Direct determination of trace metajls in solid samples by atomic absorption spectrometry with electrothermal atomizers: Part 3. Application of an Autosampler to the Determination of Silver,Bismuth, Cadmium and Zinc in Steels

A modification of the Varian-Techtron autosampler ASD-53 to accept solid samples and to operate under non-isothermal as well as isothermal conditions is described. The performance of the autosampler is illustrated for the determination of silver, bismuth, cadmium and zinc in high- and low-alloy steels with the CRA 90 graphite cup and isothermal atomization. Good agreement with certified or reported values was obtained, with relative standard deviations of 3.8–30%. Peak height and peak area evaluations were compared; the use of peak area values gives considerably better precision for silver, bismuth and cadmium. The non-specific absorption caused by the matrix was measured in the region 200–350 nm. For the resonance lines used, the background level was found to be 0.00–0.03 units (absorbance X seconds) depending on element and the age of the cup.