Atmospheric pressure chemical ionization of explosives using alternating current corona discharge ion source

作者：Usmanov D T; Chen L C; Yu Z; Yamabe S; Sakaki S; Hiraoka K^*

来源：Journal of Mass Spectrometry, 2015, 50(4): 651-661.

DOI：10.1002/jms.3552

• explosives
• corona discharge
• atmospheric pressure chemical ionization
• on-site mass spectrometry
• transition state

The high-sensitive detection of explosives is of great importance for social security and safety. In this work, the ion source for atmospheric pressure chemical ionization/mass spectrometry using alternating current corona discharge was newly designed for the analysis of explosives. An electromolded fine capillary with 115 mu m inner diameter and 12mm long was used for the inlet of the mass spectrometer. The flow rate of air through this capillary was 41ml/min. Stable corona discharge could be maintained with the position of the discharge needle tip as close as 1mm to the inlet capillary without causing the arc discharge. Explosives dissolved in 0.5 mu l methanol were injected to the ion source. The limits of detection for five explosives with 50 pg or lower were achieved. In the ion/molecule reactions of trinitrotoluene (TNT), the discharge products of NOx- (x= 2,3), O-3 and HNO3 originating from plasma-excited air were suggested to contribute to the formation of [TNT - H](-) (m/z 226), [TNT - NO](-) (m/z 197) and [TNT - NO+HNO3] (-) (m/z 260), respectively. Formation processes of these ions were traced by density functional theory calculations.

• 出版日期2015-4
• 单位沈阳师范大学