-10-4. The mass resolution of the Geonium Chip is given by the cyclotron resonance ∆ωp/ωp, which we aim at 10-7 or above, thus orders of magnitude better than other small mass spectrometers.. The Geonium Chip technology will deliver a cutting-edge mass spectrometry technology at a much lower cost and size than conventional high-end FT-ICR mass spectrometers, which require a superconducting solenoid. The key factor is the achievement of a homogeneous magnetic field at the position of the trapped ions. This can be done with a local ...
Detail záznamu - Tandem mass spectrometry identification and LC-MS quantification of intact cytokinin nucleotides in K-562 human leukemia cells - Detail záznamu - Knihovna Akademie věd České republiky
Wenchao Zhang, Junil Chang, Zhentian Lei, David Huhman, Lloyd W. Sumner, and Patrick X. Zhao. Plant Biology Division, The Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK 73401, USA. Accurate and automated metabolite-associated chromatograph peak feature extraction, annotation, alignment, and quantification are critical yet challenging analysis steps in large-scale liquid chromatography/mass spectrometry (LC/MS)-based untargeted metabolomics and metabolite identification.. We developed a novel LC/MS data processing and analysis platform, MET-COFEA (METabolite COmpound Feature Extraction and Annotation). MET-COFEA detects and clusters chromatograph peak features for each metabolite compound by first comprehensively evaluating retention time and peak shape criteria and then annotating the associations between each peaks observed m/z value with the corresponding metabolite compounds molecular mass. MET-COFEA integrates a series of innovative approaches, including novel mass ...
Mass spectrometry is a multidisciplinary field that has emerged as an indispensable analytical method due to its high sensitivity, universality and specificity. The technique plays vital role in several scientific areas such as chemistry, physics, nuclear technology, biology, material science, forensic science, archaeology, etc. The list of applications continues to grow day by day. In order to promote the activities of Mass spectrometry in India, ISMAS was formed in 1978 during a meeting of mass spectrometrists at Bhabha Atomic Research Centre. The Life-members include mass spectrometrists from research institutes, universities and industry from India as well as abroad. For nearly last four decades, ISMAS has been playing a key role in popularizing mass spectrometry in India by organizing international/national symposia, workshops, theme based meetings on mass spectrometry, recognizing achievements in mass spectrometry through ISMAS awards program etc. A recent addition to the activities of ...
In the article below, Jie Ding, associate director of development and validation at the PPD® Laboratories GMP lab, discusses liquid chromatography-mass spectrometry in drug discovery and development.. In a drug stability program, high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection remains the most common and cost-effective methodology. Even so, UV detection has its own limitations, including poor sensitivity for non-UV absorbing compounds and lack of specificity. These shortcomings in turn have motivated scientists to pursue other alternatives. Mass spectrometry detection is such a candidate. Mass spectrometry (MS) is a detection method that measures the mass-to-charge ratio (m/z) of a compound. Compared to UV detection, MS offers higher sensitivity, better detection limits, and the ability to provide additional molecular weight information-making it an information rich detection method.. Over the last two decades, MS has become an important analytical tool to ...
A Senior Research Scientist position focusing on quantitative proteomics is available at the Mass Spectrometry Facility at the University of Massachusetts Medical School. Affiliated with the Department of Biochemistry and Molecular Pharmacology, the Facility supports projects in basic and translational science across a diverse range of applications in proteomics, structural biology, metabolomics, small molecule quantitation, and mass spectrometry imaging. There are nine mass spectrometry platforms including four Orbitraps (Thermo Fusion Lumos w/ ETD and FAIMS, Q Exactive HF-X, Q Exactive and Orbitrap Velos Pro), a Q-TOF (Waters Synapt G2-Si) and two triple quadrupoles (Waters Xevo TQ-XS and Thermo TSQ Quantiva), all located in a spacious 5,000 sq. ft facility. This is a unique growth opportunity for an enthusiastic self-starter that will contribute to a wide and diverse range of projects both within the University of Massachusetts and to the external scientific community at large. The individual ...
Boerboom, A. J. H. (1985). Pyrolysis mass spectrometry. In S Facchetti (Ed.), Mass Spectrometry of Large Molecules :Lectures of a Course held at the Joint Research Centre, Ispra, Italy, 5-9 September 1983 (pp. 265-281). Amsterdam: Elsevier ...
