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Ambient ionization

Xiaoping Zhang, Konstantin Chingin, Dacai Zhong, Liping Luo, Vladimir Frankevich, Huanwen Chen
The chemical origin and biological role of distinct semen-like odor occasionally found in some flowers are very curious but remain scarcely studied. Here, we used direct ambient corona discharge ionization mass spectrometry (MS) to study the volatile chemical composition behind the semen-like odor emitted by the fresh flowers of Photinia serrulata, Castanopsis sclerophylla and Stemona japonica without any chemical pretreatment. Chemical identification was performed using high-resolution MS analysis in combination with tandem MS analysis and whenever possible was confirmed by the analysis of standard reference compounds...
November 8, 2017: Phytochemistry
Elizabeth A Crawford, Stefanie Gerbig, Bernhard Spengler, Dietrich A Volmer
Ambient ionization techniques are typically used to analyze samples in their native states with minimal or no sample pretreatment prior to mass spectrometric (MS) analysis. Desorption electrospray ionization (DESI) and direct analysis in real time (DART) were systematically investigated in this work for direct solid analysis of depolymerized lignin samples, with the goal of rapidly fingerprinting these samples, to efficiently characterize the subunits of this renewable energy source. High resolution MS was required for enhanced selectivity in this study due to the inherent structural complexity of lignin...
November 22, 2017: Analytica Chimica Acta
Daoiz Zamora, Mario Amo-Gonzalez, Marta Lanza, Gonzalo Fernandez De La Mora, Juan Fernandez de la Mora
The feasibility of detecting explosives in the atmosphere at concentrations as low as 0.01 ppq hinges on the poorly known question of what interfering species exist at these or higher concentrations. To clarify the issue, hundreds of samples of ambient air, either clean or loaded with explosives (from lightly contaminated environments) have been collected in fiberglass/stainless steel filters coated with Tenax-GR, thermally desorbed at variable temperature, and ionized with Cl- via secondary electrospray (SESI)...
November 9, 2017: Analytical Chemistry
Kang Li, Li Li, Bo Cui, Zhihui Gai, Qiuyue Li, Shumei Wang, Jun Yan, Bencheng Lin, Lei Tian, Huanliang Liu, Xiaohua Liu, Zhuge Xi
Epidemiological studies have revealed that ambient fine particulate matter (PM2.5) exposure is closely associated with autism spectrum disorder (ASD). However, there is a relative paucity of laboratory data to support this epidemic finding. In order to assess the relationship between PM2.5 exposure and ASD, neonatal male Sprague-Dawley (SD) rats were chosen and exposed to PM2.5 (2 or 20 mg/kg body weight, once a day) by intranasal instillation from postnatal day (PND) 8 to 22. It was found that when exposed to PM2...
November 7, 2017: Toxicological Sciences: An Official Journal of the Society of Toxicology
Jácint Jónás, János Somlai, Anita Csordás, Edit Tóth-Bodrogi, Tibor Kovács
In petroleum engineering, the produced drilling mud sometimes contains elevated amounts of natural radioactivity. In this study, a remediated Hungarian drilling mud depository was investigated from a radiological perspective. The depository was monitored before and after a clay layer was applied as covering. In this study, the ambient dose equivalent rate H*(10) of the depository has been measured by a Scintillator Probe (6150AD-b Dose Rate Meter). Outdoor radon concentration, radon concentration in soil gas, and in situ field radon exhalation measurements were carried out using a pulse-type ionization chamber (AlphaGUARD radon monitor)...
November 2, 2017: Journal of Environmental Radioactivity
Emily L Gill, Megan Marks, Richard A Yost, Vinata Vedam-Mai, Timothy Garrett
Liquid-microjunction surface sampling (LMJ-SS) is an ambient ionization technique based on the continuous flow of solvent using an in situ micro-extraction device, in which solvent moves through the probe, drawing in the analytes in preparation for ionization using an electrospray ionization (ESI) source. However, unlike traditional mass spectrometry (MS) techniques it operates under ambient pressure and requires no sample preparation, thereby making it ideal for rapid sampling of thicker tissue sections for electrophysiological and other neuroscientific research studies...
October 31, 2017: Analytical Chemistry
George Gachumi, Anas El-Aneed
Plant sterols (phytosterols) are important structural components of plant cellular membranes, and they play a major role during development and metabolism. They have health-associated benefits, especially in lowering blood cholesterol levels. Because of their many health claims, there is a growing interest in their analysis. Although various analytical strategies have been employed in analyzing phytosterols, chromatography linked to mass spectrometry (MS) is superior due to its sensitivity. Furthermore, specificity and selectivity are enhanced by utilizing tandem mass spectrometry (MS/MS)...
