Combining single-element stored spectra for the simulation of experimental spectra using multichannel detection-based ICP-AES

Abstract

Simple, linear combination of single-element stored spectra can simulate an experimental sample spectrum to facilitate line and background selection, taking into account the expected concentrations in the sample. Acquisition of UV–visible spectra with wavelength reproducibility is possible with the use of solid-state detectors, in this case an assembly of linear CCD array detectors set up on a Rowland circle. The feasibility of the procedure is illustrated with Co line selection in stainless steel at a 0.07% concentration. Because an Fe matrix does not produce significant non-spectral interferences, the influence of the operating parameters on the agreement between experimental and simulated spectra is not important, provided that the same conditions are used. In this case, it is sufficient to use the expected concentration for the computation. In contrast, for a matrix leading to non-spectral interferences, such as Na, robust plasma conditions are recommended, i.e., high power and low carrier gas flow rate, because they provide a flat change in the line intensity, regardless of the excitation energy. Instead of the concentration, a simple correction factor may be then used in the spectral combination, and may serve as an indicator of the presence of a non-spectral interference effect.