TY - JOUR. T1 - A membrane inlet mass spectrometry system for noble gases at natural abundances in gas and water samples. AU - Visser, Ate. AU - Singleton, Michael J.. AU - Hillegonds, Darren J.. AU - Velsko, Carol A.. AU - Moran, Jean E.. AU - Esser, Bradley K.. PY - 2013/11/15. Y1 - 2013/11/15. N2 - Rationale Noble gases dissolved in groundwater can reveal paleotemperatures, recharge conditions, and precise travel times. The collection and analysis of noble gas samples are cumbersome, involving noble gas purification, cryogenic separation and static mass spectrometry. A quicker and more efficient sample analysis method is required for introduced tracer studies and laboratory experiments. Methods A Noble Gas Membrane Inlet Mass Spectrometry (NG-MIMS) system was developed to measure noble gases at natural abundances in gas and water samples. The NG-MIMS system consists of a membrane inlet, a dry-ice water trap, a carbon-dioxide trap, two getters, a gate valve, a turbomolecular pump and a ...
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TY - JOUR. T1 - Chemical reactions in fast atom bombardment mass spectrometry. AU - Vékey, K.. AU - Zerilli, Luigi F.. PY - 1991. Y1 - 1991. N2 - Examples of various chemical reactions occurring in the matrix or in the selvedge region in fast atom bombardment (FAB) mass spectrometry are discussed. These are categorized as oxidations and reductions; substitutions; clusterings and additions; and sample decomposition or transformation. Some reactions observed showed significant time behaviour and in one case it was possible to determine rate constants. These data suggest that chemical reactions can be accelerated significantly by fast atom bombardment.. AB - Examples of various chemical reactions occurring in the matrix or in the selvedge region in fast atom bombardment (FAB) mass spectrometry are discussed. These are categorized as oxidations and reductions; substitutions; clusterings and additions; and sample decomposition or transformation. Some reactions observed showed significant time ...
TY - JOUR. T1 - Detection of Adriamycin-DNA adducts by accelerator mass spectrometry at clinically relevant Adriamycin concentrations. AU - Coldwell, Kate E.. AU - Cutts, Suzanne M.. AU - Ognibene, Ted J.. AU - Henderson, Paul. AU - Phillips, Don R.. PY - 2008. Y1 - 2008. N2 - Limited sensitivity of existing assays has prevented investigation of whether Adriamycin-DNA adducts are involved in the anti-tumour potential of Adriamycin. Previous detection has achieved a sensitivity of a few Adriamycin-DNA adducts/104 bp DNA, but has required the use of supra-clinical drug concentrations. This work sought to measure Adriamycin-DNA adducts at sub-micromolar doses using accelerator mass spectrometry (AMS), a technique with origins in geochemistry for radiocarbon dating. We have used conditions previously validated (by less sensitive decay counting) to extract [14C]Adriamycin-DNA adducts from cells and adapted the methodology to AMS detection. Here we show the first direct evidence of Adriamycin-DNA ...
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TY - JOUR. T1 - Capillary electrophoresis-mass spectrometry for the analysis of amino acids. AU - Iavarone, Federica. AU - Desiderio, Claudia. AU - Rossetti, Diana Valeria. AU - Messana, Irene. AU - Castagnola, Massimo. PY - 2010. Y1 - 2010. N2 - In this review, the recent contribution of CE-MS technology to the analysis of amino acids, as well as the advantages of the hyphenation and the technologies involved in the instrumental coupling are reported. Different sections are dedicated to the recent contributions of CE-MS to the analysis of protein amino acids and their post-translational modifications, such as phosphorylation and sulfation. CE-MS analysis of some amino acid derivatives, such as the free methylated-derivatives of arginine is also discussed. A section is specifically devoted to the CE-MS applications in the field of chiral separation of D-and L-amino acid enantiomers.. AB - In this review, the recent contribution of CE-MS technology to the analysis of amino acids, as well as the ...
TY - JOUR. T1 - Peptide identifications and false discovery rates using different mass spectrometry platforms. AU - Anapindi, Krishna D.B.. AU - Romanova, Elena V.. AU - Southey, Bruce R.. AU - Sweedler, Jonathan V.. N1 - Funding Information: The project described was supported by Award no. P30 DA018310 from the National Institute on Drug Abuse , Award no. R01 NS031609 from the National Institute of Neurological Disorders and Stroke , and Award no. CHE-16-06791 from the National Science Foundation . The content is solely the responsibility of the authors and does not necessarily represent the official views of the funding agencies. Appendix A PY - 2018/5/15. Y1 - 2018/5/15. N2 - Characterization of endogenous neuropeptides produced from post-translational proteolytic processing of precursor proteins is a demanding task. A variety of complex prohormone processing steps generate molecular diversity from neuropeptide prohormones, making in silico neuropeptide discovery difficult. In addition, the ...
