Hollow Cathode Discharge Ionization Mass Spectrometry: Detection, Quantification and Gas Phase Ion-Molecule Reactions of Explosives and Related Compounds

Abstract

Mass spectrometry (MS) has become an essential analytical method in every sector of science and technology. Because of its unique ability to provide direct molecular structure information on analytes, an extra method is rarely required. This review describes fabrication of a variable-pressure hollow cathode discharge (HCD) ion source for MS in detection, quantification and investigation of gas-phase ion molecule reactions of explosives and related compounds using air as a carrier gas. The HCD ion source has been designed in such a way that by altering the ion source pressures, the system can generate both HCD and conventional GD. This design enables for the selective detection and quantification of explosives at trace to ultra-trace levels. The pressure-dependent HCD ion source has also been used to investigate ion-molecule reactions in the gas phase of explosives and related compounds. The mechanism of ion formation in explosive reactions is also discussed.

Keywords:

• Adduct ions
• Birch type reduction
• explosives and related-compounds
• hollow cathode discharge (HCD) ion source
• hydride-adduct ions
• miniature-MS system
• oxidation
• real time analysis
• simultaneous detection

SUBJECT CLASSIFICATION CODES::

• Analytical Chemistry

Acknowledgements

AH expresses his gratitude to Prof. Kenzo Hiraoka of the University of Yamanashi, Japan for hiring as a postdoctoral fellow for the development of new ion sources for mass spectrometry (2011–2013). This is a brief note to thank specific colleagues, institutions, or agencies for their assistance in the authors’ work.

Declaration of competing interest

There are no competing financial interests declared by the authors.

Author contributions

HH: conceptualization, writing original draft-review, AH: conceptualization, writing original draft-review, and final review & editing, LB: conceptualization and funding acquisition. DSQ: final review & editing, LW: conceptualization, supervision, final review &editing, and funding acquisition. The published version of the manuscript has been read and approved by all authors.

Additional information

Funding

The authors acknowledge the financial support for this work by the National Key Research and Development Program of China (Grant No. 2018YFC0807404), the Yunnan Provincial Key Research and Development Program of China (Grant No. 2018BC011), the Innovative Teams Fund of “3315 Plan” in Ningbo of China (2020 A-17-C), the Entrepreneurial and Innovative Leading Team of Panyu District of Guangzhou of China (Grant No. 2017-R01-5) and the K.C. Wong Magna Fund in Ningbo University.