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Ambient ionization

Claudia Spatari, Wenlong Li, Alfred H Schinkel, Gaetano Ragno, Jan H M Schellens, Jos H Beijnen, Rolf W Sparidans
A bio-analytical assay for the first third generation ALK inhibitor lorlatinib in mouse plasma was developed and validated. Ten-μl plasma samples were prepared by adding rucaparib as the internal standard and precipitation of the plasma proteins. For LC-MS/MS analysis, compounds were eluted at 0.5 mL/min and separated on a 3-μm particle-size, polar embedded octadecyl silica column by gradient elution using 0.1% of formic acid (in water) and methanol. Compounds were monitored with positive electrospray ionization using a triple quadrupole mass spectrometer in selected reaction monitoring mode...
March 9, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Alfredo Mirandola, Giuseppe Magro, Marco Lavagno, Andrea Mairani, Silvia Molinelli, Stefania Russo, Edoardo Mastella, Alessandro Vai, Davide Maestri, Vanessa La Rosa, Mario Ciocca
PURPOSE: To dosimetrically characterize a multi-layer ionization chamber (MLIC) prototype for quality assurance (QA) of pristine integral ionization curves (ICs) and spread-out-Bragg-peaks (SOBPs) for scanning light ion beams. METHODS: QUBE (De.Tec.Tor., Torino, Italy) is a modular detector designed for QA in particle therapy (PT). Its main module is a MLIC detector, able to evaluate particle beam relative depth ionization distributions at different beam energies and modulations...
March 14, 2018: Medical Physics
Morgann Berg, Jason M Kephart, Amit Munshi, Walajabad S Sampath, Taisuke Ohta, Calvin Chan
Postdeposition CdCl2 treatment of polycrystalline CdTe is known to increase the photovoltaic device efficiency. However, the precise chemical, structural, and electronic changes that underpin this improvement are still debated. In this study, spectroscopic photoemission electron microscopy was used to spatially map the vacuum level and ionization energy of CdTe films, enabling the identification of electronic structure variations between grains and grain boundaries (GBs). In vacuo preparation and inert transfer of oxide-free CdTe surfaces isolated the separate effects of CdCl2 treatment and ambient oxygen exposure...
March 12, 2018: ACS Applied Materials & Interfaces
Pallab Basuri, Depanjan Sarkar, Ganesan Paramasivam, Thalappil Pradeep
Here we introduce a new ambient ionization technique named as laser assisted paper spray ionization mass spectrometry (LAPSI MS). In it, a 532 ± 10 nm, ≤10 mW laser pointer was shone on a triangularly cut paper along with high voltage, to effect ionization. The analyte solution was continuously pushed through a fused silica capillary, using a syringe pump, at a preferred infusion rate. LAPSI MS promises enhanced ionization with high signal intensity of polycyclic aromatic hydrocarbons (PAHs), which are normally not ionizable with similar ionization methods involving solvent sprays...
March 9, 2018: Analytical Chemistry
Hong Zhang, Kai Yu, Na Li, Jing He, Hong You, Jie Jiang
Reactive intermediates play key roles for reaction mechanism elucidation. A suitable tool for identifying the key intermediates is crucial and highly desirable. In this study, surface desorption dielectric-barrier discharge ionization (Reactive SDDBDI) was developed for characterization of the reactive intermediates. In reactive SDDBDI, the plasma is doped with a reagent before the plasma ions are directed at a cover slip surface bearing another analyte. Different from SDDBDI, reactive SDDBDI can be used both as an ambient ionization source and as a means to produce reagent ions for ambient ion/molecule reactions...
March 9, 2018: Journal of Mass Spectrometry: JMS
Kei Zaitsu, Yumi Hayashi, Tasuku Murata, Kazumi Yokota, Tomomi Ohara, Maiko Kusano, Hitoshi Tsuchihashi, Tetsuya Ishikawa, Akira Ishii, Koretsugu Ogata, Hiroshi Tanihata
Recent improvements in ambient ionization techniques combined with mass spectrometry has enabled to achieve real-time monitoring of analytes of interest, even for biogenic molecules in living animals. Here, we demonstrate a newly-developed system for in vivo real-time monitoring of metabolites in a living mouse brain. It consists of a semi-automated manipulation system and a unique probe electrospray ionization unit, which uses an extremely thin solid needle (tip dia.: 700 nm) for direct sampling and ionization, coupled to a conventional tandem mass spectrometer...