Capillary electrophoresis-mass spectrometry (CE-MS) is a hyphenated technique that combines the advantages like low sample consumption, high separation efficiency, short analytical time in CE and high sensitivity, powerful molecular structure elucidation in MS. Polyimide-coated fused silica capillary has become the most dominant capillary for CE, but it suffers from swelling and aminolysis of polyimide coating when treated with organic solvents and alkaline buffer in the CE-MS interface in which
Mass spectroscopy is increasingly used for measuring the presence and amounts of substances in samples, with applications in food, security, health and safety industries and is considered an excellent measurement tool. One of the methods used to identify multiple compounds in a sample is isotope dilution. However, this method does not account for the sample changes during the analysis and composition changes must be determined mathematically or by conducting multiple experiments. Due to this complexity, uptake of this advanced calibration approach is slow. Current algorithms to address simultaneous compound formation and degradation using multiple spiking isotope dilution mass spectrometry are extremely complex and do not result in explicit results nor reliable estimates of uncertainty in those results. Many algorithms give identical numerical results for the initial amount of substances in the sample, but the coefficients that describe the changes during the analysis differ.. There is a demand ...
TY - JOUR. T1 - A liquid chromatography with tandem mass spectrometry-based proteomic analysis of cells cultured in DMEM 10% FBS and chemically defined medium using human adipose-derived mesenchymal stem cells. AU - Nakashima, Yoshiki. AU - Nahar, Saifun. AU - Miyagi-Shiohira, Chika. AU - Kinjo, Takao. AU - Kobayashi, Naoya. AU - Saitoh, Issei. AU - Watanabe, Masami. AU - Fujita, Jiro. AU - Noguchi, Hirofumi. PY - 2018/7/13. Y1 - 2018/7/13. N2 - Human adipose-derived mesenchymal stem cells (hADSCs) are representative cell sources for cell therapy. Classically, Dulbeccos Modified Eagles medium (DMEM) containing 10% fetal bovine serum (FBS) has been used as culture medium for hADSCs. A chemically defined medium (CDM) containing no heterologous animal components has recently been used to produce therapeutic hADSCs. However, how the culture environment using a medium without FBS affects the protein expression of hADSC is unclear. We subjected hADSCs cultured in CDM and DMEM (10% FBS) to a protein ...
Abstract :The extraction, separation and purification of flavonoids from Aurea Helianthus were performed using various organic solvents and gradient elution methods. Ultraviolet spectrophotometry and high performance liquid chromatography-mass spectrometry were used to analyze flavonoids. Results:UV-Vis spectrophotometer UV 2450 (SHIMADZU) was used to preliminarily identify the content of flavonoids in the extracts of Aurea Helianthus3 flavonoid content in the ethyl acetate extract was the highest ,48.3±0.3%.There was a good linear relationship between 0.004 and 0.024 mg/ml (R2 = 0.998).Ethyl acetate extract was used as the test object for high performance liquid chromatography-mass spectrometry analysis.In the linear range 10.0-240μg,good precision and reproducibility, stable within 6 hours.The average recoveries of quercetin,Hyperoside, and rutin were 105.32%, 102.25%, and 103.14%.The content of rutin in the gradient elution (EtOAc:MeOH=4:1) was 42.8±0.3%, and the content of hyperin and ...
TY - GEN. T1 - APPLICATIONS OF LASER DESORPTION MASS SPECTROMETRY.. AU - Cotter, Robert J.. AU - Tabet, Jean Claude. AU - van Breemen, Richard. PY - 1984. Y1 - 1984. N2 - The laser desorption technique can be used for the mass spectral analysis of nonvolatile/thermally labile compounds such as peptides, oligosaccharides, glycolipids, etc. In our laboratory a laser desorption time-of-flight mass spectrometer has been used for structural confirmation of several glucuronic acid conjugates, synthesized by an immobilized-enzyme mediated technique. Laser desorption spectra of several small peptides produce both C-terminal and N-terminal fragments. The molecular ions are formed by cationization (alkali ion attachment) and the alakali ion is generally found on the C-terminal fragments, suggesting a ionization/fragmentation scheme similar to that observed by chemical ionization.. AB - The laser desorption technique can be used for the mass spectral analysis of nonvolatile/thermally labile compounds such ...
Hemoglobin (Hb) is a tetrameric noncovalent complex consisting of two alpha- and two beta-globin chains each associated with a heme group. Its exact assembly pathway is a matter of debate. Disorders of hemoglobin are the most common inherited disorders and subsequently the molecule has been extensively studied. This work attempts to further elucidate the structural properties of the hemoglobin tetramer and its components. Gas-phase conformations of hemoglobin tetramers and their constituents were investigated by means of traveling-wave ion mobility mass spectrometry. Sickle (HbS) and normal (HbA) hemoglobin molecules were analyzed to determine whether conformational differences in their quaternary structure could be observed. Rotationally averaged collision cross sections were estimated for tetramer, dimer, apo-, and holo-monomers with reference to a protein standard with known cross sections. Estimates of cross section obtained for the tetramers were compared to values calculated from X-ray ...
