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Ambient ionization

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https://www.readbyqxmd.com/read/28443843/atmospheric-pressure-soft-ionization-for-gas-chromatography-with-dielectric-barrier-discharge-ionization-mass-spectrometry-gc-dbdi-ms
#1
Mario F Mirabelli, Jan-Christoph Wolf, Renato Zenobi
In this study, a gas chromatography (GC) system was interfaced to a high-resolution Orbitrap mass spectrometer by means of an active capillary plasma ionization source, based on dielectric barrier discharge ionization (DBDI). This allowed highly efficient soft ionization of gas-phase, chromatographically resolved compounds at ambient pressure. Several pesticides and illicit drugs were analyzed, and the limits of detections (LODs) were as low as 30 pg mL(-1) for the GC-DBDI-MS coupling (corresponding to 60 fg on-column sensitivity) and 30 fg mL(-1) for SPME-GC-DBDI-MS...
April 26, 2017: Analyst
https://www.readbyqxmd.com/read/28443842/pulsed-valve-matrix-assisted-ionization
#2
Bijay Banstola, Kermit K Murray
We have developed a new ionization approach for matrix-assisted ionization with high temporal resolution using an electrically actuated pulsed valve. Matrix and analyte samples are deposited on a thin metal foil and placed at the inlet of an ambient ionization mass spectrometer. When the pulsed valve is actuated, a short puff of high pressure gas impinges on the foil and ejects particulate from the sample on the opposite side. Highly charged ions are formed from the particles at the mass spectrometer inlet...
April 26, 2017: Analyst
https://www.readbyqxmd.com/read/28420232/gas-phase-carboxylic-acids-in-a-university-classroom-abundance-variability-and-sources
#3
Shang Liu, Samantha L Thompson, Harald Stark, Paul J Ziemann, Jose L Jimenez
Gas-phase carboxylic acids are ubiquitous in ambient air, yet their indoor occurrence and abundance are poorly characterized. To fill this gap, we measured gas-phase carboxylic acids in real-time inside and outside of a university classroom using a high-resolution time-of-flight chemical ionization mass spectrometer (HRToF-CIMS) equipped with an acetate ion source. A wide variety of carboxylic acids were identified indoors and outdoors, including monoacids, diacids, hydroxy acids, carbonyl acids, and aromatic acids...
April 18, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28416487/metabolic-markers-and-statistical-prediction-of-serous-ovarian-cancer-aggressiveness-by-ambient-ionization-mass-spectrometry-imaging
#4
Marta Sans, Kshipra M Gharpure, Robert Tibshirani, Jialing Zhang, Li Liang, Jinsong Liu, Jonathan H Young, Robert Dood, Anil K Sood, Livia Eberlin
Ovarian high-grade serous carcinoma (HGSC) results in the highest mortality among gynecological cancers, developing rapidly and aggressively. Dissimilarly, serous borderline ovarian tumors (BOT) can progress into low-grade serous carcinomas and have relatively indolent clinical behavior. The underlying biological differences between HGSC and BOT call for accurate diagnostic methodologies and tailored treatment options, and identification of molecular markers of aggressiveness could provide valuable biochemical insights and improve disease management...
April 17, 2017: Cancer Research
https://www.readbyqxmd.com/read/28401996/exploration-and-performance-evaluation-of-microwave-induced-plasma-with-different-discharge-gases-for-ambient-desorption-ionization-mass-spectrometry
#5
Jingwei Yin, Zhongjun Zhao, Xuefang Zhan, Yixiang Duan
RATIONALE: Microwave-induced plasma (MIP) with different discharge gases of argon or helium provides significant plasma-based ambient desorption/ionization sources, which have potential applicability in direct analysis of complex samples without any sample pre-treatment. In this study, experiments were conducted to better understand microwave-induced plasma desorption/ionization (MIPDI) sources and the corresponding ionization mechanisms. METHODS: Emission spectra of microwave-induced argon (MIP-Ar) and helium (MIP-He) plasmas were obtained from the plasma tail flame of a MIP source...
April 12, 2017: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28395774/determination-of-elemental-composition-of-metals-using-ambient-organic-mass-spectrometry
#6
Christopher Shiea, Yeou-Lih Huang, Sy-Chyi Cheng, Yi-Lun Chen, Jentaie Shiea
Conventional inorganic mass spectrometric (MS) analysis of metals can require time-consuming and tedious sample preparation. We thus report the novel and direct characterization of metals in solid samples using an organic MS technique known as electrospray laser desorption ionization mass spectrometry (ELDI/MS). No sample pretreatment was needed, and results were rapidly obtained due to the ambient and laser-based nature of ELDI/MS. Metals from samples were desorbed and ionized by laser irradiation, after which they reacted with EDTA and then post-ionized and detected as metal-EDTA complexes...
