A single-electrode atmospheric pressure microwave discharge air-plasma is reported. Fundamental characteristics, such as the effects of microwave power, auxiliary air flow, and nebulizer air flow on emission intensity, detection limits, and dynamic ranges for twelve elements and several interference experiments are reported. The plasma temperature is found to be about 4700°K. This simple system can be applied to the spectrochemical analysis of solution samples. The results with the use of this system to determine calcium, sodium, and potassium in SRM-1566 (oyster tissue) and SRM-92 (low-boron glass) show excellent agreement with the NBSs certified values.
Y. K. Zhang, S. Hanamura, and J. D. Winefordner, "Evaluation of Microwave-Induced Air-Plasma as an Excitation Source," Appl. Spectrosc. 39, 226-230 (1985)