An evaluation of a commercial Echelle spectrometer with intensified charge-coupled device detector for materials analysis by laser-induced plasma spectroscopy
V. Detalle et al., An evaluation of a commercial Echelle spectrometer with intensified charge-coupled device detector for materials analysis by laser-induced plasma spectroscopy, SPECT ACT B, 56(6), 2001, pp. 1011-1025
In this work we evaluate the performance of a commercial Echelle spectromet
er coupled with an intensified charge-coupled device (ICCD) detector for th
e analysis of solid samples by laser-induced plasma spectroscopy (LIPS) in
air at atmospheric pressure. We compare results obtained in aluminum alloy
samples with this system and with a 'conventional' Czerny-Turner spectromet
er coupled to an intensified photodiode array (IPDA). We used both systems
to generate calibration curves and to determine the detection limit of mino
r elements, such as Mg, Cu, Si, etc. Our results indicate that no significa
nt differences in terms of analytical figures of merit exist between the Ec
helle/ICCD system and a conventional Czerny-Turner spectrometer with IPDA.
Moreover, measurements of plasma temperature and electron density using the
two assemblies give, in general, very similar results. In the second part
of this work, we aim to present a critical view of the Echelle spectrometer
for LIPS applications, by drawing up the balance sheet of the advantages a
nd limitations of the apparatus. The limitations are either inherent to the
dispersion method, or result from the dynamic range of the detector. Moreo
ver, the minimum ICCD readout time does not allow a fast data acquisition r
ate. On the other hand, the Echelle spectrometer allows complete elemental
analysis in a single shot, as spectral lines of major, minor and trace cons
tituents, as well as plasma parameters, are measured simultaneously. This e
nables a real-time identification of unknown matrices and an improvement in
the analytical precision by selecting several lines for the same element.
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