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Search results for: DESORPTION ELECTROSPRAY IONIZATION–MASS SPECTROMETRY
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Determination of PCBs in marine sediment using pressurised liquid extraction-gas chromatography-isotope dilution mass spectrometry -method validation
PublicationOpracowano procedurę oznaczania wybranych analitów z grupy PCB w próbkach osadu dennego z wykorzystaniem techniki przyspieszonej ekstrakcji za pomocą rozpuszczalnika (PLE) w połączeniu z chromatografią gazową z detektorem spektrometrii mas. Opracowana procedura analityczna została wykorzystana do analizy próbek morskiego osadu dennego, które stanowiły przedmiot badań międzylaboratoryjnych organizowanych przez Comité Consultatif...
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Comparison of classical and modern approach of determination of highly polar compounds by High Performance Liquid Chromatography coupled with Tandem Mass Spectrometry
PublicationAbstract: Sugars and sugar alcohols are known as highly polar compounds. Four analytes were taken into consideration for comparison of classical and modern approach of separation of highly polar substances. Mannitol was chosen as an example of simple sugar alcohol, sucrose and lactulose as examples of disaccharides and structural isomers, raffinose as an example of complex trisaccharide. Raffinose was also used as internal standard...
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Sensitive simultaneous determination of 19 fluorobenzoic acids in saline waters by solid-phase extraction and liquid chromatography–tandem mass spectrometry
PublicationA solid-phase extraction (SPE) procedure using C18 stationary phase was optimized for the preconcentration of 19 fluorinated derivatives of benzoic acid (FBA): mono-, di-, tri-, and tetrafluorosubstituted in the ring, trifluoromethylbenzoic acid and 3,5-bistrifluoromethyl benzoic acid from undiluted salt-rich (>20%) reservoir waters. Quantitative (>90%) retention/elution of 16 out of 19 analyte compounds was achieved allowing a...
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Analysis of chiral pharmaceutical residues in influent and effluent samples at racemic and enantiomeric level using liquid chromatography-tandem mass spectrometry
PublicationIn this work, two different chromatographic methods for seasonal monitoring of pharmaceutical residue in wastewater samples were developed. In the case of enantiomeric separation of selected compounds, LC-MS technique combining with vancomycin based chiral stationary phase was used. The performance of chiral analysis enabled to monitor the pharmaceutical contamination at the enantiomeric level. The d-SPE procedure was developed...
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Discrepancies in determination of biogenic amines in beer samples by reversed phase and hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry
PublicationBiogenic amines (BAs) are nitrogenous organic bases occurring mainly in fermented food and beverages as a result of free amino acids bacterial decarboxylation. The reversed phase liquid chromatography (RPLC) and hydrophilic interaction liquid chromatography (HILIC) based methods were compared in terms of usefulness for determination of BAs in beer samples. Analysis of BAs with the use of RPLC method were carried out after their...
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Complementary Use of Multi-dimensional Gas Chromatography and Proton Transfer Reaction Mass Spectrometry for Identification of Rapeseed Oil Quality Indicators
PublicationThe change of concentration of various volatiles generated during frying may be an indicator of oil quality. Chemical compounds such as aldehydes, ketones, alcohols and carboxyl acids are the products of oxidation during thermal degradation of edible oils. Shown in this work is a complementary use of GC×GC-TOFMS and PTR-MS for the detection and determination of quality indicators of rapeseed oil. The former technique was used for...
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Determination of trace levels of eleven bisphenol A analogues in human blood serum by high performance liquid chromatography–tandem mass spectrometry
PublicationChemicals showing structural or functional similarity to bisphenol A (BPA), commonly called BPA analogues, have recently drawn scientific attention due to their common industrial and commercial application as a substitute for BPA. In the European Union, the use of BPA has been severely restricted by law due to its endocrine disrupting properties. Unfortunately, it seems that all BPA analogues show comparable biological activity,...
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Comprehensive determination of flavouring additives and nicotine in e-cigarette refill solutions. Part II: Gas-chromatography–mass spectrometry analysis
PublicationFlavouring compounds are an essential part of e-liquid products for cigarettes. In general, they are regarded as safe for ingestion, but they may have unrecognized risks when they are inhaled. In some cases, manufactures do not currently abide by the Tobacco Products Directive (2014/40/EU) and do not declare the detailed contents of e-liquids on their labels. To help evaluate the health impact of flavouring substances, there is...
