Development of a High-Density Microplasma Emission Source for a Micro Total Analysis System.

To achieve a highly sensitive and onsite analysis of a small amount samples, a microplasma-based micro total analysis systems (μ-TAS) device was developed. A dielectric barrier discharge (DBD) that can generate a stable plasma at atmospheric pressure was generated in a microchip and used as the plasma source. The use of DBD suppresses the temperature rise of the electrodes and enables operation for long times because of a reduction of the electrode damage due to suppression of the current via dielectric interposing between the electrodes. It is expected that the analytical system can be miniaturized because helium plasma is generated in the microchannel contained in the microchip. Emissions from gaseous Cl, Br, and I were analyzed using the plasma source, and it was found that the detection limits for these analytes were 0.22, 0.18, and 0.14 ppm, respectively. The calibration curves for gaseous Cl, Br, and I were also plotted obtaining correlation coefficients of 0.975, 0.955 and 0.986, respectively, and showing good linearity for the developed plasma source.