To minimize problems caused by sample introduction into a microwave-induced plasma (MIP), we have developed a system consisting of a spark ablation cell and a pulse-operated microwave-induced plasma (pulsed-MIP). An aerosol is generated from solid samples with the use of a spark discharge. The resultant material is swept into a pulsed-MIP. Design and fabrication criteria for the spark source and the spark ablation cell are presented. The combined sources show enhanced precision, stability, signal-to-noise levels, and detection limits relative to direct spark emission. Analytical calibration curves and detection limit data are shown for nickel, manganese, and chromium in steel samples. Time-resolved data are also shown.
M. M. Mohamed, T. Uchida, and S. Minami, "Direct Sample Introduction of Solid Material into a Pulse-Operated MIP," Appl. Spectrosc. 43, 794-800 (1989)