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Determination of robenidine in animal feeds by liquid chromatography coupled with diode-array detection and mass spectrometry after accelerated solvent extraction
PublicationRobenidyna (chlorowodorek 1,3-bis[(4-chlorobenzylideno)amino]guanidyny) jest stosowana w celu zapobiegania i leczenia kokcydiozy - pasożytniczej choroby układu pokarmowego wielu zwierząt hodowlanych (kozy, owce, króliki, drób) wywoływanej przez pierwotniaki należące do rzędu Eimeria tenella, E. Necatrix, E. Acervulina, E. Maxima, E. Brunetti, and E. Mivati. Robenidyna wykazuje stosunkowo wysoką skuteczność terapeutyczną, przy niewielkiej...
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Fast, sensitive and reliable multi-residue method for routine determination of 34 pesticides from various chemical groups in water samples by using dispersive liquid – liquid microextraction coupled with gas chromatography – mass spectrometry
PublicationA simple and efficient dispersive liquid-liquid microextraction technique (DLLME) was developed by using a mixture of two solvents: 40 μL of tetrachlorethylene (extraction solvent) and 1.0 mL of methanol (disperser solvent), which was rapidly injected with a syringe into 10mL ofwater sample. Some important parameters affecting the extraction efficiency, such as type and volume of solvents, water sample volume, extraction time,...
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Electron impact iozization of CCl4 and SF6 embedded in superfluid helium droplets
PublicationElectron impact ionization of helium nano-droplets containing several 104 He atoms and doped with CCl4 or SF6 molecules is studied with high-mass resolution. The mass spectra show significant clustering of CCl4 molecules, less so for SF6 under our experimental conditions. Positive ion efficiency curves as a function of electron energy indicate complete immersion of the molecules inside the helium droplets in both cases. For CCl4...
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Recent advancements in LC‐MS based analysis of biotoxins: Present and future challenges
PublicationThere has been a rising concern regarding the harmful impact of biotoxins, source of origin, and the determination of the specific type of toxin. With numerous reports on their extensive spread, biotoxins pose a critical challenge to figure out their parent groups, metabolites, and concentration. In that aspect, liquid chromatography‐mass spectrometry (LC‐MS) based analysis paves the way for its accurate identification and quantification....
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Comparison of peptide cancer signatures identified by mass spectrometry in serum of patients with head and neck, lung and colorectal cancers: Association with tumor progression
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Variations of odorous VOCs detected by different assessors via gas chromatography coupled with mass spectrometry and olfactory detection port (ODP) system
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Quantification of unconjugated and total ibuprofen and its metabolites in equine urine samples by gas chromatography–tandem mass spectrometry: Application to the excretion study
PublicationIbuprofen (IBU) is a widely used nonsteroidal anti-inflammatory drug (NSAID) in human and also veterinary medicine. NSAIDs are usually highly metabolized compounds in horses; they are often present in equine urine, mostly in their conjugated forms (glucuronides). Thus, hydrolysis to cleave the glucuronide linkage prior to anti-doping analysis is often necessary for improving detection. In this study, unconjugated and total IBU...
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Development of a solventless stir bar sorptive extraction/thermal desorption large volume injection capillary gas chromatographic-mass spectrometric method for ultra-trace determination of pyrethroids pesticides in river and tap water samples
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Detection of molecular signatures of oral squamous cell carcinoma and normal epithelium - application of a novel methodology for unsupervised segmentation of imaging mass spectrometry data
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Potential of Serum Proteome Patterns Analysis by MALDI-TOF Mass Spectrometry for Prediction of Acute Radiation Injury Response in Head and Neck Cancers Patients
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Application of gas chromatography-mass spectrometry preceded by solvent extraction to determine volatile fatty acids in wastewater of municipal, animal farm and ladfill origin
PublicationW ramach przeprowadzonych badań została opracowana metodyka oznaczania lotnych kwasów tłuszczowych (LKT) z próbek ścieków pochodzących z oczyszczalni ścieków komunalnych, farm zwierząt oraz ze składowiska odpadów organicznych, techniką ekstrakcji ciecz-ciecz (LLE) za pomocą eteru metylo-tert-butylowego (MTBE) jako ekstahenta. Dobrano optymalne warunki chromatograficznego rozdzielania i oznaczania LKT w próbkach środowiskowych,...
