Development of soft ionization using direct current pulse glow discharge plasma source in mass spectrometry for volatile organic compounds analysis

Nunome, Yoko; Ueki, Yasuaki; Yoshiie, Ryo; Wagatsuma, Kazuaki

doi:10.1016/j.sab.2017.11.002

Cited by 11 publications

(15 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These background ions can be ionized by electron ionization (EI), or by charge-transfer ionization (CT) and Penning-type ionization (PI) with excited N2 molecules. 16,[18][19][20] The NO + and O2 + which are mainly produced are the most active precursor ions because they do not easily react with remaining species of air gas. 21 At a pressure of 1.5 kPa ( Fig.…”

Section: Resultsmentioning

confidence: 99%

“…14 A glow discharge plasma, which is generated between the electrodes, makes it possible to ionize organic components. [15][16][17] Fast electrons released from the mesh cathode are accelerated towards the anode, and then excite/ ionize gas species (G*, G + ) in the plasma region, as shown in Fig. S1 (Supporting Information).…”

Section: Spi-ms Apparatusmentioning

confidence: 99%

“…100 mL min -1 ) to be introduced into the SPI source regardless of the exhaust capacity of the vacuum system, which could generate a stable discharge plasma at pressures of up to several kPa in the SPI source. 16 A DC pulse power supply system comprised a high-speed pulse switching circuit (FHVS-2000, Chubu R & D Co., Ltd., Japan) and a DC power supply (HVR-2K150P/FG/100, Chubu R & D Co., Ltd., Japan), which restricted the average supplied power. Current-voltage characteristic of the pulsed discharge plasma indicated that the discharge voltage remained almost constant regardless of the current values, so that a constantcurrent mode was conducted.…”

Section: Spi-ms Apparatusmentioning

confidence: 99%

“…We have successfully developed a soft plasma ionization (SPI) source for the purpose of direct analysis in mass spectrometry using glow discharge plasma. [14][15][16][17] Glow discharge tube is mostly classified into a parallel flat plate type and a Grimm type (an anode plate and a hollow cathode), while the SPI source has newly designated coaxial cylindrical electrodes composed of a Cu-hollow anode and a Cu-mesh cathode. The glow discharge plasma generated between these electrodes ionizes organic components.…”

Section: Introductionmentioning

confidence: 99%

“…Our previous work has shown that aromatic hydrocarbons can be ionized through the attachment of NO + , which would be derived from ambient air. 16 The reactions of aromatic hydrocarbons with these ions easily occured at a higher pressure (several kPa) in an ambient air discharge. Another study of ours was conducted in an oxidation reaction with saturated hydrocarbons in an air plasma at a pressure of several kPa, indicating that the saturated hydrocarbons were observed as molecular ions, [M+13] + , which could be assigned to an oxidation product, [M+O-3H] + .…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Glow Discharge Plasma Ionization Mass Spectrometry for Direct Detection of Oxygenated Organic Compounds in the Gas-phase

Nunome

Wagatsuma

2019

ANAL. SCI.

Self Cite

View full text Add to dashboard Cite

This study describes a direct analysis of oxygenated organic compounds, such as ketones, esters and ethers, rapidly and easily using a soft plasma ionization (SPI) source combined with a Q-mass spectrometer. A related molecular ion, [2M+H] + , in which a sample molecule (M) can undergo protonation via water clusters, such as [(H2O)n+H] + and [N2(H2O)n+H] + , in an ambient air glow discharge plasma, can be dominantly detected as a base peak with little or no fragmentation at a pressure of several kPa. Oxygenated organic compounds with high proton affinity were found to generate their dimers through the hydrogen bonding interaction at higher pressures. A deuterated solvent was used to examine whether or not the adduct ion of analyte was derived from the solvent. The formation of [2M+H] + strongly depended on the time. A two-dimensional spectrometer was used to obtain the distribution of several excited species and then to confirm the ionization reactions of the analyte in the SPI source. The sample molecule would be readily ionized through Penning-type collisions with excited N2, which causes fragmentation for oxygenated compounds due to the lower pressures (approx. 1.0 kPa) while it is ionized by an attachment with protons from water clusters at higher pressures (several kPa). The SPI source can be a new and powerful tool for soft ionization in direct analysis of volatile organic compounds (VOCs).

show abstract