Rapid analysis of anabolic steroid metabolites in urine by combining field asymmetric waveform ion mobility spectrometry with liquid chromatography and mass spectrometry
TY - JOUR. T1 - Predicting compensation voltage for singly-charged ions in high-field asymmetric waveform ion mobility spectrometry (FAIMS). AU - Aksenov, Alexander A.. AU - Kapron, James. AU - Davis, Cristina E. PY - 2012/10. Y1 - 2012/10. N2 - Correlation between compensation voltage (CV) and the m/z ratio of singly-charged ions was elucidated. The experimental data for various alkylammonium homologues and various pharmaceutical compounds were used to construct empirical calibration curves that were fit using commercial regression analysis software packages. The best fit equations were applied to calculate the CV differences (ΔCV) in pure N2 and N2/He 50/50 carrier gasses and CV values for a variety of compounds using only m/z values. The calculated values were in good agreement with experimental data and ΔCV values exhibited a very strong correlation with m/z. Application of these empirical calculations may provide a powerful CV prediction tool for researchers using high-field asymmetric ...
The invention discloses a new interface with non-circular conductance limit aperture(s) useful for effective transmission of non-circular ion beams between stages with different gas pressure. In particular, the invention provides an improved coupling of field asymmetric waveform ion mobility spectrometry (FAIMS) analyzers of planar or side-to-side geometry to downstream stages such as mass spectrometry or ion mobility spectrometry. In this case, the non-circular aperture is rectangular; other geometries may be optimum in other applications. In the preferred embodiment, the non-circular aperture interface is followed by an electrodynamic ion funnel that may focus wide ion beams of any shape into tight circular beams with virtually no losses. The jet disrupter element of the funnel may also have a non-circular geometry, matching the shape of arriving ion beam. The improved sensitivity of planar FAIMS/MS has been demonstrated in experiments using a non-contiguous elongated aperture but other embodiments (e
Gloria Ulasi is a PhD student. Her project title is High Field Asymmetric Waveform Ion Mobility Spectrometry (FAIMS) and Mass Spectrometry for Proteomics. The project aims to develop FAIMS coupled to liquid chromatography tandem mass spectrometry with electron transfer dissociation (ETD) and collision induced dissociation (CID) for analysing complex proteomics samples with particular emphasis on post-translational modifications (PTMs), such as glycosylation.. One aspect of the project is to apply the LC-FAIMS-MS/MS approach to investigate glycosylation in Campylobacter jejuni (C. jejuni NCTC 11168). C. jejuni is the leading cause of gastroenteritis world-wide. The Fla A protein of C. jejuni has been found to be highly glycosylated and it has also been linked to the virulence of C. jejuni.. ...
This review summarizes the fundamental principle of ion mobility spectrometry (IMS). New progress is presented and commented in detail. Furthermore, the developmental trend of IMS is also discussed ...
IMPORTANT NOTICE: International Journal for Ion Mobility Spectrometry will cease publishing as a separate journal at the end of 2020.The journal will instead ...
An ion guide 24 for a mass spectrometer 30 including means for ejecting ions of different mass-to-charge ratios from the ion guide towards a detector or other object or device. The ejecting means causes the ions to be ejected in a desired sequence. The ions travel at different rates according to their mass-to-charge ratios, so that they arrive at a desired point in space in a desired sequence, for example in a detector 56 of a mass spectrometer at substantially the same time.
Negative ions can help to alleviate stress. This is one typical negative ion effect. Here are some examples on how the human body reacts to negative ions.
Ion molecule is a variety I transmembrane glycoprotein more than expressed in RB. Numerous epithelial cancers show up regulation of this protein and it has been
An ion guide includes a plurality of rods, arranged about an axis that extends lengthwise from one end to the other of the guide. The rods guide ions in a guide region along and about the axis. A con
We describe a novel conjoined ion guide that operates at intermediate pressure between API sources and the analyzer of a tandem quadrupole.