May 22, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28394446/laser-ablation-electrospray-ionization-mass-spectrometry-with-ion-mobility-separation-reveals-metabolites-in-the-symbiotic-interactions-of-soybean-roots-and-rhizobia
#7
Sylwia A Stopka, Beverly J Agtuca, David W Koppenaal, Ljiljana Paša-Tolić, Gary Stacey, Akos Vertes, Christopher R Anderton
Technologies enabling in situ metabolic profiling of living plant systems are invaluable for understanding physiological processes and could be used for rapid phenotypic screening (e.g., to produce plants with superior biological nitrogen fixing ability). The symbiotic interaction between legumes and nitrogen-fixing soil bacteria results in a specialized plant organ (i.e., root nodule) where the exchange of nutrients between host and endosymbiont occurs. Laser ablation electrospray ionization mass spectrometry (LAESI-MS) is a method that can be performed under ambient conditions requiring minimal sample preparation...
April 10, 2017: Plant Journal: for Cell and Molecular Biology
https://www.readbyqxmd.com/read/28392779/complementary-metaproteomic-approaches-to-assess-the-bacterioplankton-response-toward-a-phytoplankton-spring-bloom-in-the-southern-north-sea
#8
Lars Wöhlbrand, Bernd Wemheuer, Christoph Feenders, Hanna S Ruppersberg, Christina Hinrichs, Bernd Blasius, Rolf Daniel, Ralf Rabus
Annually recurring phytoplankton spring blooms are characteristic of temperate coastal shelf seas. During these blooms, environmental conditions, including nutrient availability, differ considerably from non-bloom conditions, affecting the entire ecosystem including the bacterioplankton. Accordingly, the emerging ecological niches during bloom transition are occupied by different bacterial populations, with Roseobacter RCA cluster and SAR92 clade members exhibiting high metabolic activity during bloom events...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28364225/comparison-of-ambient-and-atmospheric-pressure-ion-sources-for-cystic-fibrosis-exhaled-breath-condensate-ion-mobility-mass-spectrometry-metabolomics
#9
Xiaoling Zang, José J Pérez, Christina M Jones, María Eugenia Monge, Nael A McCarty, Arlene A Stecenko, Facundo M Fernández
Cystic fibrosis (CF) is an autosomal recessive disorder caused by mutations in the gene that encodes the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The vast majority of the mortality is due to progressive lung disease. Targeted and untargeted CF breath metabolomics investigations via exhaled breath condensate (EBC) analyses have the potential to expose metabolic alterations associated with CF pathology and aid in assessing the effectiveness of CF therapies. Here, transmission-mode direct analysis in real time traveling wave ion mobility spectrometry time-of-flight mass spectrometry (TM-DART-TWIMS-TOF MS) was tested as a high-throughput alternative to conventional direct infusion (DI) electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) methods, and a critical comparison of the three ionization methods was conducted...
March 31, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28351629/detection-of-sub-pptv-benzene-toluene-and-ethylbenzene-via-low-pressure-photoionization-mass-spectrometry
#10
Zhen Li, Ce Xu, Jinian Shu
This paper reports on the advanced development of an ultrasensitive method for the detection of benzene, toluene, and ethylbenzene (or BTE) by low-pressure photoionization mass spectrometry (LPPI-MS). The LPPI source is composed of a laboratory-assembled krypton lamp and a stainless steel cylindrical ionizer. A compact V-shaped mass spectrometer is coupled to the LPPI source with a set of ion immigration optics under dc bias. The fixed standard concentration (FSC) and fixed standard volume (FSV) method are employed to calibrate the sensitivities of the instrument...
April 29, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28340788/rapid-identification-and-desorption-mechanisms-of-nitrogen-based-explosives-by-ambient-micro-fabricated-glow-discharge-plasma-desorption-ionization-mfgdp-mass-spectrometry
#11
CaiYan Tian, JinWei Yin, ZhongJun Zhao, Yinchenxi Zhang, YiXiang Duan
A novel technique of micro-fabricated glow discharge plasma desorption/ionization mass spectrometry was investigated for the first time in negative ion mode in this study. Negative ion micro-fabricated glow discharge plasma desorption/ionization mass spectrometry (NI-MFGDP-MS) was successfully applied to identify trace explosives in open air. Six explosives and explosives-related compounds were directly analyzed in seconds with this ion source. The ions of [M-H](-) were predominant for 2-methyl-1,3,5-trinitrobenzene (trinitrotoluene, TNT) and 2,4,6-trinitrophenol (picric acid), and [M+NO3](-) were dominant ions for 1,3,5-trinitro-perhydro-1,3,5-triazine (cyclonite, RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (octogen, HMX), 1,2,3-trinitroxypropane (nitroglycerin, NG), and pentaerythritol tetranitrate (PETN)...