Recent advances in phosphopeptide enrichment prior to mass spectrometric analysis show genuine promise for characterization of phosphoproteomes. Tandem mass spectrometry of phosphopeptide ions, using collision-activated dissociation (CAD), often produces product ions dominated by the neutral loss of …
Federal regulations concerning the safety and efficacy of biopharmaceuticals require the implementation of a comprehensive toolbox of physicochemical and biological characterization methods. In order to demonstrate consistent overall structure, even minute differences in primary structure and post‑translational modifications (PTMs) have to be detectable in therapeutic proteins. Because of their remarkable capability of revealing small changes in molecular structure, high performance liquid chromatography (HPLC) and mass spectrometry (MS) rate among the most powerful technologies for comprehensive protein analysis. This article details the potential of both methods with regard to revealing methionine oxidation, a chemical modification that may be induced during downstream processing and storage of biopharmaceuticals. The benefits and limitations of bottom-up, middle-down, and top‑down HPLC-MS analysis will be demonstrated for the detection of oxidation variants in a therapeutic monoclonal antibody
294547663 - EP 0985148 A1 2000-03-15 - NUCLEIC ACID DIAGNOSTICS BASED ON MASS SPECTROMETRY OR MASS SEPARATION AND BASE SPECIFIC CLEAVAGE - [origin: WO9854571A1] A method of detecting a mutation or a difference of one or more nucleotides between a nucleic acid molecule to be tested and a reference nucleic acid molecule, said method comprising subjecting the test nucleic acid molecule to base specific cleavage to generate oligonucleotide fragments, separating the resulting oligonucleotide fragments based on mass by MALDI-ATOF MS and/or other equivalent procedure to produce a fingerprint of then oligonucleotide fragments comprising one or more peaks wherein a peak represents the mass of each fragment and identifying an altered peak relative to a reference nucleic acid molecule subjected to the same procedure wherein the presence of an altered peak is indicative of a difference of one or more nucleotides in said tested nucleic acid molecule.[origin: WO9854571A1] A method of detecting a mutation or a
Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) has become one of the most used tools in mass spectrometry based proteomics. Various algorithms have since been developed to automate the process for modern high-throughput LC-MS/MS experiments. A probability based statistical scoring model for assessing peptide and protein matches in tandem MS database search was derived. The statistical scores in the model represent the probability that a peptide match is a random occurrence based on the number or the total abundance of matched product ions in the experimental spectrum. The model also calculates probability based scores to assess protein matches. Thus the protein scores in the model reflect the significance of protein matches and can be used to differentiate true from random protein matches. The model is sensitive to high mass accuracy and implicitly takes mass accuracy into account during scoring. High mass accuracy will not only reduce false positives, but also improves the
Fingerprint Dive into the research topics of Gel permeation chromatography coupled to fourier transform mass spectrometry for polymer characterization. Together they form a unique fingerprint. ...
Separation and identification of individual congeners requires specialized instrumentation, such as a high resolution GC column coupled to a high resolution mass spectrometer. Analyte types include the congeners of dioxins, furans, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs). These methods may require a screening procedure using low resolution instrumentation prior to an isotope dilution mass spectrometry analysis performed on high resolution instrumentation. Prior to analysis, samples first undergo an extraction process which partitions analytes into an organic solvent compatible with the instrumentation. Example US EPA methods include 1613, 1614, 1668, 8280, 8290, DLM02.2, and TO-9.
TY - JOUR. T1 - A theoretical and mass spectrometry study of the fragmentation of mycosporine-like amino acids. AU - Cardozo, KHM. AU - Vessecchi, R. AU - Carvalho, VM. AU - Pinto, E. AU - Gates, PJ. AU - Colepicolo, P. AU - Galembeck, SE. AU - Lopes, NP. PY - 2008/6/1. Y1 - 2008/6/1. UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-43049164308&partnerID=8YFLogxK. U2 - 10.1016/j.ijms.2008.02.014. DO - 10.1016/j.ijms.2008.02.014. M3 - Article (Academic Journal). VL - 273. SP - 11. EP - 19. JO - International Journal of Mass Spectrometry. JF - International Journal of Mass Spectrometry. SN - 1387-3806. IS - 1-2. ER - ...
Imaging mass spectrometry combines the power of mass spectrometry to identify complex molecules based on mass with sample imaging. Recent advances in secondary ion mass spectrometry have improved sensitivity and spatial resolution, so that these methods have the potential to bridge between high-resolution structures obtained by X-ray crystallography and cyro-electron microscopy and ultrastructure visualized by conventional light microscopy. Following background information on the method and instrumentation, we address the key issue of sample preparation. Because mass spectrometry is performed in high vacuum, it is essential to preserve the lateral organization of the sample while removing bulk water, and this has been a major barrier for applications to biological systems. Furthermore, recent applications of imaging mass spectrometry to cell biology, microbial communities, and biosynthetic pathways are summarized briefly, and studies of biological membrane organization are described in greater ...
