The Use of Sample Modulation to Simplify the Experimental Arrangement of Selective Line Modulation in Atomic Emission Spectrometry

Abstract

Selective spectral line modulation (SLM) is a technique used in atomic spectrometry for recovering analyte signals in the presence of spectral interferences, such as overlapping lines from matrix concomitants and background features from the emission source. Application of SLM usually requires passing the analytical source emission through what is essentially a modulated atom reservoir. In previous work, this system was designed with the use of an array of optical choppers, mirrors, and lenses that directed the radiation through and around a standard atomic-absorption slot burner. In the present study, a sample-modulation device was used in place of this complex array. The device operates by pulsing sample aerosol into a flame, and therefore directly performs the function of a modulated atom reservoir. When used in the SLM experiment, this device considerably simplifies the experimental arrangement. Comparisons are made between the conventional optical arrangement and the sample-modulation device.