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Ambient ionization

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https://www.readbyqxmd.com/read/28746793/easi-ims-an-expedite-and-secure-technique-to-screen-for-25i-nboh-in-blotter-papers
#1
Damila Rodrigues de Morais, Ingrid Lopes Barbosa, Kelly Francisco Cunha, Guilherme Lucas Tripodi, Célio Fernando Figueiredo Angolini, Marcos Fernando Franco, Elvis Medeiros de Aquino, Marcos Nogueira Eberlin, Jose Luiz Costa
The increasing number of new psychoactive substances (NPS) and their quick worldwide spreading, often only slightly modified in the form of new derivatives and analogues, have brought the need for fast, wide-ranging and unequivocal identification methods in clinical and forensic investigations. Since it usually provides secure results, gas chromatography coupled to mass spectrometry (GC-MS) has been routinely employed as the standard technique for the detection of NPS in blotter papers. For 25I-NBOH (N-(2-hydroxybenzyl)-2-(4-iodo-2,5-dimethoxyphenyl)ethan-1-aminium), however, GC-MS analysis of an blotter paper extract leads to incorrect results...
July 26, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28726382/interparticle-reactions-an-emerging-direction-in-nanomaterials-chemistry
#2
K R Krishnadas, Ananya Baksi, Atanu Ghosh, Ganapati Natarajan, Anirban Som, Thalappil Pradeep
Nanoparticles exhibit a rich variety in terms of structure, composition, and properties. However, reactions between them remain largely unexplored. In this Account, we discuss an emerging aspect of nanomaterials chemistry, namely, interparticle reactions in solution phase, similar to reactions between molecules, involving atomically precise noble metal clusters. A brief historical account of the developments, starting from the bare, gas phase clusters, which led to the synthesis of atomically precise monolayer protected clusters in solution, is presented first...
July 20, 2017: Accounts of Chemical Research
https://www.readbyqxmd.com/read/28718844/solvent-gradient-electrospray-for-laser-ablation-electrospray-ionization-mass-spectrometry
#3
Hang Li, Akos Vertes
Most electrospray based ambient ionization techniques, e.g., laser ablation electrospray ionization (LAESI), utilize a fixed spray solution composition. Complex samples often contain compounds of different polarity that exhibit a wide range of solubilities in the electrospray solvent. Thus, the fixed spray solution composition limits the molecular coverage of these approaches. Two-barrel theta glass capillaries have been used for the rapid mixing of two solutions for manipulating fast reactions including protein folding, unfolding, and charge state distributions...
July 18, 2017: Analyst
https://www.readbyqxmd.com/read/28692290/top-down-atmospheric-ionization-mass-spectrometry-microscopy-combined-with-proteogenomics
#4
Cheng-Chih Hsu, Michael W Baker, Terry Gaasterland, Michael J Meehan, Eduardo R Macagno, Pieter C Dorrestein
Mass spectrometry-based protein analysis has become an important methodology for proteogenomic mapping by providing evidence for the existence of proteins predicted at the genomic level. However, screening and identification of proteins directly on tissue samples, where histological information is preserved, remain challenging. Here we demonstrate that the ambient ionization source, nanospray desorption electrospray ionization (nanoDESI), interfaced with light microscopy allows for protein profiling directly on animal tissues at the microscopic scale...
July 24, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28681982/application-of-paper-spray-ionization-for-explosives-analysis
#5
Chia-Wei Tsai, Christopher A Tipple, Richard A Yost
RATIONALE: A desired feature in the analysis of explosives is to decrease the time of the entire analysis procedure, including sampling. A recently utilized ambient ionization technique, paper spray ionization (PSI), provides the possibility of combining sampling and ionization. However, an interesting phenomenon that occurs in generating negatively charged ions pose some challenges in applying PSI to explosives analysis. The goal of this work is to investigate the possible solutions for generating explosives ions in negative mode PSI...