May 15, 2017: Talanta
https://www.readbyqxmd.com/read/28337399/clinical-application-of-ambient-ionization-mass-spectrometry
#12
Li-Hua Li, Hua-Yi Hsieh, Cheng-Chih Hsu
Ambient ionization allows mass spectrometry analysis directly on the sample surface under atmospheric pressure with almost zero sample pretreatment. Since the development of desorption electrospray ionization (DESI) in 2004, many other ambient ionization techniques were developed. Due to their simplicity and low operation cost, rapid and on-site clinical mass spectrometry analysis becomes real. In this review, we will highlight some of the most widely used ambient ionization mass spectrometry approaches and their applications in clinical study...
2017: Mass Spectrometry
https://www.readbyqxmd.com/read/28329723/analysis-of-synthetic-phenethylamine-street-drugs-using-direct-sample-analysis-coupled-to-accurate-mass-time-of-flight-mass-spectrometry
#13
Maura K McGonigal, Joshua A Wilhide, Philip B Smith, Noelle M Elliott, Frank L Dorman
Serious health complications and fatal overdoses have brought phenethylamine, otherwise known as 2C, drug abuse to the public's attention. These compounds are 2C-X series analogs of mescaline. The name "2C" results from the two carbons in the ethyl chain. The substituents on these emerging drugs are constantly changed in order to avoid listing as controlled substances. These synthetic drugs are marketed as having affects similar to LSD and MDMA and are typically consumed sublingually via blotter paper. Twenty-six commercially available standards were analyzed using a direct sample analysis technique coupled to accurate mass time of flight mass spectrometry...
March 8, 2017: Forensic Science International
https://www.readbyqxmd.com/read/28328038/superbasic-alkyl-substituted-bisphosphazene-proton-sponges-a-new-class-of-deprotonating-matrices-for-negative-ion-matrix-assisted-ionization-laser-desorption-mass-spectrometry-of-low-molecular-weight-hardly-ionizable-analytes
#14
C D Calvano, T R I Cataldi, J F Kögel, A Monopoli, F Palmisano, J Sundermeyer
RATIONALE: Here hardly ionizable and low molecular weight compounds are detected in negative ion mode by using novel superbasic proton sponges based on 1,8-bisphosphazenylnaphthalene (PN) as MALDI matrices. Among the selected proton sponges, 1,8-bis(trispyrrolidinophosphazenyl)naphthalene (TPPN) has shown the best behaviour as matrix since it allows the direct detection of intact cholesterol without derivatization also in real challenging samples. METHODS: Very weakly acidic compounds such as sterols, steroids, fatty alcohols and saccharides were detected in reflectron negative ion mode by a MALDI TOF/TOF system equipped with a neodymium-doped yttrium lithium fluoride (Nd:YLF) laser (345 nm) with typical mass accuracy of 10 ppm...
July 30, 2016: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28321502/molecularly-imprinted-polymers-as-selective-adsorbents-for-ambient-plasma-mass-spectrometry
#15
Michał Cegłowski, Marek Smoluch, Edward Reszke, Jerzy Silberring, Grzegorz Schroeder
The application of molecularly imprinted polymers (MIPs) as molecular scavengers for ambient plasma ionization mass spectrometry has been reported for the first time. MIPs were synthesized using methacrylic acid as functional monomer; nicotine, propyphenazone, or methylparaben as templates; ethylene glycol dimethacrylate as a cross-linker; and 2,2'-azobisisobutyronitrile as polymerization initiator. To perform ambient plasma ionization experiments, a setup consisting of the heated crucible, a flowing atmospheric-pressure afterglow (FAPA) plasma ion source, and a quadrupole ion trap mass spectrometer has been used...
