Discrimination against atomic-emission spectral interferences in wavelength-modulated continuum source excited flame atomic-fluorescence spectrometry

Abstract

The extent of spectral interferences at commonly used analytical atomicfluorescence lines was demonstrated to be severe enough to necessitate the exploration of possible instrumental approaches to discriminate against the more serious type of spectral interference, namely the atomic emission of concomitant metals in samples. Two novel methods of double modulation were incorporated into the instrumentation in order to allow such discrimination. The two methods were evaluated with respect to their effect on detection limits and their effect on the particularly severe interference of potassium emission at 404.4 nm on lead fluorescence at 405.8 nm.