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Low‐pressure barrier discharge ion source using air as a carrier gas and its application to the analysis of drugs and explosives
Author(s) -
Usmanov Dilshadbek T.,
Yu Zhan,
Chen Lee Chuin,
Hiraoka Kenzo,
Yamabe Shinichi
Publication year - 2016
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/jms.3732
Subject(s) - pentaerythritol tetranitrate , chemistry , analyte , ion , dielectric barrier discharge , analytical chemistry (journal) , trinitrotoluene , atmospheric pressure , mass spectrometry , ion source , ionization , chromatography , explosive material , electrode , organic chemistry , oceanography , geology
In this work, a low‐pressure air dielectric‐barrier discharge (DBD) ion source using a capillary with the inner diameter of 0.115 and 12 mm long applicable to miniaturized mass spectrometers was developed. The analytes, trinitrotoluene (TNT), 1,3,5‐trinitroperhydro‐1,3,5‐triazine (RDX), 1,3,5,7‐tetranitroperhydro‐1,3,5,7‐tetrazocine (HMX), pentaerythritol tetranitrate (PETN), nitroglycerine (NG), hexamethylene triperoxide diamine (HMTD), caffeine, cocaine and morphine, introduced through the capillary, were ionized by a low‐pressure air DBD. The ion source pressures were changed by using various sizes of the ion sampling orifice. The signal intensities of those analytes showed marked pressure dependence. TNT was detected with higher sensitivity at lower pressure but vice versa for other analytes. For all analytes, a marked signal enhancement was observed when a grounded cylindrical mesh electrode was installed in the DBD ion source. Among nine analytes, RDX, HMX, NG and PETN could be detected as cluster ions [analyte + NO 3 ] − even at low pressure and high temperature up to 180 °C. The detection indicates that these cluster ions are stable enough to survive under present experimental conditions. The unexpectedly high stabilities of these cluster ions were verified by density functional theory calculation. Copyright © 2016 John Wiley & Sons, Ltd.