ATMOSPHERIC-PRESSURE ARGON SURFACE-WAVE PLASMA (SWP) AS AN ION-SOURCE IN ELEMENTAL MASS-SPECTROMETRY

Results of the study of a high-power argon surface-wave plasma as an ion source for mass spectrometric elemental analysis of aqueous solutions are presented. The plasma is operated at power levels between 475 and 800 W and at gas flow rates between 4 and 6 L/min. The wet aerosol obtained by ultrasonic nebulization is directly carried into the plasma, without the use of a desolvation system. Effects on the mass spectrum of parameters such as sampling depth and applied power were studied. With this source, indicative detection limits for most of the studied elements were in the range of 0.5 to 5 ng/mL, and the dynamic range covered 4 to 5 orders of magnitude. Analytical figures of merit obtained with the surface-wave plasma are compared with those of an inductively coupled plasma with the use of the same mass spectrometer system.