RESUMO
A new type of atomic absorption spectrometer using a laser diode as light source and a tungsten coil as atomizer is described. Compared to established atomic absorption spectrometers, it is much simpler in construction, smaller in size, and less expensive and it provides inherent background correction and high detection power. The performance of this concept is demonstrated by the determination of aluminum and chromium in water, blood serum and, using the slurry sampling technique, in powdered high-purity graphite and titanium dioxide samples. For calibration, the standard addition method was used. Possible interferences by impurities originating from the tungsten coils are discussed. Applying aqueous solutions of Al and Cr, detection limits of 0.9 and 0.03 ng/mL, respectively, were obtained, and for serum, they were 2.5 and 0.3 ng/mL, respectively. For these elements in graphite and titanium dioxide applied as slurry, the detection limits are between 0.02 (Cr in TiO2) and 0.6 micrograms/g (Al in graphite). The accuracy was checked by comparison of the results with those of other methods. The described system is especially suitable for on-site and on-line analysis.