March 9, 2018: Analytical Chemistry
Zhongquan Li, Fang Zhang, Junbo Zhao, Xiaopan Liu, Xiuping Chen, Yue Su, Yinlong Guo
Ambient flame ionization (AFI) coupled with triple quadrupole tandem mass spectrometry was developed for quantitative analysis of sodium saccharin (SAC) in various food samples. Typically, the micro-flame by the combustion of n-butane provided a heating zone for fast desorption and ionization of analytes in milliseconds. Then high ion abundance of analyte could be produced in a short time, which made AFI-MS possess a very high sensitivity for SAC detection and was particularly appropriate for the quantification in multiple reaction monitor (MRM) mode...
May 15, 2018: Talanta
Anyin Li, Martin R L Paine, Stephen Zambrzycki, Rachel Stryffeler, Jason Wu, Marcos Bouza, Jake Huckaby, Chu-Yin Chang, Manoj Kumar, Piyoosh Mukhija, Facundo M Fernandez
Many technologies currently exist that are capable of analyzing the surface of solid samples under ambient or vacuum conditions, but they are typically limited to smooth, planar surfaces. Those few that can be applied to non-planar surfaces, however, require manual sampling and a high degree of human intervention. Herein, we describe a new platform, Robotic Surface Analysis Mass Spectrometry (RoSA-MS), for direct surface sampling of three-dimensional (3D) objects. In RoSA-MS, a sampling probe is attached to a robotic arm that has 360° rotation through 6 individual joints...
March 1, 2018: Analytical Chemistry
Yu-Ying Chao, Yen-Ling Chen, Wei-Chu Chen, Bai-Hsiun Chen, Yeou-Lih Huang
Ambient mass spectrometry using an interchangeable thermal desorption/electrospray ionization source (TD-ESI) is a relatively new technique that has had only a limited number of applications to date. Nevertheless, this direct-analysis technique has potential for wider use in analytical chemistry (e.g., in the rapid direct detection of contaminants, residues, and adulterants on and in food) when operated in dual-working mode (pretreatment-free qualitative screening and conventional quantitative confirmation) after switching to a TD-ESI source from a conventional ESI source...
June 30, 2018: Food Chemistry
A Astuto, S S Fernandes, K C S Patrão, E S Fonseca, W W Pereira, R T Lopes
The standard thermal neutron flux unit, TNF2, in the Brazilian National Ionizing Radiation Metrology Laboratory was rebuilt. Fluence is still achieved by moderating of four 241Am-Be sources with 0.6 TBq each. The facility was again simulated and redesigned with graphite core and paraffin added graphite blocks surrounding it. Simulations using the MCNPX code on different geometric arrangements of moderator materials and neutron sources were performed. The resulting neutron fluence quality in terms of intensity, spectrum and cadmium ratio was evaluated...
February 21, 2018: Radiation Protection Dosimetry
Eda Gjika, Sonali Pal-Ghosh, Anna Tang, Megan Kirschner, Gauri Tadvalkar, Jerome Canady, Mary Ann Stepp, Michael Keidar
Cold atmospheric plasma (CAP), an ionized gas operated at near ambient temperature has been introduced as a new therapeutic opportunity for treating cancers. The effectiveness of the therapy has been linked to CAP generated reactive oxygen and nitrogen species such as hydrogen peroxide and nitrite. In this study, we monitor in real time cancer cell response to CAP over the course of 48 hours. The results demonstrate a correlation between cell viability, exposure time (30, 60, 90, 180-s) and discharge voltage (3...
February 23, 2018: ACS Applied Materials & Interfaces
Laurent Bernier, Harry Pinfold, Matthias Pauly, Stephan Rauschenbach, Julius Reiss
Transfer capillaries are the preferred means to transport ions, generated by electrospray ionization, from ambient conditions to vacuum. During the transfer of ions through the narrow, long tubes into vacuum, substantial losses are typical. However, recently it was demonstrated that these losses can be avoided altogether. To understand the experimental observation and provide a general model for the ion transport, here, we investigate the ion transport through capillaries by numerical simulation of interacting ions...
February 21, 2018: Journal of the American Society for Mass Spectrometry
Alexander Schütz, Felipe J Lara-Ortega, Felix David Klute, Sebastian Brandt, Michael Schilling, Antje Michels, Damir Veza, Vlasta Horvatic, Juan F Garcia-Reyes, Joachim Franzke
Dielectric barrier discharges (DBDs) have been used as soft ionization sources (DBDI) for organic mass spectrometry (DBDI-MS) for approximately ten years. Helium-based DBDI is often used because of its good ionization efficiency, low ignition voltage and homogenous plasma conditions. Argon needs much higher ignition voltages than helium when the same discharge geometry is used. A filamentary plasma, which is not suitable for soft ionization, may be produced instead of a homogenous plasma. This difference results in N2, present in helium and argon as an impurity, being Penning-ionized by helium but not by metastable argon atoms...