Capillary electrophoresis (CE) offers fast and high-resolution separation of charged analytes from small injection volumes. Coupled to mass spectrometry (MS), it represents a powerful analytical technique providing (exact) mass information and enables molecular characterization based on fragmentation. Although hyphenation of CE and MS is not straightforward, much emphasis has been placed on enabling efficient ionization and user-friendly coupling. Though several interfaces are now commercially available, research on more efficient and robust interfacing with nano-electrospray ionization (ESI), matrix-assisted laser desorption/ionization (MALDI) and inductively coupled plasma mass spectrometry (ICP) continues with considerable results. At the same time, CE-MS has been used in many fields, predominantly for the analysis of proteins, peptides and metabolites. This review belongs to a series of regularly published articles, summarizing 248 articles covering the time between June 2016 and May 2018. Latest
Structural characterization of ions in the gas phase is facilitated by measurement of ion collision cross sections (CCS) using techniques such as ion mobility spectrometry. Further information is gained from CCS measurement when comparison is made between measurements and accurately predicted CCSs for model ion structures and the gas in which measurements are made. While diatomic gases, namely molecular nitrogen and air, are being used in CCS measurement with increasingly prevalency, the majority of studies in which measurements are compared to predictions use models in which gas molecules are spherical or non-rotating, which is not necessarily appropriate for diatomic gases. Here, we adapt a momentum transfer based CCS calculation approach to consider rotating, diatomic gas molecule collisions with polyatomic ions, and compare CCS predictions with a diatomic gas molecule to those made with a spherical gas molecular for model spherical ions, tetra-alkylammonium ions, and multiply charged ...
Electrospray ionization with an ultralow flow rate (≤4 nanoliters per minute) was used to directly couple capillary electrophoresis with tandem mass spectrometry for the analysis and identification of biomolecules in mixtures. A Fourier transform mass spectrometer provided full spectra (,30 kilodaltons) at a resolving power of ≈60,000 for injections of 0.7 × 10−18 to 3 × 10−18 mole of 8- to 29-kilodalton proteins with errors of ,1 dalton in molecular mass. Using a crude isolate from human blood, a value of 28,780.6 daltons (calculated, 28,780.4 daltons) was measured for carbonic anhydrase, representing 1 percent by weight of the protein in a single red blood cell. Dissociation of molecular ions from 9 × 10−18 mole of carbonic anhydrase gave nine sequence-specific fragment ions, more data than required for unique retrieval of this enzyme from the protein database.. ...
TY - JOUR. T1 - Mining gene functional networks to improve mass-spectrometry-based protein identification. AU - Ramakrishnan, Smriti R.. AU - Vogel, Christine. AU - Kwon, Taejoon. AU - Penalva, Luiz O. AU - Marcotte, Edward M.. AU - Miranker, Daniel P.. PY - 2009/11/15. Y1 - 2009/11/15. N2 - Motivation: High-throughput protein identification experiments based on tandem mass spectrometry (MS/MS) often suffer from low sensitivity and low-confidence protein identifications. In a typical shotgun proteomics experiment, it is assumed that all proteins are equally likely to be present. However, there is often other evidence to suggest that a protein is present and confidence in individual protein identification can be updated accordingly. Results: We develop a method that analyzes MS/MS experiments in the larger context of the biological processes active in a cell. Our method, MSNet, improves protein identification in shotgun proteomics experiments by considering information on functional associations ...
Part I. Field desorption (FD) mass spectra have been obtained from a series of alkali metal cryptates formed from {2.2.2}-, {2.2.1}- and {2.1.1}-cryptands with Li(+), Na(+) and K(+) salts of Cl(-), Br(-), I(-), OTs(-) and BPh(,4)(-). Stabilities of these complexes under FD conditions are compared with their thermodynamic stabilities in solution. Differences in these stabilities are attributed to the lack of solvation of ions under FD conditions. A marked anion effect is also observed in FD spectra. This effect is correlated with the recombination energy of the released cation and anion in the gaseous state. Part II. Acid phthalates from isomeric alicyclic alcohols have been studied by field desorption (FD) and electron impact (EI) mass spectrometry. Isomeric acid phthalates gave identical FD spectra and EI spectra. The use of these methods for distinguishing stereoisomers of this type thus proved to be unsuccessful. However, the field ionization (FI) spectra of cis- and trans-4-t-butylcyclohexyl
Ion mobility-mass spectrometry (IM-MS) is a rapid, gas-phase separation technique that has become an integral part of the analytical repertoire of techniques for the -omics. This method coupl
Figure 1: Estimation of Ion Competition via Correlated Responsivity Offset in Linear Ion Trap Mass Spectrometry Analysis: Theory and Practical Use in the Analysis of Cyanobacterial Hepatotoxin Microcystin-LR in Extracts of Food Additives
Law, W.S., Huang, P.Y., Li, S.F.Y., Ong, E.S., Ong, C.N., Sethi, S.K., Saw, S. (2009). Combination of1H nuclear magnetic resonance spectroscopy and liquid chromatography/mass spectrometry with pattern recognition techniques for evaluation of metabolic profile associated with albuminuria. Journal of Proteome Research 8 (4) : 1828-1837. [email protected] Repository. https://doi.org/10.1021/ ...