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Monitoring the BTEX Volatiles during 3D Printing with Acrylonitrile Butadiene Styrene (ABS) Using Electronic Nose and Proton Transfer Reaction Mass Spectrometry
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Simultaneous determination of hydrophobicity and dissociation constant for a large set of compounds by gradient reverse phase high performance liquid chromatography–mass spectrometry technique
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Application of headspace-solid phase microextraction followed by gas chromatography-mass spectrometry to determine short-chain alkane monocarboxylic acids in aqueous samples
PublicationCelem prowadzonych badań było opracowanie metodyki oznaczania krótkołańcuchowych kwasów alkanomonokarboksylowych (KKA), opartej na ich izolowaniu i wzbogacaniu za pomocą techniki HS-SPME, a następnie oznaczaniu za pomocą chromatografii gazowej sprzężonej ze spektrometrią mas (GC-MS). Do ekstrakcji zastosowano włókno pokryte polarną fazą stacjonarną opartą na glikolu polietylenowym (PEG). Dla celów porównawczych zastosowano również...
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Monitoring the BTEX Volatiles during 3D Printing with Acrylonitrile Butadiene Styrene (ABS) Using Electronic Nose and Proton Transfer Reaction Mass Spectrometry
PublicationWe describe a concept study in which the changes of concentration of benzene, toluene, ethylbenzene, and xylene (BTEX) compounds and styrene within a 3D printer enclosure during printing with different acrylonitrile butadiene styrene (ABS) filaments were monitored in real-time using a proton transfer reaction mass spectrometer and an electronic nose. The quantitative data on the concentration of the BTEX compounds, in particular...
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A new silylating reagent – dimethyl(3,3,3-trifluoropropyl)silyldiethylamine – for the derivatisation of non-steroidal anti-inflammatory drugs prior to gas chromatography–mass spectrometry analysis
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Determination of bromhexine and its metabolites in equine serum samples by liquid chromatography – Tandem mass spectrometry: Applicability to the elimination study after single oral dose
PublicationBromhexine (BH), expectorant used in the treatment of respiratory disorders associated with viscid or excessive mucus, is not permitted for use in the competing horse by many authorities in horseracing and Olympic disciplines. Metabolic studies are of the great importance in anti-doping field because they allow for updating the selection of the most appropriate markers for prohibited substances, such as metabolites present at higher...
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Dispersive solid-phase extraction using multi-walled carbon nanotubes combined with liquid chromatography–mass spectrometry for the analysis of β-blockers: Experimental and theoretical studies
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Determination of parent and methylated polycyclic aromatic hydrocarbons in water samples by dispersive liquid–liquid microextraction–two dimensional gas chromatography–time-of-flight mass spectrometry
PublicationPolycyclic aromatic hydrocarbons (PAHs) are contaminants frequently found in environmental waters. Owing to their toxic effects, it is important to develop analytical methodologies that allow their fast and reliable determination. Dispersive liquid–liquid microextraction (DLLME) allows a quick extraction of analytes with little organic solvent consumption. The best results regarding sample preparation are obtained when 40 mL of...
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Determination of tributyltin (TBT) in marine sediment using pressurised liquid extraction–gas chromatography–isotope dilution mass spectrometry (PLE–GC–IDMS) with a hexane–tropolone mixture
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Determination of tributylotin (TBT) in marine sediment using pressurised liquid extraction-gas chromatography-isotope dilution mass spectrometry (PLE-GC-IDMS) with a hexane-tropolone mixture
PublicationOpracowano metodę oznaczania zawartości tributylocyny w próbkach osadu morskiego. Na etapie izolacji zastosowano technikę przyspieszonej ekstrakcji za pomocą roztworu tropolonu w heksanie.Na etapie oznaczeń końcowych wykorzystano technikę chromatografii gazowej, stosując metodę spektrometrii mas rozcieńczenia izotopowego. Wyznaczono parametry walidacyjne opracowanej metody: granicę wykrywalności, precyzję, poprawność i niepewność.
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Application of headspace-solid phase microextraction followed by gas chromatography-mass spectrometry to determine short-chain monocarboxylic acids in cattle farm wastewater and waste landfill leachates
PublicationZaproponowano metodykę oznaczania krótkołańcuchowych kwasów monokarboksylowych w ściekach z hodowli bydła i odciekach ze składowisk zawierających organiczne odpady, oparta na technice mikroekstrakcji do fazy stacjonarnej z fazy nadpowierzchniowej próbek ciekłych, w połączeniu ze sprzężonym układem GC-MS.
