Positive corona discharge ion source with IMS/MS to detect impurities in high purity Nitrogen

M. Sabo , M. Klas , H. Wang , C. Huang , Y. Chu , Š. Matejčík

We have applied the Ion Mobility Spectrometry/Mass Spectrometry (IMS/MS) and the Atmospheric Pressure Chemical Ionisation/Mass Spectrometry (APCI/MS) techniques to study the formation of the ions in the positive corona discharge (CD) in highly purified nitrogen with impurities at 100 ppt level. The main products observed were HO(HO) ions (reduced ion mobility of 2.15 cm V s). Additionally, we have observed ions with reduced mobilities 2.42 cm V s and 2.30 cm V s. The intensity of these ions was increasing with the increasing discharge current. We associated these peaks with NH and NO(HO). The formation of these ions results from trace amounts of O and NH in nitrogen. The time evolution of the ions in corona discharge has been studied using the APCI/MS technique in the time windows ranging from 100 s to 2 ms. The present work indicates the ability of the IMS technique equipped with CD ions source to detect impurities below 100 ppt level.

Mots clés: Physical Sciences

Domaines: Physique [physics]

M. Sabo, M. Klas, H. Wang, C. Huang, Y. Chu, et al.. Positive corona discharge ion source with IMS/MS to detect impurities in high purity Nitrogen. European Physical Journal: Applied Physics, 2011, 55 (1), ⟨10.1051/epjap/2011100437⟩. ⟨hal-00719813⟩