Simultaneous Determination of Metals in Coal with Low-Resolution Continuum Source Atomic Absorption Spectrometer and Filter Furnace Atomizer
The setup including low-resolution spectrometer with the charge-coupled device (CCD) detector, continuum radiation source and filter furnace (FF) atomizer was employed for direct simultaneous determination of Al, Fe, Mg, Cu and Mn in coal slurry. In the FF, sample vapour entered absorption volume by filtering through heated graphite. Absorption spectrum within 200–400 nm was repeatedly recorded during the atomization period with spectral resolution 0.3 nm. The output of the CCD elements was measured within each spectrum, atomic absorption at specific wavelengths measured and corrected with respect to the linearization algorithm, and integrated. Calibration was performed using carbon slurry impregnated by the analyte metals as well as with the analytes added to the slurries as multi-element solutions. The comparison showed preference of the second method, which provides for 60 % of measurements the results within 10 % deviation range from the certified reference data independent of concentration of the analyte. Low-resolution spectral instrument with fast CCD detection makes possible simultaneous detection of transient absorption signals for several elements. The use of continuum light source makes it possible to determine broad range of concentrations without slurry dilution.
Keywords: Coal slurry, electrothermal atomic absorption spectrometry, simultaneous multi-element determination, filter furnace atomizer