July 6, 2017: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28667680/fast-and-comprehensive-characterization-of-chemical-ingredients-in-traditional-chinese-herbal-medicines-by-extractive-atmospheric-pressure-photoionization-eappi-mass-spectrometry
#6
Chengyuan Liu, Wu Wen, Jun Shao, Wan Zhao, Keke Qi, Jiuzhong Yang, Yang Pan
RATIONALE: The goal of this work is to employ extractive atmospheric pressure photoionization mass spectrometry (EAPPI MS) to characterize the constituents in traditional Chinese herbal medicine (TCHM) directly without chromatographic separation. METHODS: Sample was placed in 4 mL of methanol/water (v:v=3:1) in the nebulization cell, and then the ultrasonic nebulizer was switched on. Ultrasonic nebulization system allows the simultaneous sample extraction and introduction of extract aerosols...
July 1, 2017: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28656257/world-health-organization-radiofrequency-radiation-and-health-a-hard-nut-to-crack-review
#7
Lennart Hardell
In May 2011 the International Agency for Research on Cancer (IARC) evaluated cancer risks from radiofrequency (RF) radiation. Human epidemiological studies gave evidence of increased risk for glioma and acoustic neuroma. RF radiation was classified as Group 2B, a possible human carcinogen. Further epidemiological, animal and mechanistic studies have strengthened the association. In spite of this, in most countries little or nothing has been done to reduce exposure and educate people on health hazards from RF radiation...
June 21, 2017: International Journal of Oncology
https://www.readbyqxmd.com/read/28646605/observations-and-impacts-of-bleach-washing-on-indoor-chlorine-chemistry
#8
J P S Wong, N Carslaw, R Zhao, S Zhou, J P D Abbatt
Ambient levels of chlorinated gases and aerosol components were measured by on-line chemical ionization and aerosol mass spectrometers after an indoor floor was repeatedly washed with a commercial bleach solution. Gaseous chlorine (Cl2 , 10's of ppbv) and hypochlorous acid (HOCl, 100's of ppbv) arise after floor washing, along with nitryl chloride (ClNO2 ), dichlorine monoxide (Cl2 O) and chloramines (NHCl2 , NCl3 ). Much higher mixing ratios would prevail in a room with lower and more commonly encountered air exchange rates than that observed in the study (12...
June 24, 2017: Indoor Air
https://www.readbyqxmd.com/read/28640577/laser-ablation-molecular-isotopic-spectrometry-for-molecules-formation-chemistry-in-femtosecond-laser-ablated-plasmas
#9
Huaming Hou, Xianglei Mao, Vassilia Zorba, Richard E Russo
Recently, laser ablated molecular isotopic spectrometry (LAMIS) has expanded its capability to explore molecules formation mechanism in laser-induced plasma in addition to isotope analysis. LAMIS is a powerful tool for tracking the origination of atoms that is involved in formation of investigated molecules by labeling atoms with their isotopic substitution. The evolutionary formation pathways of organic molecules, especially of C2 dimers and CN radicals, were frequently reported. However, very little is known about the formation pathways for metallic radicals and heterodimers in laser ablated plasma...
July 7, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28636372/surface-desorption-dielectric-barrier-discharge-ionization-mass-spectrometry
#10
Hong Zhang, Jie Jiang, Na Li, Ming Li, Yingying Wang, Jing He, Hong You
A variant of dielectric-barrier discharge named surface desorption dielectric-barrier discharge ionization (SDDBDI) mass spectrometry was developed for high-efficiency ion transmission and high spatial resolution imaging. In SDDBDI, a tungsten nanotip and the inlet of the mass spectrometer are used as electrodes, and a piece of coverslip is used as a sample plate as well as an insulating dielectric barrier, which simplifies the configuration of instrument and thus the operation. Different from volume dielectric-barrier discharge (VDBD), the microdischarges are generated on the surface at SDDBDI, and therefore the plasma density is extremely high...
June 30, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28632988/solid-sampling-with-a-diode-laser-for-portable-ambient-mass-spectrometry
#11
Yeni P Yung, Raveendra Wickramasinghe, Anu Vaikkinen, Tiina J Kauppila, Igor V Veryovkin, Luke Hanley
A hand-held diode laser is implemented for solid sampling in portable ambient mass spectrometry (MS). Specifically, a pseudocontinuous wave battery-powered surgical laser diode is employed for portable laser diode thermal desorption (LDTD) at 940 nm and compared with nanosecond pulsed laser ablation at 2940 nm. Postionization is achieved in both cases using atmospheric pressure photoionization (APPI). The laser ablation atmospheric pressure photoionization (LAAPPI) and LDTD-APPI mass spectra of sage leaves (Salvia officinalis) using a field-deployable quadrupole ion trap MS display many similar ion peaks, as do the mass spectra of membrane grown biofilms of Pseudomonas aeruginosa...
