COMPARISON OF DESOLVATION EFFECTS WITH AQUEOUS AND ORGANIC (CARBON-TETRACHLORIDE) SAMPLE INTRODUCTION FOR INDUCTIVELY COUPLED PLASMA ATOMIC EMISSION-SPECTROMETRY

The effects of desolvation on plasma excitation characteristics have been studied for an atmospheric pressure argon inductively coupled plasma. A comparison between organic and aqueous solvent introduction in terms of emission spectra, height profiles and ion to atom intensity ratio measurements has demonstrated that desolvation using organic solvents influences all of the above parameters strongly, whereas the effect of desolvation with aqueous solvents is much less pronounced. Plasma excitation temperatures have been observed to decrease with increasing solvent vapour loading, when controlled with a variable temperature condenser. The differing roles of several major carbon species in the plasma have been observed, and C2 has been identified as the species dominating plasma properties. It is suggested that the main impact of desolvation with organic solvents is to reduce the C2 species population in the plasma, which in turn strongly influences plasma temperatures.