Principles of Operation of a Rotating Wall Mass Analyzer for Preparative Mass Spectrometry

2020 ◽  
Vol 31 (9) ◽  
pp. 1875-1884
Author(s):  
Pei Su ◽  
Michael F. Espenship ◽  
Julia Laskin
Keyword(s):  
Mass Spectrometry ◽  
Mass Analyzer ◽  
Rotating Wall ◽  
Wall Mass

Preparative Mass Spectrometry Using a Rotating‐Wall Mass Analyzer

2020 ◽  
Vol 59 (20) ◽  
pp. 7711-7716 ◽  
Author(s):  
Pei Su ◽  
Hang Hu ◽  
Daisy Unsihuay ◽  
Di Zhang ◽  
Tiziano Dainese ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Mass Analyzer ◽  
Rotating Wall ◽  
Wall Mass

Preparative Mass Spectrometry Using a Rotating‐Wall Mass Analyzer

2020 ◽  
Vol 132 (20) ◽  
pp. 7785-7790
Author(s):  
Pei Su ◽  
Hang Hu ◽  
Daisy Unsihuay ◽  
Di Zhang ◽  
Tiziano Dainese ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Mass Analyzer ◽  
Rotating Wall ◽  
Wall Mass

Simultaneous Quantification of Pantoprazole and Levosulpiride in Spiked Human Plasma Using High Performance Liquid Chromatography Tandem Mass Spectrometry

2018 ◽  
Vol 15 (1) ◽  
pp. 17-23
Author(s):  
Vulli Srinandan ◽  
Krishnaveni Nagappan ◽  
Sonam Patel ◽  
Karthik Yamjala ◽  
Gowramma Byran ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Human Plasma ◽  
Mass Analyzer ◽  
Tandem Mass ◽  
Preparation Technique ◽  
Spiked Human Plasma ◽  
Simultaneous Quantification ◽  
Electro Spray Ionization

Background: Pantoprazole (PTZ) and Levosulpiride (LS) were proven as effective agents for the treatment of Gastro-Esophageal Reflux Disease (GERD). It is a complex motor disorder that results in regurgitation of the gastric contents into the lower esophagus with consequent symptoms such as heart burn, retrosternal pain, dysphagia and belching. Methods: A rapid, sensitive, selective and specific liquid chromatography- electro spray ionization tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneous quantification of Pantoprazole (PTZ) and Levosulpiride (LS) in spiked Human Plasma. The method utilized SPE as sample preparation technique and the analysis was carried out on a HPLC system utilizing electro spray ionization as interface and triple quadrupole mass analyzer for quantification in MRM possitive mode. Iloperidone was used as internal standard (IS). Chromatographic separation was performed on a Phenomenex C-18 Column (4.6 mm x 50 mm, 5µ) with an isocratic elution mode utilizing a mobile phase composition of Solution containing a mixture of 70 volumes of acetonitrile: 30 volumes of methanol and 10mM ammonium formate (pH 4.0) at the ratio of 80:20 % v/v. The flow rate was maintained at 0.3 mL/min. Results: PTZ, LS and IS were detected and quantified with proton adducts at m/z 383.37→200.00, m/z 341.42→112.15 and 426.48→261.00 respectively. The linearity and range was established by fortifying blank plasma samples in the concentration range of 3.5-2000 ng/mL for PTZ and 3.0-2400 ng/mL for LS. The correlation coefficient (r2) was found to be ≥ 0.993 for PTZ and (r2) ≥ 0.990 for LS. The lower limit of quantification for PTZ was 3.5 ng/mL and LS was 3.0 ng/mL. The intra and inter day precision and accuracy for PTZ and LS were within the limits fulfilling the international acceptance criteria. PTZ and LS were found to be stable throughout three freeze-thaw cycles, bench top and short term stability studies. Conclusion: The proposed validated LC-MS/MS method offers a sensitive quantification of PTZ and LS in spiked human plasma and can be utilized for the quantification of PTZ and LS in real-time samples.

Mass Selected ZEKE-Spectra of FeC2-Anions: A Spectroscopic Access to Intermediates in Catalytic Reactions of Hydrocarbons on Metal Surfaces

1994 ◽  
Vol 49 (12) ◽  
pp. 1256-1258 ◽  
Author(s):  
G. Drechsler ◽  
C. Bäßmann ◽  
U. Boesl ◽  
E. W. Schlag
Keyword(s):  
Mass Spectrometry ◽  
Photoelectron Spectroscopy ◽  
Metal Surfaces ◽  
Catalytic Reactions ◽  
Photoelectron Spectra ◽  
Mass Analyzer ◽  
Flight Mass Spectrometry ◽  
New Information ◽  
Zero Kinetic Energy ◽  
Conventional Laser

Abstract Zero-kinetic-energy (ZEKE) photoelectron spectra of metalcarbide anions are presented, allowing a high resolu­tion spectroscopic access to intermediates in catalytic reac­tions of hydrocarbons on metal surfaces. As a first compound, FeC2 (an intermediate of the iron/acetylene system) has been chosen. Important for successful ZEKE spectroscopy was a special anion source and the selection by time-of-flight mass spectrometry. In addition, conventional laser induced photo­ detachment photoelectron spectroscopy in combination with our anion source and mass analyzer delivered valuable new information.

scholarly journals Determination of N-Nitrosamines by Gas Chromatography Coupled to Quadrupole–Time-of-Flight Mass Spectrometry in Water Samples

