Simultaneous multi-element determination in electrothermal atomic-absorption spectrometry with electrothermal atomization

Abstract

A discussion of the prospects for creating a multi-element atomic absorption (AA) spectrometer leads to the conclusion regarding the expediency of using spectral devices of relatively low resolution. Previous studies showed that the spectrometer with instrumental bandwidth 0.12 nm equipped with a CCD detector could provide the absorption measurements within a wavelength range of 200 – 400 nm using low-noise radiation sources, e.g., deuterium or low current xenon lamps. The rate of data acquisition was sufficient for vapour spectra monitoring during the pulse atomisation in graphite furnace atomizer. The loss in sensitivity due to low resolution is compensated by the possibility of direct determination of several elements in a single liquid or powder sample. Feasibility of multi-element simultaneous AA spectrometry depends on the efficiency of atomization technique and technology of data processing. The concurrent problems are discussed by the example of new calculation algorithm and its application to the analysis of multi-element nitrate and halogen containing reference materials. It is shown that linearization of the calibration curves for about 10 – 15 elements, which are not subject to chemical impacts, can be carried out automatically in a concentration range up to 4 – 5 orders of magnitude with 5 – 10 % deviation from the linearity at the ends of the interval. For the elements forming stable molecular compounds further improvement of the atomization technique is required.