scholarly journals Study of Controlled Atmosphere Flexible Microtube Plasma Soft Ionization Mass Spectrometry for Detection of Volatile Organic Compounds as Potential Biomarkers in Saliva for Cancer

2020 ◽  
Vol 92 (14) ◽  
pp. 9722-9729
Author(s):  
Pascal Vogel ◽  
Constantinos Lazarou ◽  
Odhisea Gazeli ◽  
Sebastian Brandt ◽  
Joachim Franzke ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Controlled Atmosphere ◽  
Soft Ionization ◽  
Volatile Organic ◽  
Potential Biomarkers

Real time analysis of trace volatile organic compounds in ambient air: a comparison between membrane inlet single photon ionization mass spectrometry and proton transfer reaction mass spectrometry

2020 ◽  
Vol 12 (35) ◽  
pp. 4343-4350
Author(s):  
Zhujun Yu ◽  
Chao Liu ◽  
Hongzhi Niu ◽  
Manman Wu ◽  
Wei Gao ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Volatile Organic Compounds ◽  
Real Time ◽  
Organic Compounds ◽  
Single Photon ◽  
Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Single Photon Ionization ◽  
Volatile Organic ◽  
Photon Ionization

Membrane single photon ionization mass spectrometry enables real-time monitoring of volatile organic compounds at trace levels, providing important complementary information on aromatics and alkanes in the air.

scholarly journals Using collision-induced dissociation to constrain sensitivity of ammonia chemical ionization mass spectrometry (NH<sub>4</sub><sup>+</sup> CIMS) to oxygenated volatile organic compounds

2019 ◽  
Vol 12 (3) ◽  
pp. 1861-1870 ◽  
Author(s):  
Alexander Zaytsev ◽  
Martin Breitenlechner ◽  
Abigail R. Koss ◽  
Christopher Y. Lim ◽  
James C. Rowe ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Mass Spectrometer ◽  
Chemical Ionization ◽  
Chemical Ionization Mass Spectrometry ◽  
Collision Induced Dissociation ◽  
Ionization Mass ◽  
Oxygenated Volatile Organic Compounds ◽  
Volatile Organic

Abstract. Chemical ionization mass spectrometry (CIMS) instruments routinely detect hundreds of oxidized organic compounds in the atmosphere. A major limitation of these instruments is the uncertainty in their sensitivity to many of the detected ions. We describe the development of a new high-resolution time-of-flight chemical ionization mass spectrometer that operates in one of two ionization modes: using either ammonium ion ligand-switching reactions such as for NH4+ CIMS or proton transfer reactions such as for proton-transfer-reaction mass spectrometer (PTR-MS). Switching between the modes can be done within 2 min. The NH4+ CIMS mode of the new instrument has sensitivities of up to 67 000 dcps ppbv−1 (duty-cycle-corrected ion counts per second per part per billion by volume) and detection limits between 1 and 60 pptv at 2σ for a 1 s integration time for numerous oxygenated volatile organic compounds. We present a mass spectrometric voltage scanning procedure based on collision-induced dissociation that allows us to determine the stability of ammonium-organic ions detected by the NH4+ CIMS instrument. Using this procedure, we can effectively constrain the sensitivity of the ammonia chemical ionization mass spectrometer to a wide range of detected oxidized volatile organic compounds for which no calibration standards exist. We demonstrate the application of this procedure by quantifying the composition of secondary organic aerosols in a series of laboratory experiments.

scholarly journals Development and validation of a portable gas phase standard generation and calibration system for volatile organic compounds

2010 ◽  
Vol 3 (3) ◽  
pp. 683-691 ◽  
Author(s):  
P. Veres ◽  
J. B. Gilman ◽  
J. M. Roberts ◽  
W. C. Kuster ◽  
C. Warneke ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Volatile Organic Compounds ◽  
Organic Carbon ◽  
Proton Transfer ◽  
Gas Phase ◽  
Organic Compounds ◽  
Total Carbon ◽  
Ionization Mass ◽  
Calibration System ◽  
Volatile Organic

Abstract. We report on the development of an accurate, portable, dynamic calibration system for volatile organic compounds (VOCs). The Mobile Organic Carbon Calibration System (MOCCS) combines the production of gas-phase VOC standards using permeation or diffusion sources with quantitative total organic carbon (TOC) conversion on a palladium surface to CO2 in the presence of oxygen, and the subsequent CO2 measurement. MOCCS was validated using three different comparisons: (1) TOC of high accuracy methane standards compared well to expected concentrations (3% relative error), (2) a gas-phase benzene standard was generated using a permeation source and measured by TOC and gas chromatography mass spectrometry (GC-MS) with excellent agreement (<4% relative difference), and (3) total carbon measurement of 4 known gas phase mixtures were performed and compared to a calculated carbon content to agreement within the stated uncertainties of the standards. Measurements from laboratory biomass burning experiments of formic acid by negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS) and formaldehyde by proton transfer reaction-mass spectrometry (PTR-MS), both calibrated using MOCCS, were compared to open path Fourier transform infrared spectroscopy (OP-FTIR) to validate the MOCCS calibration and were found to compare well (R2 of 0.91 and 0.99, respectively).

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