High-Power (0.4–1.2 kW) Argon Surface-Wave Plasma for Liquid Solution Analysis

Abstract

Argon surface-wave plasmas produced at power ranging from 0.5 to 1.2 kW are sustained at atmospheric pressure for the study of direct aqueous solution introduction. The plasmas are generally operated at 2450 MHz, but some results are also obtained for a 400 W 27 MHz surface-wave plasma. The emission spectra have been studied between 220 and 940 nm with a medium-resolution spectrometer and with an intensified photodiode array as detector. The effect of the operating parameters (gas flow rate, power) on intensity and signal-to-background noise ratio has been investigated for selected analytes. The detection limits were determined for several analytes (Ba, Ca, Cu, Cr, and Zn) and were found to be comparable to the detection limits obtained with other microwave-induced plasmas.