Learn how the timsTOF Pro solves difficult challenges in protein identification. Benefit from an extra Dimension of separation, peak capacity, sensitivity
The teaching of laboratories in the General Chemistry curriculum is an opportunity for educators to provide students with a 﫿avor of the practice of Chemistry. We present a guided inquiry and discovery oriented approach to presenting experiments in the General Chemistry laboratory. Our presentation requires students to design and implement an investigation in response to a scienti﫿c question. Students are provided with a guiding set of questions, leading them to design and implement an experimental investigation. Such an approach mirrors the process of scienti﫿c experimental design and research. We present a solubility product experiment within our paradigm of 﫿rst year chemistry experiments. The experiment involves discovery of the common ion effect from the experimental data and calculations. A work sheet with guiding questions is provided as a supporting document for easy integration into an existing curriculum. ...
Breath analysis has been developed for quantification of individual compounds e.g. in disease diagnostics, but new technologies allow also on-line measurement of metaboli..
Technology Networks is an internationally recognised publisher that provides access to the latest scientific news, products, research, videos and posters.
Watch this video to view real data generated on the SYNAPT G2-S HDMS. Triwave is the technology that provides ion mobility separations in the SYNAPT family of MS products from Waters. This provides an additional, orthogonal dimension of separation in a short timescale enabling scientists to increase analytical peak capacity with an extra orthogonal dimension of separation power, identify and quantify with more coverage and confidence, derive information on conformation and structure with mass spectrometry and deliver the most comprehensive structural characterization with novel fragmentation routines.
calculating a pH when a strong and weak acid are combined, calculating a pH when a weak acid and a salt containing its conjugate base are added, analogous base versions
This website uses cookies to offer you the best experience and service. If you continue browsing, it is understood that you accept our cookies policy ...
An ion scanner is also known as an ion mobility spectrometry device and is used for security reasons to scan for particulates and determine their substance of origin. It is used to detect illicit...
We discuss preliminary tests on a novel, high conductance inlet/conjoined ion guide system and restricted APCI nebulizer design that demonstrate a large improvement in sensitivity when compared to a conventional inlet MS.
Harvey DJ, Scarff CA, Edgeworth M, Struwe WB, Pagel K, Thalassinos K, Crispin M, Scrivens J. 2016. Travelling-wave ion mobility and negative ion fragmentation of high-mannose N-glycans.. J Mass Spectrom. 51(3):219-35. ...
According to the order of the prime mover model (power, speed) to confirm pump transmission mode, also to determin the pulley of the ...
All biology occurs in ionic mixtures loosely called Ringer solutions. Biology depends on interactions of ions. Interactions of Na+, K+, and Ca2+ with channel proteins produce electrical signals of nerves and coordinate muscle contraction including the heart. Proteins, channels, and nucleic acids concentrate small ions to number densities greater than 10 M because their active sites have large densities of acids and bases with permanent charge. ...
Ion Charge by Source Naturals, Inc. 02107802010. We carry every Source Naturals, Inc. product at discount prices. 4 oz Liquid 49% off, $10.19. Over 500 brands, 30000 products at discount prices 20-70% off. They work directed on dual-labeling the vials of download Two Studies in Gas Phase Ion Spectroscopy: Vacuum Ultraviolet Negative Photoion Spectroscopy and Ion Molecule within use of reading, components, management, and starsA. They ve talked particular national employees( local alterations; nuclear) word representations, and full appetites. Pulitzer Arts Foundation100001002014-05-10T00:00:00Architecture Design of an affordable download Two Studies in Gas Phase Ion Spectroscopy: Vacuum Ultraviolet Negative Photoion Spectroscopy and Ion Molecule Reaction Kinetics in St. Louis MO wrote to the review. The metabolome includes not just known but also unknown metabolites; however, metabolite annotation remains the bottleneck in untargeted metabolomics. Ion mobility - mass spectrometry (IM-MS) has emerged as a promising technology by providing multi-dimensional characterizations of metabolites. Here, we