March 20, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28319370/uptake-and-disposition-of-select-pharmaceuticals-by-bluegill-exposed-at-constant-concentrations-in-a-flow-through-aquatic-exposure-system
#16
Jian-Liang Zhao, Edward T Furlong, Heiko L Schoenfuss, Dana W Kolpin, Kyle L Bird, David J Feifarek, Eric A Schwab, Guang-Guo Ying
The increasing use of pharmaceuticals has led to their subsequent input into and release from wastewater treatment plants, with corresponding discharge into surface waters that may subsequently exert adverse effects upon aquatic organisms. Although the distribution of pharmaceuticals in surface water has been extensively studied, the details of uptake, internal distribution, and kinetic processing of pharmaceuticals in exposed fish have received less attention. For this research, we investigated the uptake, disposition, and toxicokinetics of five pharmaceuticals (diclofenac, methocarbamol, rosuvastatin, sulfamethoxazole, and temazepam) in bluegill sunfish (Lepomis macrochirus) exposed to environmentally relevant concentrations (1000-4000 ng L(-1)) in a flow-through exposure system...
March 29, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28318234/light-absorbing-brown-carbon-aerosol-constituents-from-combustion-of-indonesian-peat-and-biomass
#17
Sri Hapsari Budisulistiorini, Matthieu Riva, Michael Williams, Jing Chen, Masayuki Itoh, Jason D Surratt, Mikinori Kuwata
Light-absorbing brown carbon (BrC) constituents of organic aerosol (OA) have been shown to significantly absorb ultraviolet (UV) and visible light and thus impact radiative forcing. However, molecular identification of the BrC constituents is still limited. In this study, we characterize BrC constituents at the molecular level in (i) aerosols emitted by combustion of peat, fern/leaf, and charcoal from Indonesia and (ii) ambient aerosols collected in Singapore during the 2015 haze episode. Aerosols were analyzed using ultra performance liquid chromatography instrument interfaced to a diode array detector and electrospray ionization high-resolution quadrupole time-of-flight mass spectrometer operated in the negative ion mode...
March 30, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28286302/recent-advances-in-the-detection-of-specific-natural-organic-compounds-as-carriers-for-radionuclides-in-soil-and-water-environments-with-examples-of-radioiodine-and-plutonium
#18
REVIEW
P H Santschi, C Xu, S Zhang, K A Schwehr, P Lin, C M Yeager, D I Kaplan
Among the key environmental factors influencing the fate and transport of radionuclides in the environment is natural organic matter (NOM). While this has been known for decades, there still remains great uncertainty in predicting NOM-radionuclide interactions because of lack of understanding of radionuclide interactions with the specific organic moieties within NOM. Furthermore, radionuclide-NOM studies conducted using modelled organic compounds or elevated radionuclide concentrations provide compromised information related to true environmental conditions...
May 2017: Journal of Environmental Radioactivity
https://www.readbyqxmd.com/read/28274593/in-depth-compositional-analysis-of-water-soluble-and-insoluble-organic-substances-in-fine-pm2-5-airborne-particles-using-ultra-high-resolution-15t-ft-icr-ms-and-gc%C3%A3-gc-tofms
#19
Jung Hoon Choi, Jijeong Ryu, Sodam Jeon, Jungju Seo, Yung-Hun Yang, Seung Pil Pack, Sungwook Choung, Kyoung-Soon Jang
Airborne particulate matter consisting of ionic species, salts, heavy metals and carbonaceous material is one of the most serious environmental pollutants owing to its impacts on the environment and human health. Although elemental and organic carbon compounds are known to be major components of aerosols, information on the elemental composition of particulate matter remains limited because of the broad range of compounds involved and the limits of analytical instruments. In this study, we investigated water-soluble and -insoluble organic compounds in fine (PM2...
March 5, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28271681/the-evaluation-of-colorectal-cancer-risk-in-serum-by-anti-desmin-conjugated-cdte-cds-quantum-dots
#20
Yao Wang, Yuanting Li, Zhiyong Chen, Tianhao Wang, Jie Gu, Xianhua Wu, Yi Yin, Maosheng Wang, Zhigang Pan
BACKGROUND: DESMIN is a novel prognostic predictor and therapeutic target for colorectal cancer (CRC). Enzyme-linked immunosorbent assay (ELISA) and electrochemiluminescence (ELC) assays are large-scale and highcost projects; therefore, it is necessary to develop a new, fast, and simple yet highly sensitive and specific method to detect DESMIN in serum. Semiconducting quantum dots (QDs) possess high fluorescence quantum yield, stability against photobleaching, and size-controlled luminescence properties, thus being utilized in photoelectrochemical tumor marker detection, especially in ameliorating the diagnostic value in complex biological ambient ionization...
March 1, 2017: Clinical Laboratory
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