July 18, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28631113/fast-determination-of-ingredients-in-solid-pharmaceuticals-by-microwave-enhanced-in-source-decay-of-microwave-plasma-torch-mass-spectrometry
#12
Rui Su, Xinchen Wang, Changming Hou, Meiling Yang, Keke Huang, Huanwen Chen
Rapid qualitative and quantitative analysis of solid samples (e.g., pharmaceutical preparations) by using a small and low-resolution mass spectrometer without MS/MS function is still a challenge in ambient pressure ionization mass spectrometric analysis. Herein, a practically efficient method termed microwave-enhanced in-source decay (MEISD) using microwave plasma torch desorption ionization coupled with time-of-flight mass spectrometry (MPTDI-TOF MS) was developed for fast analysis of pharmaceutical tablets using a miniature TOF mass spectrometer without tandem mass function...
June 19, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28628730/comparative-study-on-ambient-ionization-methods-for-direct-analysis-of-navel-orange-tissues-by-mass-spectrometry
#13
H Zhang, A Bibi, H Lu, J Han, H Chen
It is of sustainable interest to improve the sensitivity and selectivity of the ionization process, especially for direct analysis of complex samples without matrix separation. Herein, four ambient ionization methods including desorption atmospheric pressure chemical ionization (DAPCI), heat-assisted desorption atmospheric pressure chemical ionization (heat-assisted DAPCI), microwave plasma torch (MPT), and internal extractive electrospray ionization (iEESI) were employed for comparative analysis of the navel orange tissue samples by mass spectrometry...
June 19, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28627748/on-line-reaction-monitoring-by-mass-spectrometry-modern-approaches-for-the-analysis-of-chemical-reactions
#14
REVIEW
Andrew Ray, Tony Bristow, Chris Whitmore, Jackie Mosely
The application of on-line mass spectrometry for direct analysis of chemical and other types of process continues to grow in importance and impact. The ability of the technique to characterize many aspects of a chemical reaction such as product and impurity formation, along with reactant consumption in a single experiment is key to its adoption and development. Innovations in ionization techniques and mass spectrometry instrumentation are enabling this adoption. An increasing range of ambient ionization techniques make on-line mass spectrometry applicable to a large range of chemistries...
June 19, 2017: Mass Spectrometry Reviews
https://www.readbyqxmd.com/read/28625676/comprehensive-determination-of-macrolide-antibiotics-their-synthesis-intermediates-and-transformation-products-in-wastewater-effluents-and-ambient-waters-by-liquid-chromatography-tandem-mass-spectrometry
#15
Ivan Senta, Ivona Krizman-Matasic, Senka Terzic, Marijan Ahel
Macrolide antibiotics are a prominent group of emerging contaminants frequently found in wastewater effluents and wastewater-impacted aquatic environments. In this work, a novel analytical method for simultaneous determination of parent macrolide antibiotics (azithromycin, erythromycin, clarithromycin and roxithromycin), along with their synthesis intermediates, byproducts, metabolites and transformation products in wastewater and surface water was developed and validated. Samples were enriched using solid-phase extraction on Oasis HLB cartridges and analyzed by reversed-phase liquid chromatography coupled to electrospray ionization tandem mass spectrometry...
August 4, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28613832/monitoring-the-on-surface-synthesis-of-graphene-nanoribbons-by-mass-spectrometry
#16
Wen Zhang, Zongping Chen, Bo Yang, Xiao-Ye Wang, Reinhard Berger, Akimitsu Narita, Gabriela Borin Barin, Pascal Ruffieux, Roman Fasel, Xinliang Feng, Hans Joachim Räder, Klaus Müllen
We present a mass spectrometric approach to characterize and monitor the intermediates of graphene nanoribbon (GNR) formation by chemical vapor deposition (CVD) on top of Au(111) surfaces. Information regarding the repeating units, lengths, and termini can be obtained directly from the surface sample by a modified matrix-assisted laser desorption/ionization (MALDI) method. The mass spectrometric results reveal ample oxidative side reactions under CVD conditions that can be drastically diminished by the introduction of protective H2 gas at ambient pressure...