TY - JOUR. T1 - Methods and Algorithms for Quantitative Proteomics by Mass Spectrometry. AU - Matthiesen, Rune. AU - Carvalho, Ana Sofia. PY - 2020/1/1. Y1 - 2020/1/1. N2 - Protein quantitation by mass spectrometry has always been a resourceful technique in protein discovery, and more recently it has leveraged the advent of clinical proteomics. A single mass spectrometry analysis experiment provides identification and quantitation of proteins as well as information on posttranslational modifications landscape. By contrast, protein array technologies are restricted to quantitation of targeted proteins and their modifications. Currently, there are an overwhelming number of quantitative mass spectrometry methods for protein and peptide quantitation. The aim here is to provide an overview of the most common mass spectrometry methods and algorithms used in quantitative proteomics and discuss the computational aspects to obtain reliable quantitative measures of proteins, peptides and their ...
Autor: Manz, Christian; Genre: Hochschulschrift; Titel: Automated Analysis of Complex Carbohydrates via Ion Mobility-Mass Spectrometry
Pre-sputtering before secondary ion mass spectrometry measurement is a well known technique to increase the detection limits of atmospheric gas elements: during a prolonged primary ion bombardment of a clean target a layer on the sample surface and the immersion lens is formed which decreases the re-implantation pr
High surface sensitivity and lateral resolution imaging make time-of-flight secondary ion mass spectrometry (ToF-SIMS) a unique and powerful tool for biological analysis. However, with the leaps forward made in the capabilities of the ToF-SIMS instrumentation, the data being recorded from these instruments has dramatically increased. Unfortunately, with these large, often complex, datasets, a bottleneck appears in their processing and interpretation. Here, an application of peak picking is described and applied to ToF-SIMS images allowing for large compression of data, noise removal and improved contrast, while retaining a high percentage of the original signal. Peak picking is performed to locate peaks within ToF-SIMS data. By using this information, signal arising from the same distribution can be summed and overlapping signals separated. As a result, the data size and complexity can be dramatically reduced. This method also acts as an effective noise filter, discarding unwanted noise from the data
Description of Technique. Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS) is an analytical technique used to obtain elemental and molecular chemical data about surfaces (static SIMS), and detect parts per billion (ppb) concentrations of impurities in semiconductors and metals (dynamic SIMS).
TY - JOUR. T1 - Multi-isotope imaging mass spectrometry reveals slow protein turnover in hair-cell stereocilia. AU - Zhang, Duan Sun. AU - Piazza, Valeria. AU - Perrin, Benjamin J.. AU - Rzadzinska, Agnieszka K.. AU - Poczatek, J. Collin. AU - Wang, Mei. AU - Prosser, Haydn M.. AU - Ervasti, James M.. AU - Corey, David P.. AU - Lechene, Claude P.. PY - 2012/1/26. Y1 - 2012/1/26. N2 - Hair cells of the inner ear are not normally replaced during an animals life, and must continually renew components of their various organelles. Among these are the stereocilia, each with a core of several hundred actin filaments that arise from their apical surfaces and that bear the mechanotransduction apparatus at their tips. Actin turnover in stereocilia has previously been studied by transfecting neonatal rat hair cells in culture with a β-actin-GFP fusion, and evidence was found that actin is replaced, from the top down, in 2-3 days. Overexpression of the actin-binding protein espin causes elongation of ...
An accurate method based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) has been developed for quantitative analysis of calcitonin and insulin in different commercially available pharmaceutical products. Tryptic peptides derived from these polypeptides were chemically modified at their C-terminal lysine-residues with 2-methoxy-4,5-dihydro-imidazole (light tagging) as standard and deuterated 2-methoxy-4,5-dihydro-imidazole (heavy tagging) as internal standard (IS). The heavy modified tryptic peptides (4D-Lys tag), differed by four atomic mass units from the corresponding light labelled counterparts (4H-Lys tag). The normalized peak areas (the ratio between the light and heavy tagged peptides) were used to construct a standard curve to determine the concentration of the analytes. The concentrations of calcitonin and insulin content of the analyzed pharmaceutical products were accurately determined, and less than 5% error was obtained between the ...
