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Atmospheric Pressure Dark-Current Argon Discharge Ionization with Comparable Performance to Direct Analysis in Real Time Mass Spectrometry
Herein, a dark-current discharge state created by combining argon flow with a needle electrode in ambient air is described that has an ionization efficiency and mechanism comparable to those of conventional helium direct analysis in real time (DART), without requiring dopants and DART glow discharge...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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The Mass Spectrometry Society of Japan
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6861550/ https://www.ncbi.nlm.nih.gov/pubmed/31840015 http://dx.doi.org/10.5702/massspectrometry.A0075 |
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author | Sekimoto, Kanako Sakakura, Motoshi Hike, Hiroshi Kawamukai, Takatomo Shiota, Teruhisa Takayama, Mitsuo |
author_facet | Sekimoto, Kanako Sakakura, Motoshi Hike, Hiroshi Kawamukai, Takatomo Shiota, Teruhisa Takayama, Mitsuo |
author_sort | Sekimoto, Kanako |
collection | PubMed |
description | Herein, a dark-current discharge state created by combining argon flow with a needle electrode in ambient air is described that has an ionization efficiency and mechanism comparable to those of conventional helium direct analysis in real time (DART), without requiring dopants and DART glow discharge. Using this method, polar compounds such as α-amino acids were ionized in the dark-current argon discharge via (de)protonation, molecular anion formation, fragmentation, (de)protonation with the attachment of oxygen, deprotonation with hydrogen loss and negative ion attachment. In contrast, nonpolar compounds (e.g., n-alkanes) were detected as positive ions via hydride abstraction and oxidation. Major background ions observed were H(3)O(+)(H(2)O)(n), O(2)(·+), O(2)(·−)(H(2)O)(n) and CO(3)(·−). These results indicate that the present dark-current discharge efficiently generates resonance-state argon with an internal energy of ∼14.2 eV, higher than that of the well-known metastable state (∼11.6 eV). It is therefore suggested that ionization reactions occurring there can be attributed to the Penning ionization of atmospheric H(2)O and O(2) by resonance-state argon, analogous to helium DART. |
format | Online Article Text |
id | pubmed-6861550 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | The Mass Spectrometry Society of Japan |
record_format | MEDLINE/PubMed |
spelling | pubmed-68615502019-12-13 Atmospheric Pressure Dark-Current Argon Discharge Ionization with Comparable Performance to Direct Analysis in Real Time Mass Spectrometry Sekimoto, Kanako Sakakura, Motoshi Hike, Hiroshi Kawamukai, Takatomo Shiota, Teruhisa Takayama, Mitsuo Mass Spectrom (Tokyo) Original Article Herein, a dark-current discharge state created by combining argon flow with a needle electrode in ambient air is described that has an ionization efficiency and mechanism comparable to those of conventional helium direct analysis in real time (DART), without requiring dopants and DART glow discharge. Using this method, polar compounds such as α-amino acids were ionized in the dark-current argon discharge via (de)protonation, molecular anion formation, fragmentation, (de)protonation with the attachment of oxygen, deprotonation with hydrogen loss and negative ion attachment. In contrast, nonpolar compounds (e.g., n-alkanes) were detected as positive ions via hydride abstraction and oxidation. Major background ions observed were H(3)O(+)(H(2)O)(n), O(2)(·+), O(2)(·−)(H(2)O)(n) and CO(3)(·−). These results indicate that the present dark-current discharge efficiently generates resonance-state argon with an internal energy of ∼14.2 eV, higher than that of the well-known metastable state (∼11.6 eV). It is therefore suggested that ionization reactions occurring there can be attributed to the Penning ionization of atmospheric H(2)O and O(2) by resonance-state argon, analogous to helium DART. The Mass Spectrometry Society of Japan 2019 2019-10-25 /pmc/articles/PMC6861550/ /pubmed/31840015 http://dx.doi.org/10.5702/massspectrometry.A0075 Text en Copyright © 2019 Kanako Sekimoto, Motoshi Sakakura, Hiroshi Hike, Takatomo Kawamukai, Teruhisa Shiota, and Mitsuo Takayama. http://creativecommons.org/licenses/by/2.5/ This is an open access article distributed under the terms of Creative Commons Attribution License, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes. |
spellingShingle | Original Article Sekimoto, Kanako Sakakura, Motoshi Hike, Hiroshi Kawamukai, Takatomo Shiota, Teruhisa Takayama, Mitsuo Atmospheric Pressure Dark-Current Argon Discharge Ionization with Comparable Performance to Direct Analysis in Real Time Mass Spectrometry |
title | Atmospheric Pressure Dark-Current Argon Discharge Ionization with Comparable Performance to Direct Analysis in Real Time Mass Spectrometry |
title_full | Atmospheric Pressure Dark-Current Argon Discharge Ionization with Comparable Performance to Direct Analysis in Real Time Mass Spectrometry |
title_fullStr | Atmospheric Pressure Dark-Current Argon Discharge Ionization with Comparable Performance to Direct Analysis in Real Time Mass Spectrometry |
title_full_unstemmed | Atmospheric Pressure Dark-Current Argon Discharge Ionization with Comparable Performance to Direct Analysis in Real Time Mass Spectrometry |
title_short | Atmospheric Pressure Dark-Current Argon Discharge Ionization with Comparable Performance to Direct Analysis in Real Time Mass Spectrometry |
title_sort | atmospheric pressure dark-current argon discharge ionization with comparable performance to direct analysis in real time mass spectrometry |
topic | Original Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6861550/ https://www.ncbi.nlm.nih.gov/pubmed/31840015 http://dx.doi.org/10.5702/massspectrometry.A0075 |
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