June 28, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28605022/forensic-analysis-of-stains-on-fabric-using-direct-analysis-in-real-time-ionization-with-high-resolution-accurate-mass-mass-spectrometry
#17
Sara E Kern, John B Crowe, Jonathan J Litzau, Douglas T Heitkemper
A rapid technique using direct analysis in real-time (DART) ambient ionization coupled to a high-resolution accurate mass-mass spectrometer (HRAM-MS) was employed to analyze stains on an individual's pants suspected to have been involved in a violent crime. The victim was consuming chocolate ice cream at the time of the attack, and investigators recovered the suspect's pants exhibiting splatter stains. Liquid chromatography with mass spectral detection (LC-MS) and stereoscopic light microscopy (SLM) were also utilized in this analysis...
June 12, 2017: Journal of Forensic Sciences
https://www.readbyqxmd.com/read/28601765/application-of-volumetric-absorptive-microsampling-device-for-quantification-of-tacrolimus-in-human-blood-as-a-model-drug-of-high-blood-cell-partition
#18
Kenji Kita, Yuji Mano
Volumetric absorptive microsampling device (VAMS) was evaluated for bioanalysis of tacrolimus, which was used as a model drug with high blood cell partition. Aliquots of blood (ca. 10μL) with different hematocrits and fortified with tacrolimus were wicked up by VAMS and tacrolimus was extracted with a methanol-water mixture (1:1, v/v) via sonication. After chromatography on an AQUITY UPLC HSS T3 column (100×2.1 i.d., mm, 1.8μm), tacrolimus and the internal standard ascomycin, were detected in the positive ion mode with electrospray ionization by monitoring of transitions m/z 826...
September 5, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28581554/-ag59-2-5-dcbt-32-3-a-new-cluster-and-a-precursor-for-three-well-known-clusters
#19
Esma Khatun, Atanu Ghosh, Debasmita Ghosh, Papri Chakraborty, Abhijit Nag, Biswajit Mondal, Sudhakar Chennu, Thalappil Pradeep
We report the synthesis of a new silver cluster, [Ag59(2,5-DCBT)32](3-) (I) (2,5-DCBT: 2,5-dichlorobenzenethiol), which acts as a precursor for the synthesis of three well-known silver clusters, [Ag44(2,4-DCBT/4-FTP)30](4-) (II) (4-FTP: 4-fluorothiophenol and 2,4-DCBT: 2,4-dichlorobenzenethiol), [Ag25(2,4-DMBT)18](-) (III) (2,4-DMBT: 2,4-dimethylbenzenethiol) and [Ag29(1,3-BDT)12(PPh3)4](3-) (IV) (1,3-BDT: 1,3-benzenedithiol and PPh3: triphenylphosphine). This newly synthesized silver cluster, I, is characterized using UV-vis absorption studies, high resolution electrospray ionization mass spectrometry (ESI MS) and other analytical tools...
June 5, 2017: Nanoscale
https://www.readbyqxmd.com/read/28573080/rapid-identification-of-psychoactive-drugs-in-drained-gastric-lavage-fluid-and-whole-blood-specimens-of-drug-overdose-patients-using-ambient-mass-spectrometry
#20
Chi-Wei Lee, Hung Su, You-Da Cai, Ming-Tsang Wu, Den-Chyang Wu, Jentaie Shiea
Psychoactive drug overdoses are life-threatening and require prompt and proper treatment in the emergency room to minimize morbidity and mortality. Prompt identification of the ingested psychoactive drugs is challenging, since witness recall is unreliable and patients' symptoms do not necessarily explain their loss of consciousness. Gas and liquid chromatography mass spectrometric analyses have been the traditionally employed methods to detect and identify abused substances; however, these techniques are time-consuming and labor-intensive...
2017: Mass Spectrometry
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