On-line Preconcentration and Determination of Lead in Iron and Steel by Flow Injection-Flame Atomic Absorption Spectrometry

摘要

A flow injection method has been developed for the determination of lead in steel samples by coupling on-line preconcentration on a lead selective resin, Pb·Spec™, with flame atomic absorption spectrometry. The sample prepared as a nitric acid solution is passed through a column packed with Pb·Spec™. The lead retained on the column is then eluted with ammonium oxalate solution and introduced directly into the nebulizer of a flame atomic absorption spectrophotometer. The proposed method was successfully applied to the determination of lead in pure iron certified reference material [0.19 ± 0.01 ppm (n=6); certified value: 0.2 ppm] and lead-free cutting steel certified reference material [0.0952 ± 0.0008% (n=3); certified value: 0.097%]. The detection limit (3σ) was 0.05µg of lead.