A highly efficient magnetically confined ion source for real time on-line monitoring of trace compounds in ambient air.

We fabricate a high-efficient ion source for real time on-line monitoring of trace compounds in ambient air by introducing a weak longitudinal magnetic field to a micro-fabricated DC glow discharge. Mass spectrometric detection of various samples indicates that the signal intensity increases by an order of magnitude and the limit of detection can be lowered to 1/10 of the original level. This improvement results from the increasing ion transport efficiency through the magnetic confinement.