November 8, 2017: Journal of Agricultural and Food Chemistry
Yan Li, Longxing Wang, Xiuhua Zhu, Yuan Gao, Jiping Chen
A high performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS) method was developed for the determination of hexabromocyclododecanes (HBCDs) in ambient air samples. The samples were extracted by Soxhlet extractor with hexane, then purified on the composite gel column. At first, the interfering substances were rinsed with 50 mL hexane and 100 mL hexane-dichloromethane (9:1, v/v), then 180 mL hexane -dichloromethane (4:1, v/v) was used to elute the targets. The compounds were separated by gradient elution with acetonitrile-methanol-water as mobile phases on a UF-ODS column (150 mm×2...
October 8, 2017: Se Pu, Chinese Journal of Chromatography
Xianjiang Li, Wen Ma, Hongmei Li, Wanpeng Ai, Yu Bai, Huwei Liu
Ambient mass spectrometry provides great convenience for fast screening, and has showed promising potential in analytical chemistry. However, its relatively low sensitivity seriously restricts its practical utility in trace compound analysis. In this review, we summarize the sampling and analyte enrichment strategies coupled with nine modes of representative ambient mass spectrometry (desorption electrospray ionization, paper vhspray ionization, wooden-tip spray ionization, probe electrospray ionization, coated blade spray ionization, direct analysis in real time, desorption corona beam ionization, dielectric barrier discharge ionization, and atmospheric-pressure solids analysis probe) that have dramatically increased the detection sensitivity...
October 13, 2017: Analytical and Bioanalytical Chemistry
Jiaquan Xu, Shengrui Xu, Yipo Xiao, Konstantin Chingin, Haiyan Lu, Runhan Yan, Huanwen Chen
Rapid quantitative determination of bulk molecular concentration in solid samples without sample pretreatment is demonstrated using the internal extractive electrospray ionization-mass spectrometry (iEESI-MS) analysis of six β-agonists, including salbutamol (Sal), clenbuterol (Cle), ractopamine (Rac), terbutaline (Ter), tulobuterol (Tul), brombuterol (Bro), in pork tissue samples. Single sample analysis only required 1 min. The linear range of detection was about 0.01-1000 μg/kg (R(2) > 0.9994). The limit-of-detection (LOD) varied from 0...
November 7, 2017: Analytical Chemistry
Depanjan Sarkar, Anirban Som, Thalappil Pradeep
Materials are making inroads into mass spectrometry, and an example is the use of advanced materials for enhanced ionization by transformation of a less-ionizable molecule to an easily ionizable one. Here we show the use of Pt nanoparticle-decorated nanotubes as highly active catalysts for the reduction of 2,4,6-trinitrotoluene to 2,4,6-triaminotoluene and subsequent easy detection of the product by in situ ambient ionization mass spectrometry.
November 7, 2017: Analytical Chemistry
Valentina Pirro, Raquel Sero Llor, Alan K Jarmusch, Clint M Alfaro, Aaron A Cohen-Gadol, Eyas M Hattab, R Graham Cooks
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 identifying the disease state of tissue and in better characterizing the resection margin. To explore this potential, we studied 29 human brain tumor specimens and obtained evidence that this technique can provide diagnostic molecular information that is relevant to brain cancer. Touch spray using medical swabs involves the physical sampling of tissue using a medical swab on a spatial scale of a few mm(2) with subsequent ionization occurring directly from the swab tip upon addition of solvent and application of a high voltage...
October 23, 2017: Analyst
F Leontaris, A Clouvas, S Xanthos, A Maltezos, C Potiriadis, E Kiriakopoulos, J Guilhot
The Telemetric Early Warning System Network of the Greek Atomic Energy Commission consists mainly of a network of 24 Reuter-Stokes high-pressure ionization chambers (HPIC) for gamma dose rate measurements and covers all Greece. In the present work, the response of the Reuter-Stokes HPIC to terrestrial and cosmic radiation was evaluated in comparison with spectroscopic data obtained by in situ gamma spectrometry measurements with portable hyper pure Germanium detectors (HPGe), near the Reuter-Stokes detectors and time series analysis...
