Use of aerosol processing and nitrogen-argon plasmas for reduction of oxide interference in inductively coupled plasma mass spectrometry

Abstract

The results of a detailed study carried out for uranium suggest that the addition of 8% of nitrogen to the outer gas is often a more effective means of reducing oxide interferences in inductively coupled plasma mass spectrometry than reduction of the water loading of an all-argon plasma by spray-chamber cooling or partial desolvation of the aerosol. The beneficial effect of the addition of nitrogen is enhanced, however, by combination with reduction of the water loading. A dramatic reduction in the argon oxide background peak is also observed. The practicality of this approach has been demonstrated by applications to difficult determinations in marine sediment and freshwater reference materials.