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Simultaneous analysis of non-steroidal anti-inflammatory drugs and estrogenic hormones in water and wastewater samples using gas chromatography–mass spectrometry and gas chromatography with electron capture detection
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Application of gas flow headspace liquid phase micro extraction coupled with gas chromatography-mass spectrometry for determination of 4-methylimidazole in food samples employing experimental design optimization
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Ionization and ionic fragmentation of tetrahydrofuran molecules by electron collisions
PublicationElectron impact ionization and ionic fragmentation of tetrahydrofuran molecules in the gas phase were studied in the energy range from ionization threshold up to 150 eV using the technique of mass spectrometry. The cation mass spectra, ionization and ionic fragmentation efficiencies were measured over this energy range. Well-resolved mass peaks were detected in the mass range 10-72 amu and assigned to corresponding ionic molecular...
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Association between plasma proteome profiles analysed by mass spectrometry, a lymphocyte-based DNA-break repair assay and radiotherapy-induced acute mucosal reaction in head and neck cancer patients
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Application of gas chromatography,mass spectrometry and olfactometry for quality assessment of selected food products = Zastosowanie chromatografii gazowej, spektrometrii mas i olfaktometrii w ocenie jakości wybranych produktów spożywczych
PublicationStosując mikroekstrakcję do fazy stacjonarnej z fazy nadpowierzchniowej jako metodę przygotowania próbek i chromatografię gazową (GC) ze spektrometrią mas (MS) i olfaktometrią (O) jako metodę oznaczeń końcowych oznaczono lotne związki w spirytusach i miodach. Identyfikację przeprowadzono przez porównanie widm masowych z widmami z biblioteki NIST. Dodatkowo, wykrywane przez panel oceniający związki zapachowe rejestrowano w formie...
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Accurate, Direct, and High-Throughput Analyses of a Broad Spectrum of Endogenously Generated DNA Base Modifications with Isotope-Dilution Two-Dimensional Ultraperformance Liquid Chromatography with Tandem Mass Spectrometry: Possible Clinical Implication
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Dehydrogenation in electron-induced dissociative ionization of pyridine molecule
PublicationThe electron-impact dissociative ionization of pyridine has been investigated using mass spectrometry. Thirty-two well-resolved mass peaks have been identified in the cation mass spectra and assigned to the most likely ionic molecular fragments. The new sixteen ionic fragments' appearance energies have been determined, and sixteen others remeasured. The total cross-section for electron-impact ionization of pyridine has been measured...
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Electron-impact ionization cross section of formic acid
PublicationExperimental electron-impact ionization cross sections of one of the simplest carboxylic acids, formic acid, are presented. The molecular target was studied in two independent experimental setups applying different methods: the total ion collection and the electron–impact mass spectrometry methods. Experimental data were taken at incident electron energies ranging from ionization threshold [11.31 eV; J.C. Traeger, Int. J. Mass...
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Monitoring of volatile organic compounds (VOCs) in atmospheric air. Part I. On-line gas analyzers
PublicationThe paper reviews the subject literature concerning the analytical instruments routinely used for monitoring volatile organic compounds in atmospheric air. The analyzers are classified as stationary or mobile according to their ease of transport. Stationary DOAS (Differential Optical Absorption Spectroscopy) analyzer is characterized, as are MIMS (Membrane Introduction Mass Spectrometry), MESI (Membrane Extraction with Sorbent...
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Unveiling the electron-induced ionization cross sections and fragmentation mechanisms of 3,4-dihydro-2H-pyran
PublicationThe interactions of electrons with molecular systems under various conditions are essential to interdisciplinary research fields extending over the fundamental and applied sciences. In particular, investigating electron-induced ionization and dissociation of molecules may shed light on the radiation damage to living cells, the physicochemical processes in interstellar environments, and reaction mechanisms occurring in combustion...
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A fast and convenient method for analysis of collagen hydrolysis products Szybka i dogodna metoda analizy produktów hydrolizy kolagenu
PublicationPolypeptides produced by hydrolysis of collagen from minced animal hide and skin scraps were studied by mass spectrometry (MS) in conjunction with electrophoresis to det. their mol. mass. The degree of peptides ionisation was ca 50+. This allowed for observation of the large polypeptide chains with mass analyzers with a relatively low m/z range. The electrospray and atm. pressure photoionization techniques were used. The polypeptide...
