Characterization of a Miniturized Low Temperature Plasma Ionization Source for Mass Spectrometry (2013)

Undergraduates: Tyler Fletcher, Brandon Gaston-Thomas Santiago

Faculty Advisor: Gary Glish
Department: Chemistry

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A low temperature plasma (LTP) probe for ambient desorption ionization has been developed and characterized for use in mass spectrometry. The LTP probe consists of a copper outer electrode surrounding a glass capillary, an inner wire electrode, and discharge gas flow through the capillary. Low temperature plasma is generated inside the LTP probe when a sufficiently high AC potential is applied to the outer electrode, exceeding the breakdown voltage of the discharge gas. A miniaturized version of the low temperature probe was created to limit the usage of discharge gas and allow for plasma generation at lower potentials. The dimensions of the mini-LTP probe were optimized to maximize analyte signal by changing the length of the capillary, the outer electrode length, and the applied potential. Spectra were obtained for various analytes while testing different sampling methodologies.