In May 2013, an 18-year-old patient arrived at the University of California-San Francisco emergency department in status epilepticus after reportedly taking two blotter papers of lysergic acid diethylamide (LSD). Over the course of his hospital stay, clinicians ruled out other causes of seizures and suspected that his episode was related to the ingestion. However, LSD does not typically cause seizures, and routine drug screening didnt provide any clues. Extended toxicology screening was requested, and using liquid chromatography-high resolution mass spectrometry (LC-HRMS), we identified dimethoxychloroamphetamine (DOC) in the patients urine and serum.1 DOC is a potent hallucinogen that is often mistaken for LSD, and at high doses, has been reported to cause seizures.
Dynamic Secondary Ion Mass Spectrometry. Essential Knowledge Briefing Dynamic Secondary Ion Mass Spectrometry Surface analysis is the cornerstone of a wide range of scientific disciplines, from
Press release - Clinical Mass Spectrometry Market Report 2018 - Clinical Mass Spectrometry Market Report 2018: Segmentation by Product (GAS Chromatography-Mass Spectrometry, Liquid Chromatography-Mass Spectrometry, MALDI TOF Mass Spectrometer, Capillary Electrophoresis-Mass Spectrometry, Ion Mobility Spectrometry-Mass - published on openPR.com
TY - JOUR. T1 - Quantitation of the anticancer drug abiraterone and its metabolite Δ(4)-abiraterone in human plasma using high-resolution mass spectrometry. AU - Bhatnagar, Atul. AU - McKay, Matthew J.. AU - Crumbaker, Megan. AU - Ahire, Ketan. AU - Karuso, Peter. AU - Gurney, Howard. AU - Molloy, Mark P.. PY - 2018/5/30. Y1 - 2018/5/30. N2 - Abiraterone acetate is administered as a prodrug to patients with metastatic, castration-resistant prostate cancer (mCRPC) and is readily metabolized into the potent 17a-hydroxylase/17,20-lyase (CYP17) enzyme inhibitor and androgen receptor inhibitor abiraterone and Δ(4)-abiraterone (D4A), respectively. To investigate pharmacokinetic variability in abiraterone acetate metabolism we developed highly sensitive liquid chromatography/mass spectrometry (LC/MS) assays for the simultaneous quantitation of abiraterone and D4A in human plasma using high-resolution mass spectrometry (HRMS) on an Orbitrap mass spectrometer. This study demonstrates the quantitative ...
TY - JOUR. T1 - Probing conformational changes of ubiquitin by host-guest chemistry using electrospray ionization mass spectrometry. AU - Lee, Jong Wha. AU - Heo, Sung Woo. AU - Lee, Shin Jung C.. AU - Ko, Jae Yoon. AU - Kim, Hyungjun. AU - Kim, Hugh I.. PY - 2013/1/1. Y1 - 2013/1/1. N2 - We report mechanistic studies of structural changes of ubiquitin (Ub) by host-guest chemistry with cucurbit[6]uril (CB[6]) using electrospray ionization mass spectrometry (ESI-MS) combined with circular dichroism spectroscopy and molecular dynamics (MD) simulation. CB[6] binds selectively to lysine (Lys) residues of proteins. Low energy collision-induced dissociation (CID) of the protein-CB[6] complex reveals CB[6] binding sites. We previously reported (Anal. Chem. 2011, 83, 7916-7923) shifts in major charge states along with Ub-CB[6] complexes in the ESI-MS spectrum with addition of CB[6] to Ub from water. We also reported that CB[6] is present only at Lys6 or Lys11 in high charge state (+13) complex. In this ...
Metal ions play significant roles in biological processes, and investigation of metal-protein interactions provides a basis to understand the functions of metal ions in such systems. In the current study, a novel matrix-assisted nanoelectrospray ionization mass spectrometry (MANESI-MS) method was developed for inve
TY - JOUR. T1 - An evaluation of the utility of in vacuo methylation for mass-spectrometry-based analyses of peptides. AU - Laremore, Tatiana Nikolaevna. AU - Weber, David M.. AU - Choma, Christin T.. PY - 2005/8/3. Y1 - 2005/8/3. N2 - In vacuo trimethylation of the N-terminus of a lyophilized peptide with methyl iodide was previously reported to enhance the peptides signal in matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and to suppress alkali adduct formation in electrospray ionization mass spectrometry (ESI-MS). Both the signal enhancement and alkali adduct suppression observed for methylated peptides are believed to be due to the permanent positive charge on the N-terminus of the peptide resulting from the formation of a quaternary ammonium moiety. The present work evaluates the general utility of the in vacuo methylation procedure for the MS analysis of peptides, and specifically addresses the issue of whether the methylation of nucleophilic sites other than the ...