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Dissociative ionization dynamics of dielectric gas C3F7CN
PublicationFluoronitrile C3F7CN is a promising candidate for the replacement of SF6 dielectric gas in high-voltage insulation. We present a combined experimental and theoretical study on its ionization dynamics probed in the 0-100 eV energy range. We exploited the total ion collection technique to determine the absolute ionization cross section, mass spectrometry to determine the fragment branching ratios and ab initio nonadiabatic molecular...
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Application of Headspace Solid-phase Microextraction with Poly(1-vinyl-3- Hexylimidazolium Chloride) Polymeric Ionic Liquid Coating using GC - MS to Determine Volatile Fatty Acids in Dairy Wastewater
PublicationVolatile fatty acids were determined in this study using headspace solid-phase microextraction (HS-SPME) with a poly(1-vinyl-3-hexylimidazolium chloride) polymeric ionic liquid coated fiber followed by gas chromatography - mass spectrometry. Experimental parameters such as extraction time and temperature, sample volume as well as desorption time and temperature were optimized. Detection limits of the method were in the range of...
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Storing Matter’technique in SIMS depth profile analysis
PublicationSecondary ion mass spectrometry (SIMS) is a very useful technique for the analysis of layered systems. It is based on the primary ion beam sputtering of solids and mass analysis of the emitted secondary ions. A main limitation of this technique results from the direct quantitative analysis, since the ionization efficiency of a given atom is highly influenced by the neighbouring atoms at the surface. This phenomenon is known as...
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The difficulties in polybrominated diphenyl ethers identification by GC-EI-MS technique
PublicationAwareness about the harmful effects of brominated flame retardants on living organisms increases mainly due to link their presence in the human environment with health disorders. Therefore is a need to conduct research aimed at content control of these chemicals in the environment. Recent improvements in injection techniques and mass spectrometer ionization methods have led to a variety of options to determine PBDEs in environmental...
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Electron impact ionization and cationic fragmentation of the pyridazine molecules
PublicationElectron impact mass spectroscopy was used to investigate ionization and cationic fragmentation of the pyridazine (1,2 diazine), C4H4N2, molecules in the gas phase. The mass spectra were measured and the observed mass peaks assigned to the corresponding cations. The appearance energies of most of the cationic fragments were determined and the possible fragmentation processes are discussed. The total cross section for electron...
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Cross sections for ionization and ionic fragmentation of pyrimidine molecules by electron collisions
PublicationThe electron impact mass spectroscopy and the total ion collection measurements were used to investigate the ionization and ionic fragmentation of the pyrimidine, C4H4N2, molecules in the gasphase. The cation mass spectra were measured in the 10−85 amu range and the observed mass peaks assigned to corresponding ionic fragments. The most abundant cation in the mass spectra is the parent cation, C4H4N+2, at 80 amu. The appearance...
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The dispersive micro-solid phase extraction method for MS-based lipidomics of human breast milk*
PublicationA simple and rapid microextraction method ensuring high lipidome coverage was developed for liquid chromatography mass spectrometry (LC-MS)-based lipidomics of human breast milk. The dispersive microsolid phase extraction (D-µ-SPE) technique, coupled with the design of experiment (DoE) method, enabled the study of the influence of several conditions (desorption solvent, stationary phase ratio, and sorption and desorption time)...
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Dopants and gas modifiers in ion mobility spectrometry
PublicationThe ion mobility techniques, including the most commonly used drift-tube ion mobility spectrometry (IMS) and differential mobility spectrometry (DMS), are used successfully for the detection of a wide range of organic compounds in the gas phase. In order to improve detection quality, admixtures are added to gas streams flowing through the detector. Dopants mostly prevent the ionization of interfering chemicals however, better detection...
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Ionization and fragmentation of furan molecules by electron collisions
PublicationCation mass spectra obtained by electron impact were measured to investigate the ionization and ionic fragmentation of furan, C4H4O, molecules in the gas phase. The most abundant cations, with comparable intensities in the mass spectra, were the parent, C4H4O+, cation (68 amu) and the C3H3+ fragment (39 amu). The appearance energies of most of the observed ionic fragments were determined and the possible fragmentation processes...