title: Nitrogen microplasma generated in chip-based ingroove glow discharge device for detection of organic fragments by optical emission spectrometry.
abstract: In this study, nitrogen was successfully used to maintain the microplasma discharge to excite and detect organic compounds for the first time. A new nitrogen glow discharge microplasma-generated in-chip-based ingroove device was developed and applied as the excitation source for optical emission spectrometry. The unique ingroove design of the discharge chamber can provide good stability and sensitivity for nitrogen microplasma to detect trace organic samples. Unlike argon/helium microplasmas, the nitrogen microplasma has a strict demand on the material of electrodes, especially cathodes. We tested the effects of four common electrode materials from various aspects and obtained the most appropriate material for nitrogen glow discharge, namely, platinum. We also studied the excitation and detection mechanism of organic compounds in nitrogen microplasma and confirmed that the main means of excitation in nitrogen plasma was through energy transfer rather than penning ionization. Several organic compounds were directly injected and detected in the optimized working conditions with the limits of detection at the hundreds of picograms level. Because of the portable nitrogen generators handily and commercially available, this detection system with nitrogen as the discharge gas can overcome the limitation of noble gas supply. In addition, the advantages of small size, low energy consumption, good stability, and reproducibility demonstrate that the nitrogen ingroove microplasma source can be applied in a portable detector for on-site and real-time spectrometry detection.
authors.affiliation: Research Center of Analytical Instrumentation, Analytical &Testing Center, Sichuan University , Chengdu, China.
authors.forename: Fanying
authors.initials: F
authors.lastname: Meng
authors.forename: Yixiang
authors.initials: Y
authors.lastname: Duan