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Direct solid analysis is a rapid analytical technique without time-consuming preparation procedures and performs impressively for the determination of trace elemental compositions,especially for samples that are hazardous or difficult to digest.Many solid analytical techniques have sprung up over the last few decades,such as X-ray fluorescence spectroscopy(XFS)[1],secondary ion mass spectrometry(SI-MS)[2],laser ionization mass spectrometry(LI-MS)[3-4],glow discharge mass spectrometry(GD-MS)[5],Although those techniques possess their own features,relatively complicated experimental arrangements sometimes might be the limitation for their wider application.Besides,the trend toward atmospheric analytical tools is accelerated with the increasing need for the simple equipment,simplified operation and in situ analysis.In this respect,a new,compact needle-plane discharge apparatus using nitrogen at atmospheric pressure has been developed and employed as an ablation source.A crater with diameter of 500 μm ablated by needle tip discharge is formed.Comprehensive evidences,including voltage-current relationship,current density and electron density,suggest that the system operates in the arc regime.Three ionization mechnism are proposed to be responsible for formation of N2+,which mainly contribute to the process of ablation.The combination of the system with inductively coupled plasma mass spectrometry is a powerful technique with relative standard deviation less than 15%.Outstanding linearities are obtained for most elements contained in two set of matrix-matched samples with limits of detection down to 10 ng/g.