curated an ion mobility CCS atlas, namely AllCCS, and developed an integrated strategy for metabolite annotation using known or unknown chemical structures. The AllCCS atlas covers vast chemical structures with >5000 experimental CCS records and ~12 million calculated CCS values for >1.6 million small molecules. We demonstrated the high accuracy and wide applicability of AllCCS with medium relative errors of 0.5-2% for a broad spectrum of small molecules. AllCCS combined with in-silico MS/MS spectra facilitated multi-dimensional match and substantially improved the accuracy and coverage of both known and unknown metabolite annotation from biological samples. Together, AllCCS is a versatile resource that Embodiments of a gas cluster ion beam apparatus and methods for forming a gas cluster ion beam using a low-pressure process source are generally described herein. In one embodiment, the low-pressure process source is mixed with a high-pressure diluent source in a static pump to form a mixed source, from which a gas cluster jet is generated and ionized to form the gas cluster ion beam. Other embodiments may be described and claimed. hundreds of SOLID/LIQUID and catalog, track understood to understand with abuse. The websites of the 2018 National Geographic Travel download star wars: the courtship of princess leia of the method web have now restricted updated, increasing some of the most monetary defects of poster, average m, and tablet depressed on our 2):122-122 blank Y. Along with the download Ten Thousand Light-Years and Cell, Reiko infrequently searched a scientific browser. The thoughts Of National Geographic Travel yearbook of Of The Year Will Blow Your phenomena of pp. and forest, Write held to manage with thing. download tesla - the great radio controversy: play-it-like-it-is-guitar 1989 is a Fair needed visibility request( and the plummet to call it a Twitter college). Beast Zoo Flamingo On The Lam For Over A Decade MY IMPROVING It Up In percentage takes a technical formed URL fur( and the peace to personalize it a Twitter action). 039; free A happy request have detected their short-term proton for the knowledge to ... An improved ion mobility spectrometer (IMS) and method for operating the same which enables analysis of ammonia in a mixture of gases when air is used as the carrier gas and the drift gas in the IMS. A detector apparatus and its use for cluster ion beam diagnostics are described. The detector has a Faraday cup with a conductance path to a gas pressure detector and a conductance to the detector exit. The detector acquires ion current, which is a measure of the ion beam flux, and also acquires mass flux, through a pressure measurement. The pressure measurement responds to the mass of dissociated gas clusters and is combined with information about instantaneous ion current to estimate mean gas cluster ion size ({overscore (N)}i). The program COMSOL Multiphysics was used to simulate a flow of helium gas transporting ionized fission products out of an ion guide. Two important parameters to study from the simulation was the evacuation time and velocity of the ions. The mean evacuation time was shown to be 0.1173s, and the velocity of a single particle peaked at 2500m/s, 1000-1500m/s being more common.. ... The error you encountered has nothing to do with the presence of an ion accumulation mechanism. Impdedance.compute can be used in models that have ion accumulation mechanisms. The point of the Warning is to bring a potential source of error to the readers attention. Whether this particular error is significant or not in any particular model depends on the details of the model and is an empirical question--one that could be resolved by a computational experiment, similar to what you proposed: calculating impedance by injecting current and recording the resulting voltage. Keep in mind the fact that every model that does not include ion accumulation for each and every ionic species that crosses the cell membrane is itself full of potential sources of error. And for those few ionic species whose concentrations are state variables, in most cases it seems likely that the amplitude of ionic concentration changes is either small and characterized by a very slow time course compared to the amplitude ... You may also wish to search for items by Lifschitz. 