STUDIES WITH DESOLVATION IN INDUCTIVELY COUPLED PLASMA MASS-SPECTROMETRY

The influence of water loading in the plasma on the signals of ions has been studied using an inductively coupled plasma-mass spectrometer with a sample introduction system consisting of a concentric nebulizer, a spray chamber and a desolvator (i.e. a heater and a condenser). The amount of water vapor introduced into the plasma was changed by changing the cooling temperature of the condenser. The ratios of Ba2+/Ba+, BaO+/Ba+ and ArO+/Co+ decreased with decreasing amount of water vapor. Spectroscopic interferences arising from rare earth oxide and hydroxide ions were lowered by approximately one order of magnitude with the condenser cooled to 0°C, compared with those obtained using conventional sample introduction. Rare earth element impurities, such as Tm and Lu suffering interference from GdOH+, in Gd2O3, were determined with the desolvator. Ion kinetic energies are also given with and without desolvation. © 1990.