TY - JOUR. T1 - Targeted peptide measurements in biology and medicine. T2 - Best practices for mass spectrometry-based assay development using a fit-for-purpose approach. AU - Carr, Steven A.. AU - Abbatiello, Susan E.. AU - Ackermann, Bradley L.. AU - Borchers, Christoph. AU - Domon, Bruno. AU - Deutsch, Eric W.. AU - Grant, Russell P.. AU - Hoofnagle, Andrew N.. AU - Hüttenhain, Ruth. AU - Koomen, John M.. AU - Liebler, Daniel C.. AU - Liu, Tao. AU - MacLean, Brendan. AU - Mani, D. R.. AU - Mansfield, Elizabeth. AU - Neubert, Hendrik. AU - Paulovich, Amanda G.. AU - Reiter, Lukas. AU - Vitek, Olga. AU - Aebersold, Ruedi. AU - Anderson, Leigh. AU - Bethem, Robert. AU - Blonder, Josip. AU - Boja, Emily. AU - Botelho, Julianne. AU - Boyne, Michael. AU - Bradshaw, Ralph A.. AU - Burlingame, Alma L.. AU - Chan, Daniel. AU - Keshishian, Hasmik. AU - Kuhn, Eric. AU - Kinsinger, Christopher. AU - Lee, Jerry S H. AU - Lee, Sang Won. AU - Moritz, Robert. AU - Oses-Prieto, Juan. AU - Rifai, Nader. AU - ...
The fast atom bombardment (FAB) mass spectra of bouvardin (1) 6-O-methylbouvardin (2), deoxybouvardin (3) and a synthetic analog (4) have been examined. The spectra of the bicyclic compounds 1-3 display site-directed fragmentations resulting from the presence of a phenolic bridged tyrosine moiety un …
Data Availability StatementThe mass spectrometry proteomics data have already been deposited towards the ProteomeXchange Consortium via the Satisfaction partner repository using the dataset identifier PXD002600 and 10. poorer inducing and result chemotherapy level of resistance in stable tumors. The unique trend of pseudo-hypoxia linked to mutation was seen in clear-cell, however, not in papillary RCC, and the treating this subtype of Wisp1 cancer is demanding continue to. Despite the intro of fresh antiangiogenic targeted treatments (tyrosine kinase inhibitors, TKIs), individuals develop both major and acquired level of resistance even now. Overcoming level of resistance to TKIs, in papillary RCC also, could be possible simply by finding modified protein expression considerably. To get this done, hypoxic 3D in vitro versions must be created to mimic both molecular pathways normal for low air pressure and cellCcell dynamics in tumor-like spatial constructions. Outcomes Clear-cell and papillary ...
TY - JOUR. T1 - A combination of molecular probe-tandem electrospray ionization mass spectrometry. T2 - A technique for tracing structural changes in phospholipid hydroperoxides. AU - Shimizu, Rumiko. AU - Nagai, Ai. AU - Tominaga, Hiroko. AU - Imura, Megumi. AU - Onyango, Arnold N.. AU - Izumi, Minoru. AU - Nakajima, Shuhei. AU - Tahara, Shoichi. AU - Kaneko, Takao. AU - Baba, Naomichi. PY - 2009. Y1 - 2009. N2 - An ethyl-labeled phosphatidylcholine hydroperoxide (PC-OOH/Et 2) was synthesized as a molecular probe for naturally occurring PC-OOH 1. Applying the precursor ion scan mode in tandem ESI mass spectrometry at m/z 198, a signal of the PC-OOH/Et 2 alone could be selectively detected even in the presence of a large excess of a complex mixture of phospholipids in the blood. Furthermore, molecular species that formed from PC-OOH/Et 2 by its degradation in the blood were also observed in the same spectrum. Since the molecular probe-and-mass spectrometry-assisted analytical method presented ...
Sports doping in both humans and animals is a widespread problem. Paper spray is a direct ionization technique that simplifies the mass spectrometric analysis of compounds from physiological fluids, making it an attractive method for clinical research and forensic toxicology applications. In this work, methamphetamine and other stimulant drugs were spiked in horse urine to demonstrate the potential of the technique to monitor sport doping in horse racing. Paper spray ionization presents chall
The ion trap mass spectrometer is a modified form of the quadrupole mass spectrometer, and was originally designed as a chromatography detector. However, the combination of the ion trap mass spectrometer with its capacity for mass analysis and the chromatograph is a useful tandem technique. The ion trap mass spectrometer has a quite different electrode configuration to the quadrupole mass spectrometer and consists of three cylindrically symmetrical electrodes comprised of two end caps and a ring. The device can be easily miniaturized, the opposite internal electrode faces being only 2 cm apart. Each electrode has hyperbolic internal faces and in a similar manner to the quadrupole spectrometer, an rf voltage together with an DC voltage is applied to the ring and the end caps are grounded. As with the quadrupole mass spectrometer, the rf voltage causes rapid reversals of field direction, so any ions are alternately accelerated and decelerated in the axial direction and vice versa in the radial ...