A Windowed Slew-Scanning Fourier Transform Spectrometer for Inductively Coupled Plasma Emission Spectrometry

Abstract

As an atomic emission measurement system in the uv and visible spectral regions, Fourier transform spectrometry (FTS) has excellent simultaneous multielement analysis capabilities. Quantitatively, however, it suffers from the “multiplex disadvantage” and from dynamic range limitations. To improve the quantitative performance of FTS, a novel instrument, a windowed slew-scan Fourier transform spectrometer (WSS-FTS) is proposed. This instrument consists of a slew-scanning monochromator with wide entrance and exit slits coupled to the Michelson interferometer. Accurate wavelength identification and resolution and simultaneous multielement measurement within a 4-nm spectral window are provided by the interferometer, while the monochromator provides a flexible method of selecting different spectral windows. It is shown that WSS-FTS reduces both dynamic range problems and the signal-to-noise limitations of conventional FTS. With WSS-FTS as the measurement system for emission from an inductively coupled plasma (ICP), detection limits are found to be comparable with those obtained from a commercially available ICP instrument.