February 20, 2018: Analytical Chemistry
Jennifer L Berry, Douglas A Day, Tim Elseberg, Brett B Palm, Weiwei Hu, Aroob Abdelhamid, Jason C Schroder, Uwe Karst, Jose L Jimenez, Eleanor C Browne
Mass spectrometry imaging is becoming an increasingly common analytical technique due to its ability to provide spa-tially resolved chemical information. Here, we report a novel imaging approach combining laser ablation with two mass spectrometric techniques, aerosol mass spectrometry and chemical ionization mass spectrometry, separately and in parallel. Both mass spectrometric methods provide the fast response, rapid data acquisition, low detection limits, and high-resolution peak separation desirable for imaging complex samples...
February 20, 2018: Analytical Chemistry
Yu-Ying Chao, Yen-Ling Chen, Hong-Yi Lin, Yeou-Lih Huang
Thermal desorption electrospray ionization/mass spectrometry (TD-ESI-MS) employing a quickly interchangeable ionization source is a relatively new ambient ionization mass spectrometric technique that has had, to date, only a limited number of applications related to food safety control. With reallocation of resources, this direct-analysis technique has had wider use in food analysis when operated in dual-working mode (pretreatment-free qualitative screening and conventional quantitative confirmation) after switching to an ambient ionization source from a traditional atmospheric pressure ionization source...
June 20, 2018: Analytica Chimica Acta
Stefanie Pleik, Bernhard Spengler, Dhaka Ram Bhandari, Steven Luhn, Thomas Schäfer, Dieter Urbach, Dieter Kirsch
In forensic science, reconstructing the timing of events occurring during a criminal offense is of great importance. In some cases, the time when particular evidence was left on a crime scene is a critical matter. The ability to estimate the fingerprint age would raise the evidentiary value of fingerprints tremendously. For this purpose the most promising approach is the analysis of changes in the chemical compositions of fingerprint residues in the course of aging. The focus of our study is the identification of human specific compounds in fingerprint residues, characterized by a significant aging behavior that could analytically be used for the age determination of fingerprints in future...
February 12, 2018: Analyst
Yanhao Zhang, Ruijin Li, Jing Fang, Chen Wang, Zongwei Cai
A new atmospheric pressure gas chromatography-tandem mass spectrometry (APGC-MS/MS) was developed to simultaneously separate, identify and quantify 18 nitro-polyaromatic hydrocarbons (NPAHs) in air fine particulate matter (PM2.5). Compared with traditional negative chemical ionization (NCI) or electron impact ionization (EI)-MS/MS methods, APGC-MS/MS equipped with an atmospheric pressure chemical ionization (APCI) source provided better sensitivity and selectivity for NPAHs analysis in PM2.5.18 NPAHs were completely separated, and satisfactory linear response (R2 > 0...
February 2, 2018: Chemosphere
Jussi Huikari, Teemu Siiskonen, Antti Kosunen, Panu Pousi
Radiation metrology laboratory at Radiation and Nuclear Safety Authority (STUK) is Finnish national laboratory for ionizing radiation. In order to establish personal dose equivalent available for neutron calibration service, a project was started to evaluate the neutron reference fields in the present facility. The irradiation room conditions were characterized in order to establish reference conditions for personal dose equivalent. To verify the validity of the calculations, ambient dose equivalent rates and room return were measured and calculated for 241AmBe and 252Cf sources...
February 3, 2018: Radiation Protection Dosimetry
Anna L M C Malthez, Barbara Marczewska, Felisberto Ferreira, Nancy K Umisedo, Tomasz Nowak, Pawel Bilski, Elisabeth M Yoshimura
Calcium fluoride (CaF2), in both natural and synthetic forms, has been exhaustively studied and explored as thermoluminescent (TL) detector. However its sensitivity to ambient light points to the applicability of CaF2 as OSL (Optically Stimulated Luminescence) detector, increasing the research about its luminescent properties. Although some properties to employ CaF2 detectors with OSL technique have been already demonstrated, there is a lack of some essential information as the OSL response to different types and energy of ionizing radiation...
January 31, 2018: Applied Radiation and Isotopes
F Judée, S Simon, C Bailly, T Dufour
Cold atmospheric plasmas are weakly ionized gases that can be generated in ambient air. They produce energetic species (e.g. electrons, metastables) as well as reactive oxygen species, reactive nitrogen species, UV radiations and local electric field. Their interaction with a liquid such as tap water can hence change its chemical composition. The resulting "plasma-activated liquid" can meet many applications, including medicine and agriculture. Consequently, a complete experimental set of analytical techniques dedicated to the characterization of long lifetime chemical species has been implemented to characterize tap water treated using cold atmospheric plasma process and intended to agronomy applications...
December 20, 2017: Water Research
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