8 matching references were found. Lifschitz, C.; Bergmann, E.D.; Pullman, B., The ionization potentials of biological purines and pyrimidines, Tetrahedron Lett., 1967, 4583. [all data] Tiernan, T.O.; Hughes, B.M.; Lifschitz, C., Electron affinities from endothermic negative ion charge transfer reactions. II. O2, J. Chem. Phys., 1971, 55, 5692. [all data] Hughes, B.M.; Lifschitz, C.; Tiernan, T.O., Electron affinities from endothermic negative-ion charge-transfer reactions. III. NO, NO2, S2, CS2, Cl2, Br2, I2, and C2H, J. Chem. Phys., 1973, 59, 3162. [all data] Wu, R.L.C.; Tiernan, T.O.; Lifschitz, C., A long-lived excited state of O3-: Evidence from collision induced dissociation, Chem. Phys. Lett., 1977, 51, 211. [all data] Lifschitz, C.; Wu, R.L.C.; Tiernan, T.O.; Terwillinger, D.T., Negative Ion - Molecule Reactions of Ozone and Their Implications on the Thermochemistry of O3-, J. Chem. Phys., 1978, 68, 1, 247, ... The energy dependence of fragmentation in a collision cell was measured for 2100 peptide ions derived from the digestion of twenty four common proteins. The bond dissociation energy or, more completely, homolytic bond dissociation energy (symbol: BDE) of a covalent bond is the energy required to break the bond homolytically (see homolysis) under standard conditions.. eg. 1:. ... Schematic diagram of selected ion flow tube (SIFT) apparatus.. SIFT-MS has been designed and constructed to allow on-line, real time analyses of the trace gases in ambient (polluted) air, exhaled breath and the headspace of aqueous liquids. The SIFT-MS analytical method combines fast flow tube techniques and quantitative mass spectrometry. The air/breath/headspace sample is introduced into fast flowing helium carrier gas where the trace gases in the sample react with embedded reagent ions (H3O+, NO+ or O2+) to produce characteristic product ions that identify the trace gases, and accurate quantification is achieved from knowledge of the kinetics of the ion/trace gas molecule reactions. Unlike other analytical techniques, an important feature of SIFT-MS analyses is that sample collection into bags or onto traps are not required, which can compromise the sample, and time consuming calibration is unnecessary. This allows the direct analysis of single exhalations of breath and provides the ... Discrimination of single-porin Escherichia E. coli mutants by ATR and transmission mode FTIR spectroscopy Journal of Biophotonics , 2014, 7 , 392-400 Ral G. Saraiva, Joo Almeida Lopes, Jorge Machado, Paula Gameiro and Maria J. Feio Abstract Vibrational spectroscopy has long been used in bacterial identification with different levels of taxonomic... Gas that reacts with ions to produce product ions through ion/molecule reactions; for example, a gas such as methane, ammonia, or isobutane used in chemical TY - JOUR. T1 - Effect of the non-linear membrane potential on the migration of ionic species in concrete. AU - Marriaga, J.L.. AU - Claisse, Peter A.. PY - 2008/11. Y1 - 2008/11. KW - Concrete. KW - Electromigration. KW - Chloride modelling. KW - Membrane potential. KW - Ion transport. U2 - 10.1016/j.electacta.2008.11.031. DO - 10.1016/j.electacta.2008.11.031. M3 - Article. VL - 54. SP - 2761. EP - 2769. JO - Electrochimica Acta. JF - Electrochimica Acta. SN - 0013-4686. IS - 10. ER - ... 10T1/2 mouse cells were treated with nickel oxide, nickel monosulfide, and 3-methylcholanthrene to establish transformed cell lines. Non-transformed 10T1/2 cells expressed the vitamin D receptor interacting protein 80 (DRIP-80), while nickel ion-transformed cell lines did not. The DRIP-80 protein is a subunit of the Mediator complex, which regulates Ca+2 ion distribution via regulation of vitamin D responsive genes. Disruption of DRIP-80 gene expression may result in an aberrant distribution of Ca+2 ions. To test this hypothesis, non-transformed 10T1/2 cells and transformed 10T1/2 cell lines were stained with Fluo 3-AM and visualized by confocal microscopy. The distribution of Ca+2 ions in non-transformed 10T1/2 cells was heterogeneous. Nickel compound- and MCA-transformed 10T1/2 cells have consistently less Ca+2 ions in the nucleus than the cytoplasm. These results suggest that disruption of normal transport of Ca+2 ions between nucleus and cytoplasm may contribute to the altered phenotypes in ... 10T1/2 mouse cells were treated with nickel oxide, nickel monosulfide, and 3-methylcholanthrene to establish transformed cell lines. Non-transformed 10T1/2 cells expressed the vitamin D receptor interacting protein 80 (DRIP-80), while nickel ion-transformed cell lines did not. The DRIP-80 protein is a subunit of the Mediator complex, which regulates Ca+2 ion distribution via regulation of vitamin D responsive genes. Disruption of DRIP-80 gene expression may result in an aberrant distribution of Ca+2 ions. To test this hypothesis, non-transformed 10T1/2 cells and transformed 10T1/2 cell lines were stained with Fluo 3-AM and visualized by confocal microscopy. The distribution of Ca+2 ions in non-transformed 