Plasma quenching during hydrocarbon sample introduction via gas chromatography into a pulsed ms dc-glow discharge

Abstract

The plasma chemistry of single plasma pulses of a pulsed glow discharge was investigated during the introduction of organic solventviagas chromatography. Influencing parameters on methanol and sec-butanol introduction on the Cu+ and the ArH+ ion signals in the afterpeak of a ms pulsed glow discharge were studied. A small amount of solvent (a few hundred nano-litres absolute) injected viaGC leads to a significant quenching of the afterpeak ion signals. The recovery of the plasma after the quenching event allowed conclusions on plasma chemistry involved in the quenching. The ion population in every time domain responds inhomogeneous to a quenching agent. In the case of Cu+ initially the afterpeak recovers followed by the plateau. In the case of the Ar+ ion population the recovery is similar in all time domains. Furthermore, hydrogen introduced, as part of the hydrocarbon solvent, is leading to an increased intensity of the Cu+ intensity after the recovery from the quenching. A delayed appearance of the C+ signal was identified and is explained by carbon memory effects within the glow discharge chamber.