Separations ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 3 ◽  
Author(s):  
Benigno José Sieira ◽  
Inmaculada Carpinteiro ◽  
Rosario Rodil ◽  
José Benito Quintana ◽  
Rafael Cela
Keyword(s):  
Mass Spectrometry ◽  
Environmental Protection Agency ◽  
Ion Trap ◽  
Solid Phase ◽  
Classical Method ◽  
Tap Water ◽  
Time Of Flight ◽  
The United States ◽  
Mass Analyzer

An analytical method based on high-resolution quadrupole–time-of-flight (QToF) mass spectrometry has been developed as an alternative to the classical method, using a low-resolution ion trap (IT) analyzer to reduce interferences in N-nitrosamines determination. Extraction of the targeted compounds was performed by solid-phase extraction (SPE) following the United States Environmental Protection Agency (USEPA) -521 method. First, both electron impact (EI) and positive chemical ionization (PCI) using methane as ionization gas were compared, along with IT and QToF detection. Then, parameters such as limits of detection (LOD) and quantification (LOQ), linearity, and repeatability were assessed. The results showed that the QToF mass analyzer combined with PCI was the best system for the determination of the N-nitrosamines, with instrumental LOD and LOQ in the ranges of 0.2–4 and 0.6–11 ng mL−1, respectively, which translated into method LOD and LOQ in the ranges of 0.2–1.3 and 0.6–3.9 ng L−1, respectively. The analysis of real samples showed the presence of 6 of the N-nitrosamines in influent, effluent, and tap water. N-nitrosodimethylamine (NDMA) was quantified in all the analyzed samples at concentrations between 1 and 27 ng L−1. Moreover, four additional nitrosamines were found in tap and wastewater samples.

A linear time-of-flight mass analyzer for thermal ionization cavity mass spectrometry

2001 ◽  
Vol 56 (7) ◽  
pp. 1175-1194 ◽  
Author(s):  
David M. Wayne ◽  
Wei Hang ◽  
Diane K. McDaniel ◽  
Robert E. Fields ◽  
Eddie Rios ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Linear Time ◽  
Time Of Flight ◽  
Thermal Ionization ◽  
Mass Analyzer

scholarly journals Effects of modular ion-funnel technology onto analysis of breath VOCs by means of real-time mass spectrometry

2020 ◽  
Vol 412 (26) ◽  
pp. 7131-7140
Author(s):  
Giovanni Pugliese ◽  
Felix Piel ◽  
Phillip Trefz ◽  
Philipp Sulzer ◽  
Jochen K. Schubert ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Real Time ◽  
Human Subjects ◽  
Proton Transfer Reaction ◽  
Mass Analyzer ◽  
Real Time Monitoring ◽  
Healthy Human ◽  
Flight Mass Spectrometry ◽  
Ion Funnel ◽  
Tof Ms

Abstract Proton transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) is a powerful tool for real-time monitoring of trace concentrations of volatile organic compounds (VOCs). The sensitivity of PTR-ToF-MS also depends on the ability to effectively focus and transmit ions from the relatively high-pressure drift tube (DT) to the low-pressure mass analyzer. In the present study, a modular ion-funnel (IF) is placed adjacent to the DT of a PTR-ToF-MS instrument to improve the ion-focusing. IF consists of a series of electrodes with gradually decreasing orifice diameters. Radio frequency (RF) voltage and direct current (DC) electric field are then applied to the electrodes to get the ions focused. We investigated the effect of the RF voltage and DC field on the sensitivity of a pattern of VOCs including hydrocarbons, alcohols, aldehydes, ketones, and aromatic compounds. In a proof-of-concept study, the instrument operating both as normal DT (DC-mode) and at optimal IF conditions (RF-mode) was applied for the breath analysis of 21 healthy human subjects. For the range of investigated VOCs, an improvement of one order of magnitude in sensitivity was observed in RF-mode compared with DC-mode. Limits of detection could be improved by a factor of 2–4 in RF-mode compared with DC-mode. Operating the instrument in RF-mode allowed the detection of more compounds in the exhaled air compared with DC-mode. Incorporation of the IF considerably improved the performance of PTR-ToF-MS allowing the real-time monitoring of a larger number of potential breath biomarkers.

scholarly journals Evaluation of analytical methods to address Tungsten speciation

2013 ◽  
Vol 11 (3) ◽  
pp. 308-317 ◽  
Keyword(s):  
Mass Spectrometry ◽  
Raman Spectroscopy ◽  
Aqueous Solutions ◽  
Aging Time ◽  
Analytical Methods ◽  
Dominant Species ◽  
Narrow Range ◽  
Mass Analyzer ◽  
Ionization Mass ◽  
Desorption Ionization

Tungsten in solution may exist as a wide variety of species depending on concentration, pH, and aging time. Despite a substantial number of studies on this topic, the speciation of tungsten in aqueous solutions is still not completely understood. To address issues of fate, transport and potential bioavailability, it is necessary to be able to assess the speciation of tungsten in environmental systems. This study investigates the use of Laser Desorption/Ionization mass spectrometry combined with a Time-of-Flight mass analyzer (LDITOF) as well as Raman spectroscopy as potential techniques in speciation studies. Raman spectroscopy has been successful in identifying the dominant species under a narrow range of conditions. The ultimate goal is to extend the range of conditions and concentrations while also identifying subordinate species.

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