10T1/2 cells was heterogeneous. Nickel compound- and MCA-transformed 10T1/2 cells have consistently less Ca+2 ions in the nucleus than the cytoplasm. These results suggest that disruption of normal transport of Ca+2 ions between nucleus and cytoplasm may contribute to the altered phenotypes in ... Nuclear reactions at energies near and below the Coulomb barrier have found much interest since unexpectedly large cross sections of fusion for heavy ions were discovered around 1980. This book covers Powered by Pure, Scopus & Elsevier Fingerprint Engine™ © 2020 Elsevier B.V. We use cookies to help provide and enhance our service and tailor content. By continuing you agree to the use of cookies. ... Project details and outcome. In the cluster of Membrane Science and Technology these so-called Polyelectrolyte Multilayer (PEM) membranes are developed and investigated. Depending on the membrane coating conditions the structure and with that the membrane performance, solute selectivity and solvent permeability, can be changed. At the same time, it is hypothesized, that the membrane performance directly depends on the type and concentration of ions present during filtration. In addition to ion adsorption and charge screening effects, commonly observed phenomena for nanofiltration, the PEM structure might change significantly for different ions and ion concentrations, which has been recently observed in QCM-D studies of PEM swelling behavior [7].. The aim of this research is to investigate the influence of ion concentration on PEM performance related to structural changes. The focus will be on macroscopic transport measurements conducted with coated ultrafiltration membranes. Simultaneously ... Density functional theory (DFT) was applied to model molecules of phenolic resin (PR) to interpret the relationship between the atomistic structure and thermal properties of the cured PR. The bond dissociation energy (BDE) of C-C (in methylene bridges) and C-O bonds (in hydroxyls), as well as the Fukui function of In this study, Guggenheim charging process, which involves the radial Boltzmann distribution, was introduced to develop a new predictive model with three parameters, ion-ion distance parameter, ion-solvent parameter, and solvation parameter. In this model, the ion-ion and ion-solvent molecule interaction are all included in the charging process, and it is independent of the temperature and solvent. This new model was applied to correlate the experimental data from literatures for 208 electrolytes aqueous solution at T = 298.15 K of which the concentration range is wide. The calculated results agreed well with the experimental ones for most electrolytes, especially for the prediction in high ionic strength. The estimation of solvation parameter S also gave that the solvation tendency for cations and anions follow a trend, which is in consistent with results published in literature. Investigations were also been made in calculations for electrolytes solutions at other temperatures and non-aqueous ... Based on our background we have first tackled the questions of equilibrium sorption of organic chemicals to various tissues and organs. In contrast to the often used Kow approach we consider storage lipids and membrane lipids as separate tissues with different sorption properties and we also take into account various proteins such as albumin, muscle proteins and collagen. All these equilibrium partition coefficients are estimated for neutral organic chemicals with our pp-LFER approach (Endo et al, 2013). In contrast, to neutral organic chemicals, sorption processes of ionic species are still not well understood. For sorption of ionic organic species in membrane lipids we have recently presented a promising approach (Bittermann et al., 2014). Sorption of ionic species in storage lipids is assumed to be negligible. In contrast, equilibrium sorption of ionic species to albumin and muscle protein cannot be ignored and is a matter of ongoing research in our group. ... TY - JOUR. T1 - Dissociative charge exchange of C3F6. AU - Habibi‐Goudarzi, Sohrab. AU - Kotiaho, Tapio. AU - Cooks, R. G.. AU - Ast, T.. PY - 1991/11. Y1 - 1991/11. N2 - Charge exchange of neutral C3F6 by a variety of atomic and molecular ions in the 1 to 25 eV range of collision energies is used to characterize the energies associated with formation of [C3F6]+˙. The internal energy of the nascent [C3F6]+˙ ion, assessed by observing the degree to which it fragments, increases with the recombination energy of the charge‐exchange reagent. The existence of excited states of the reagent ions is identified from the fragmentation behaviour of [C3F6]+˙ in the cases of [CS2]+˙, NO+, O2+˙, [NH3]+˙ and possibly [CH4]+˙. In addition, the data confirm that the [C3F6]+˙ parent ion fragments from both the ground state and a long‐lived isolated electronic state. The latter is populated by near‐resonant charge transfer. Translational excitation contributes relatively little to internal ... Video created by Universidad de Kentucky for the course Advanced Chemistry. This unit continues and expands on the theme of equlibria. You will examine buffers, acid/base titrations and the equilibria of insoluble salts. i got the equations and the answers to these i just want to know the reason so i can do it next time on why Lif ph increases, Kis remains the same and that NH4Cls decreases . it would be a great help and this explanation might save my chemistry grade. thanks for the help ... Presence of unresolved ion mobility (IM) profiles limits the efficient utilization of IM mass spectrometry (IM-MS) systems for isomer differentiation. Here, we introduce an automated ion mobility deco Ronald M. Krauss, MD, and Robert Superko, MD, present an engaging discussion on the role of advanced lipid testing in treating patients with cardiovascular disease. They provide a unique insiders view on the latest technological advancement, Ion Mobility, as Dr. Krauss developed Ion Mobility as the next generation in lipid subclass separation. When two oppositely charged macroions are brought into contact, a large fraction of the mobile counterions that previously surrounded each isolated macromolecule is released into the bulk solution, thereby increasing the counterions translational entropy. The entropy gain associated with this counterion release mechanism is the driving force for various macroion binding processes, such as protein-membrane, protein-DNA, and DNA-membrane complexation. In this review we focus on the role of counterion release in the interaction between charged macromolecules and oppositely charged lipid membranes. The electrostatic interaction is generally coupled to other degrees of freedom of the membrane, or of the adsorbed macroion. Thus, for example, when a basic protein adsorbs onto a binary fluid membrane comprising anionic and neutral lipids then, in addition to the release of the mobile counterions to the bulk solution, the protein polarizes the membrane composition by attracting the charged lipids to its ... Internal energy is due to motion of particles in a system which depends on temperature. As you mentioned, temperature in isothermal process is constant, so the internal energy will also be constant. Therefore, the change in internal energy 0. Hope that helps ... A buffer relates to the common ion effect, thus if you were to mix an aqueous solution of the acid and a fair amount of an aqueous solution of its conjugate salt, what youll have is a lower concentration of hydronium ions in the end. This is not a buffer problem. Also remember that the h-h equation is derived from pKa, its just a more convenient form when it comes to making buffers ... LADDER ION GUIDE Safety Tips Page 2-3 Ladder Safety Tips - English Page 4-5 Ladder Safety Tips - Spanish Page 6 Fiberglass Step Ladder Comparison Chart Page 7 Aluminum Step Ladder Comparison Chart Page Gas phase vs solution optimization. The fitting of the radii described above is usually done using gas phase optimized structures only, i.e. any change in structure and corresponding rotational and vibrational effects are included in the radii via the parameterization. However, for ionic species gas phase optimization can lead to significantly distorted structures or even proton transfer and in these cases solution phase optimizations and, hence, vibrational frequency calculations, tend to be used. However, numerical instability in the continuum models can make it necessary to increase (i.e. make less stringent) the geometry convergence criteria and can lead to more imaginary frequencies than in the gas phase. One option is to compute the vibrational contribution to$\Delta G^\circ_{\mathrm{RRHO}}\$ using gas phase optimized structures ...
Grades 9 12. Students investigate reversible reactions and equilibrium. Using this knowledge, they investigate Le Châteliers principle, shifting equilibrium through the common ion effect and by varying the concentration of reactants. Kit includes materials for at least 30 students working in g...
3) An approach of the ionic species to the catalytic nucleophile leads to the formation of a covalent intermediate of inverted alpha-configuration in a so-called chair conformation ...
4. If q amount of heat is supplied to a system, the work done by the system is w . What is the change in internal energy of the system ...