Extraction discharge source for argon inductively coupled plasma atomic emission spectrometry: examination of analytical potentials in the detection of a range of elements and fundamental properties

Abstract

An extraction discharge was formed at the tail flame of an Ar inductively coupled plasma (ICP) for atomic emission spectrometry. Analytical performance was measured for 19 elements at 46 different wavelengths for the supplementary discharge and for the Ar ICP alone. Detection limits of the Ar ICP used with the extraction discharge were generally lower than those for the Ar ICP alone. While detection limits measured at Ca II 370.60, Ca II 373.69, Zn II 202.55, Zn I 213.86, Mg II 279.55 Mg II 280.27, Mn II 293.30, Mn II 293.93 and Mn II 294.92 nm were improved by a factor of 8–44 in the presence of the extraction discharge, the enhancement in detection power was not significant (less than a factor of five) for the majority of the elements tested. Compared with the conventional Ar ICP, higher excitation and rotational temperatures were measured for the extraction discharge. Electron number densities measured in the presence of the extraction discharge (at 26 mm) were approximately the same as that of an Ar ICP alone (at 18 mm). These results were compared with the data obtained previously for an extraction discharge and with those found in ICP mass spectrometry.