Reduction of Spectral Interferences in Inductively Coupled Plasma-Atomic Emission Spectrometry by Selective Spectral-Line Modulation

摘要

Spectral interferences in inductively coupled plasma (ICP) emission spectrometry can be significantly reduced through the use of selective spectral-line modulation (SLM). In this method, a mirrored, rotating chopper directs the emission from an ICP alternately through and around a flame; selective modulation is achieved when the flame contains absorbing atoms identical to emitting atoms in the ICP. The ability of SLM to minimize broad-band, narrow line and scattered light spectral interferences is demonstrated. Signal-to-background ratios for SLM detection are shown to higher than those obtained by conventional detection. The effect of modulating conditions on working curve slope and linearity is discussed and the limitations of the SLM method are critically evaluated.