DIRECT DETERMINATION OF TRACE-METALS IN SOLID SAMPLES BY ATOMIC-ABSORPTION SPECTROMETRY WITH ELECTRO-THERMAL ATOMIZERS .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. © 1979.