HIGH-POWER MICROWAVE-INDUCED PLASMA SOURCE FOR TRACE-ELEMENT ANALYSIS

A high-power microwave-induced plasma source (2.45 GHz, 1.2 kW) for trace element analysis is presented. The plasma is generated by a circularly polarized wave induced by a helical coil with a mode transformer. The sample introduction system consists of a pneumatic nebulizer with no dehydration system, i.e., utilizing direct introduction of aqueous solutions. An annular-shaped argon plasma was generated at atmospheric pressure in a 2.3-4.2-mm i.d. quartz discharge tube with a low gas flow rate (2 l/min). Preliminary analytical results were otained using an aqueous Ca(10 ppm)+Zr(200 ppm) solution sample and compared to those obtained with the argon inductively coupled plasma. © 1990 IOP Publishing Ltd.