August 10, 2017: Radiation Protection Dosimetry
Seyed Mostafa Mohammadi, Hossein Tavakoli-Anbaran
The free-air ionization chamber is communicating with the ambient air, therefore, the atmospheric parameters such as temperature, pressure and humidity effect on the ionization chamber performance. The free-air ionization chamber, entitled as FAC-IR-300, that design at the Atomic Energy Organization of Iran, AEOI, is required the atmospheric correction factors for correct the chamber reading. In this article, the effect of humidity on the ionization chamber response was investigated. For this reason, was introduced the humidity correction factor, kh...
August 30, 2017: Radiation Protection Dosimetry
Jan Rejšek, Vladimír Vrkoslav, Vít Pokorný, Vladimír Přibyl, Josef Cvačka
The analysis of nonplanar samples in ambient mass spectrometry poses a formidable challenge. Here, an ion source equipped with laser triangulation for analyzing nonplanar surfaces was constructed. It was designed as a two-position device, where the sample height was measured using laser triangulation and the target compounds were then analyzed. Thanks to a stage movable in xyz, the ion source maintained an optimal vertical distance between the sample and the sampling capillary for each measured spot during the surface analysis...
November 7, 2017: Analytical Chemistry
Jillian A Jastrzembski, Madeleine Y Bee, Gavin L Sacks
Ambient ionization mass spectrometric (AI-MS) techniques like direct analysis in real time (DART) offer the potential for rapid quantitative analyses of trace volatiles in food matrices, but performance is generally limited by the lack of preconcentration and extraction steps. The sensitivity and selectivity of AI-MS approaches can be improved through solid-phase microextraction (SPME) with appropriate thin-film geometries, for example, solid-phase mesh-enhanced sorption from headspace (SPMESH). This work improves the SPMESH-DART-MS approach for use in food analyses and validates the approach for trace volatile analysis for two compounds in real samples (grape macerates)...
October 11, 2017: Journal of Agricultural and Food Chemistry
Mark Busman
Ambient ionization represents a new generation of MS ion sources and is used for the rapid ionization of smallmolecules under ambient conditions. The combination of ambient ionization and MS allows the analysis of multiple food samples with simple or no sample treatment or in conjunction with prevailing sample preparation methods. Two ambient ionization methods, desorptive electrospray ionization (DESI) and direct analysis in real time (DART) have been adapted for food safety application. Both ionization techniques provide unique advantages and capabilities...
October 2, 2017: Journal of AOAC International
Sho Matsuno, Masahiro Yamashina, Yoshihisa Sei, Munetaka Akita, Akiyoshi Kuzume, Kimihisa Yamamoto, Michito Yoshizawa
Structural determination of inorganic clusters relies heavily on mass spectrometry because of, in most cases, their poor responsivities toward nuclear magnetic resonance, ultraviolet/visible, and infrared analyses. Nevertheless, mass spectrometry analysis of oligosulfurs (S n ), which are unique clusters with copious allotropic forms, usually displays their fragment peaks. Here we report that a polyaromatic capsule acts as a supramolecular matrix for the mass determination of the neutral sulfur clusters. Upon encapsulation, molecular ion peaks derived from the host-guest complexes including cyclic S6 and S8 clusters are exclusively detected by common electrospray ionization time-of-flight mass spectrometry analysis...
September 29, 2017: Nature Communications
Akira Motoyama, Keishi Kihara
To provide safe and effective products to customers in the cosmetic industry, mass spectrometry (MS) is an indispensable analytical tool. In addition to its outstanding sensitivity and specificity, the method is applicable to a wide variety of compounds, which makes it irreplaceable for the development of cosmetics, which requires the analysis of complex systems. Because most cosmetic products are applied directly to the skin and function as they are designed, monitoring the molecular compositions of endogenous or exogenous compounds in or on the skin is crucial to ensure the safety and efficacy of a cosmetic product...
2017: Mass Spectrometry
Dana M Freund, Amanda C Martin, Jerry D Cohen, Adrian D Hegeman
Leaf spray-MS minimizes tissue manipulation by effectively and quickly assessing in vivo specialized metabolites from intact plant tissue surfaces, including trichome metabolites. Intact leaves of Glycyrrhiza lepidota Pursh. (American licorice) were analyzed by direct electrospray leaf spray-MS, an ambient ionization technique. Comparison of metabolites detected by leaf spray-MS to those from LC-MS of bulk tissue and trichome enriched extracts showed dramatic differences. Leaf spray-MS results suggest that in specific situations this approach could complement traditional LC-MS analysis of bulk extracts...
September 27, 2017: Planta
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