Trace analysis of zinc and bismuth in high purity tin by polarized zeeman atomic absorption spectrometry with direct atomization of solid samples

Abstract

Traces of zinc and bismuth in small amounts of high purity tin (0.5 ∼ 25 mg) were determined by polarized Zeeman AAS with direct atomization of a solid sample in a electrothermal graphite-cup cuvette. Standard solutions of zinc and bismuth were employed for the calibration curve. Absorption intensities (peak areas of the absorption signals) for zinc and bismuth were not influenced by the residual tin in a graphite-cup cuvette, up to 25 mg for zinc and up to 10 mg for bismuth. The relative standard deviations of analytical results were 9 ∼ 43% for 0.002 ∼ 0.05 ppm of zinc and 5 ∼ 10 % for 0.06 ∼ 1.3 ppm of bismuth. Detection limits were 0.012 ng for zinc and 0.03ng for bismuth. These values correspond to 0.0005 ppm of zinc in 25 mg of tin and 0.03 ppm of bismuth in 10 mg of tin. Time (incl. weighing the sample) required for analyzing one sample was about 5 min.