Atmospheric Pressure Plasma Jet for Mass Spectrometry

The atmospheric pressure plasma is much advantageous over low pressure plasmas in various aspects, e.g. vacuum-free operation, relative low cost, flexibility of a continuous process. Among various plasmas generated in atmospheric pressure discharges there are cold plasma jets that represent a technology of great application promise (industry, medicine, biology). To generate low-temperature plasmas at atmospheric pressure the dielectric barrier discharge can be used. It is suitable for the atomization of volatile species and can also be served as a ionization source for ambient mass and ion mobility spectrometry. As the discharge is generated in a restricted electrode structure, a plasma jet (plume) is usually formed outside the electrode region (that provides spatial separation of the plasma generation and surface processing regions). The paper presents a source based on a plasma jet established at the end of a capillary dielectric barrier discharge at atmospheric pressure and its application to mass spectrometry. The structure of the jet generator consists of piezoelectric transformer and two concentric and symmetric electrodes, between which the working gas flows at definite rate. Besides the source description early results of spectroscopic analysis are also given.